Chair
A chair is a stable, raised surface used to sit on, commonly for use by one person. Chairs are most often supported by four legs and have a back; however, a chair can have three legs (in a triangle shape) or could have a different shape depending on the criteria of the chair specifications. A chair without a back or arm rests is a stool, or when raised up, a bar stool. A chair with arms is an armchair and with folding action and inclining footrest, a recliner. A permanently fixed chair in a train or theater is a seat or airline seat; when riding, it is a saddle and bicycle saddle, and for an automobile, a car seat or infant car seat. With wheels it is a wheelchair and when hung from above, a swing.
The chair is of extreme antiquity and simplicity, although for many centuries and indeed for thousands of years it was an article of state and dignity rather than an article of ordinary use. “The chair” is still extensively used as the emblem of authority in the House of Commons in the United Kingdom and Canada, and in many other settings. Committees, boards of directors, and academic departments all have a ‘chairman’. Endowed professorships are referred to as chairs. It was not, in fact, until the 16th century that it became common anywhere. The chest, the bench and the stool were until then the ordinary seats of everyday life, and the number of chairs which have survived from an earlier date is exceedingly limited; most of such examples are of ecclesiastical or seigneurial origin. Our knowledge of the chairs of remote antiquity is derived almost entirely from monuments, sculpture and paintings.
List of national birds
National birds
[edit] See also
Guava
The term “guava” appears to derive from Arawak guayabo “guava tree”, via the Spanish guayaba. It has been adapted in many European languages: guava (Romanian, Swedish, Danish and Norwegian, also Greek Γκουάβα and Russian Гуава), Guave (Dutch and German), goyave (French), gujawa (Polish), goiaba (Portuguese).
Outside of Europe, the Arabic jwafa, the Japanese guaba , the Tamil “koiyaa” (கொய்யா), the Tongan kuava and probably also the Tagalog bayabas are ultimately derived from the Arawak term.
Another term for guavas is pera or variants thereof. It is common around the western Indian Ocean and probably derives from Spanish or Portuguese, which means “pear”, or from some language of southern India, though it is so widespread in the region that its origin cannot be clearly discerned any more. Pera itself is used in Malayalam, Sinhala and Swahili. In Marathi it is peru (पेरू), in Bengali pearah (পেয়ারা), in Kannada it is pearaley (‘ಪೇರಲೆ’) or seebe kaayi (‘ಸೀಬೇಕಾಯಿ ‘) and in Dhivehi feyru. In Telugu language it is “Jama kaya”. Guava is also called Amrood (‘अमरुद’) in northern India, although its etymology is not clear.
Additional terms for guavas from their native range are, for example, sawintu (Quechua) and xālxocotl (Nāhuatl)
Ecology and uses
Apple Guava flower
Psidium species are used as food plants by the caterpillars of some Lepidoptera, mainly moths like the Ello Sphinx (Erinnyis ello), Eupseudosoma aberrans, E. involutum, and Hypercompe icasia. Mites like Pronematus pruni and Tydeus munsteri are known to parasitize the Apple Guava (P. guajava) and perhaps other species. The bacterium Erwinia psidii causes rot diseases of the Apple Guava.
The fruit are not only relished by humans, but by many mammals and birds as well. The spread of introduced guavas owes much to this fact, as animals will eat the fruit and disperse the seeds in their droppings.
In several tropical regions, including Hawaii, some species (namely Strawberry Guava, P. littorale, and to a lesser extent Apple Guava Psidium guajava) have become invasive species. On the other hand, several species have become very rare due to habitat destruction and at least one (Jamaican Guava, P. dumetorum), is already extinct.
Guava wood is used for meat smoking in Hawaii and is being used at barbecue competitions across the United States. In Cuba the leaves are also used in barbecues, providing a smoked flavor and scent to the meat.
Cultivation for fruit
Guavas are cultivated in many tropical and subtropical countries for their edible fruit. Several species are grown commercially; apple guava (P. guajava) and its cultivars are those most commonly traded internationally.
Psidium guajava 1-year seedling
Mature trees of most species are fairly cold-hardy and can survive as low as 5 °C (41 °F) for short periods of time, but younger plants will not survive. They are known to survive in Northern Pakistan where they can get down to 5°C or lower during the night. A few species – notably strawberry guavas – can survive temperatures several degrees below freezing for short periods of time.
Strawberry guava, 1 year old seedling
Guavas are also of interest to home growers in temperate areas, being one of the few tropical fruits that can grow to fruiting size in pots indoors. When grown from seed, guavas can bloom and bear fruit as soon as two years, or as long as eight years.
Guava fruit
Guava fruit, usually 4 to 12 cm long, are round or oval depending on the species. The outer skin may be rough, often with a bitter taste, or soft and sweet. Varying between species, the skin can be any thickness, is usually green before maturity, but becomes yellow, maroon, or green when ripe.
Guava fruit generally have a pronounced and typical fragrance, similar to lemon rind but less sharp. Guava pulp may be sweet or sour, off-white (“white” guavas) to deep pink (“red” guavas), with the seeds in the central pulp of variable number and hardness, depending on species.
Culinary uses
In Hawaii, guava fruit is eaten with soy sauce and vinegar. Occasionally, a pinch of sugar and black pepper are added to the soy sauce and vinegar mixture. The guava fruit is cut up and dipped into the sauce.
In Pakistan and India, guava fruit is often eaten raw, typically cut into quarters with a pinch of salt and pepper and sometimes cayenne powder/masala. Street vendors often sell guava fruit for a couple of rupees each.
In the Philippines, ripe guava is used in cooking sinigang.
The fruit is also often prepared as a dessert, in fruit salads. In Asia, fresh guava slices are often dipped in preserved prune powder or salt. In India it is often sprinkled with red rock salt, which is very tart.
Because of the high level of pectin, guavas are extensively used to make candies, preserves, jellies, jams, marmalades (Brazilian goiabada), and also for juices and aguas frescas.
Guava juice is very popular in Hawaii, Cuba, Puerto Rico, Colombia, Venezuela, Egypt, Mexico, and South Africa.
“Red” guavas can be used as the base of salted products such as sauces, substituting for tomatoes, especially for those sensitive to the latter’s acidity. In Asia, a drink is made from an infusion of guava fruits and leaves. In Brazil, the infusion made with guava tree leaves (chá-de-goiabeira, i.e. “tea” of guava tree leaves) is considered medicinal.
Ripe apple guavas for sale in Bangalore, India
Nutritional value
Guavas are often included among superfruits, being rich in dietary fiber, vitamins A and C, folic acid, and the dietary minerals, potassium, copper and manganese. Having a generally broad, low-calorie profile of essential nutrients, a single common guava (P. guajava) fruit contains about four times the amount of vitamin C as an orange.
However, nutrient content varies across guava cultivars. Although the strawberry guava (P. littorale var. cattleianum), notably containing 90 mg of vitamin C per serving, has about 25% of the amount found in more common varieties, its total vitamin C content in one serving still provides 100% of the Dietary Reference Intake for adult males.
G’uavas contain both carotenoids and polyphenols like (+)-gallocatechin, guaijaverin, leucocyanidin and amritoside– the major classes of antioxidant pigments – giving them relatively high potential antioxidant value among plant foods. As these pigments produce the fruit skin and flesh color, guavas that are red-orange have more pigment content as polyphenol, carotenoid and pro-vitamin A, retinoid sources than yellow-green ones.
Since the 1950s, guavas – particularly the leaves – have been a subject for diverse research in chemical identity of their constituents, pharmacological properties and history in folk medicine. Most research, however, has been conducted on apple guava (P. guajava), with other species remaining undefined. From preliminary medical research in laboratory models, extracts from apple guava leaves or bark are implicated in therapeutic mechanisms against cancer, bacterial infections, inflammation and pain. Essential oils from guava leaves display anti-cancer activity in vitro.
Guava leaves are used in folk medicine as a remedy for diarrheaand, as well as the bark, for their supposed antimicrobial properties and as an astringent. Guava leaves or bark are used in traditional treatments against diabetes.In Trinidad, a tea made from young leaves is used for diarrhea, dysentery and fever.
Selected species
Strawberry Guava, Psidium littorale var. cattleianum
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the “true grasses”, of the Poaceae (or Gramineae) family, as well as the sedges (Cyperaceae) and the rushes (Juncaceae).
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the “true grasses”, of the Poaceae (or Gramineae) family, as well as the sedges (Cyperaceae) and the rushes (Juncaceae). The true grasses include cereals, bamboo and the grasses of lawns (turf) and grassland. Sedges include many wild marsh and grassland plants, and some cultivated ones such as water chestnut (Eleocharis dulcis) and papyrus sedge (Cyperus papyrus). Uses for graminoids include food (as grain, sprouted grain, shoots or rhizomes), drink (beer, whisky), pasture for livestock, thatch, paper, fuel, clothing, insulation, construction, sports turf, basket weaving and many others.
A kangaroo eating grass
Graminoids are among the most versatile life forms. They became widespread toward the end of the Cretaceous period, and fossilized dinosaur dung (coprolites) have been found containing phytoliths of a variety of grasses that include grasses that are related to modern rice and bamboo.[1] Grasses have adapted to conditions in lush rain forests, dry deserts, cold mountains and even intertidal habitats, and are now the most widespread plant type; grass is a valuable source of food and energy for all sorts of wildlife and organics.
Graminoids are the dominant vegetation in many habitats, including grassland, salt-marsh, reedswamp and steppes. They also occur as a smaller part of the vegetation in almost every other terrestrial habitat.
There are some 3,500 species of graminoids.[2]
Many types of animals eat grass as their main source of food, and are called graminivores – these include cattle, sheep, horses, rabbits and many invertebrates, such as grasshoppers and the caterpillars of many brown butterflies. Grasses are also eaten by omnivorous or even occasionally by primarily carnivorous animals.
In the study of ecological communities, herbaceous plants are divided into graminoids and forbs, which are herbaceous dicotyledons, mostly with broad leaves.
School
A school is an institution designed for the teaching of students (or “pupils”) under the direction of teachers. Most countries have systems of formal education, which is commonly compulsory. In these systems, students progress through a series of schools. The names for these schools vary by country (discussed in the Regional section below), but generally include primary school for young children and secondary school for teenagers who have completed primary education. An institution where higher education is taught, is commonly called a university college or university.
In addition to these core schools, students in a given country may also attend schools before and after primary and secondary education. Kindergarten or pre-school provide some schooling to very young children (typically ages 3–5). University, vocational school, college or seminary may be available after secondary school. A school may also be dedicated to one particular field, such as a school of economics or a school of dance. Alternative schools may provide nontraditional curriculum and methods.
There are also non-government schools, called private schools. Private schools may be for children with special needs when the government does not supply for them; religious, such as Christian schools, hawzas, yeshivas, and others; or schools that have a higher standard of education or seek to foster other personal achievements. Schools for adults include institutions of corporate training, Military education and training and business schools.
In homeschooling and online schools, teaching and learning take place outside of a traditional school building.
Tiger
The tiger (Panthera tigris) is the largest cat species, reaching a total body length of up to 3.3 metres (11 ft) and weighing up to 306 kg (670 lb). Their most recognizable feature is a pattern of dark vertical stripes on reddish-orange fur with lighter underparts. They have exceptionally stout teeth, and their canines are the longest among living felids, with a crown height of up to 74.5 mm (2.93 in).[4]
Tigers once ranged widely across Asia, from Turkey in the west to the eastern coast of Russia. Over the past 100 years, they have lost 93% of their historic range, and have been extirpated from southwest and central Asia, from the islands of Java and Bali, and from large areas of Southeast and Eastern Asia. Today, they range from the Siberian taiga to open grasslands and tropical mangrove swamps. The remaining six tiger subspecies have been classified as endangered by IUCN. Since 2001, their range has shrunk by 41%. The global population in the wild is estimated at ranging from 3,062 to 5,066, with most remaining populations occurring in small pockets that are isolated from each other. Major reasons for population decline include habitat destruction, habitat fragmentation and poaching.[1]
They are territorial and generally solitary animals, often requiring large contiguous areas of habitat that support their prey requirements. This, coupled with the fact that they are indigenous to some of the more densely populated places on earth, has caused significant conflicts with humans.
In zoos, tigers have lived for 20 to 26 years, which also seems to be their longevity in the wild.[5]
Tigers are among the most recognisable and popular of the world’s charismatic megafauna. They have featured prominently in ancient mythology and folklore, and continue to be depicted in modern films and literature. Tigers appear on many flags, coats of arms, and as mascots for sporting teams.[6] The Bengal tiger is the national animal of Bangladesh and India.[7]
Naming and etymology
The word “tiger” is taken from the Greek word “tigris“, which is possibly derived from a Persian source meaning “arrow”, a reference to the animal’s speed and also the origin for the name of the Tigris river.[8][9] In American English, “tigress” was first recorded in 1611. It was one of the many species originally described by Linnaeus in his 18th century work, Systema Naturae: he called it Felis tigris.[3][10] The generic component of its scientific designation, Panthera tigris, is often presumed to derive from Greek pan- (“all”) and theron (“beast”), but this may be a folk etymology. Although it came into English through the classical languages, panthera is probably of Indian origin, meaning “the yellowish animal”, or “whitish-yellow”.[11]
Tigers rarely form groups (see below), but the collective nouns applied when they do are either “ambush” or “streak”.[12][13]
Range of the tiger in 1900 and 1990
Distribution and habitat
In the past, tigers were found throughout Asia, from the Caucasus and the Caspian Sea to Siberia and the Indonesian islands of Java, Bali and Sumatra. During the 20th century, tigers have been extirpated in western Asia and became restricted to isolated pockets in the remaining parts of their range. Today, their fragmented and partly degraded range extends from India in the west to China and Southeast Asia. The northern limit of their range is close to the Amur River in south eastern Siberia. The only large island inhabited by tigers today is Sumatra.[1]
Tigers were extirpated on the island of Bali in the 1940s, around the Caspian Sea in the 1970s, and on Java in the 1980s. Loss of habitat and the persistent killing of tigers and tiger prey precipitated these extirpations, a process that continues to leave forests devoid of tigers and other large mammals across South and Southeast Asia. Since the beginning of the 21st century, their historical range has shrunk by 93%. In the decade from 1997 to 2007, the estimated area known to be occupied by tigers has declined by 41%. [14]
Fossil remains indicate that tigers were present in Borneo and Palawan in the Philippines during the late Pleistocene and Holocene.[15][16]
Tiger habitats will usually include sufficient cover, proximity to water, and an abundance of prey. Bengal tigers live in many types of forests, including wet, evergreen, the semi-evergreen of Assam and eastern Bengal; the mangrove forest of the Ganges Delta; the deciduous forest of Nepal, and the thorn forests of the Western Ghats. Compared to the lion, the tiger prefers denser vegetation, for which its camouflage colouring is ideally suited, and where a single predator is not at a disadvantage compared with the multiple felines in a pride.
Among the big cats, only the tiger and jaguar are strong swimmers; tigers are often found bathing in ponds, lakes, and rivers. During the extreme heat of the day, they often cool off in pools. Tigers are excellent swimmers, and are able to carry prey through the water.
Physical characteristics, taxonomy and evolution
Video from the Disney’s Animal Kingdom
The oldest remains of a tiger-like cat, called Panthera palaeosinensis, have been found in China and Java. This species lived about 2 million years ago, at the beginning of the Pleistocene, and was smaller than a modern tiger. The earliest fossils of true tigers are known from Java, and are between 1.6 and 1.8 million years old. Distinct fossils from the early and middle Pleistocene were also discovered in deposits from China, and Sumatra. A subspecies called the Trinil tiger (Panthera tigris trinilensis) lived about 1.2 million years ago and is known from fossils found at Trinil in Java.[17]
Tigers first reached India and northern Asia in the late Pleistocene, reaching eastern Beringia (but not the American Continent), Japan, and Sakhalin. Fossils found in Japan indicate that the local tigers were, like the surviving island subspecies, smaller than the mainland forms. This may be due to the phenomenon in which body size is related to environmental space (see insular dwarfism), or perhaps the availability of prey. Until the Holocene, tigers also lived in Borneo, as well as on the island of Palawan in the Philippines.[18]
Characteristics
Siberian tiger
Tigers are muscular, have powerful forequarters, and especially in males, a large head. The ground coloration of their fur varies between tawny and xanthine orange or cinnamon brown in the southernmost populations, to between ochraceous-orange or zinc orange or capucine orange in the northernmost populations. The face is framed by long hairs that form whiskers, which are more conspicuous in males. The ventral parts are usually white. The body is marked with black or chaetura black stripes of various length, breadth and form. The pupils are circular with yellow irises. The rather small ears are rounded and black on their dorsal side with a conspicuous white central spot.[4] These spots, called ocelli, play an important role in intraspecific communication.[19]
The pattern of stripes is unique to each animal, these unique markings can be used by researchers to identify individuals (both in the wild and captivity), much in the same way that fingerprints are used to identify humans. It seems likely that the function of stripes is camouflage, serving to help tigers conceal themselves amongst the dappled shadows and long grass of their environment as they stalk their prey. The stripe pattern is also found on the skin of the tiger. If a tiger were to be shaved, its distinctive camouflage pattern would be preserved.
Skeleton
The tiger are the most variable in size of all big cats, even more so than the leopard and much more so than lions.[20] The Bengal, Caspian and Siberian tiger subspecies represent the largest living felids, and rank among the biggest felids that ever existed. Females vary in size from 240 to 275 cm (94 to 108 in), weigh 85 to 167 kg (190 to 370 lb) with a greatest length of skull ranging from 268 to 318 mm (10.6 to 12.5 in). Males vary in size from 270 to 330 cm (110 to 130 in), weigh 170 to 306 kg (370 to 670 lb) with a greatest length of skull ranging from 316 to 383 mm (12.4 to 15.1 in). Body size of different populations seems to be correlated with climate — Bergmann’s Rule — and can be explained from the point of view of thermoregulation.[4] Large male Siberian tigers can reach a total length of more than 3.5 m (11 ft) “over curves”, 3.3 m (11 ft) “between pegs” and a weight of 306 kg (670 lb). This is considerably larger than the size reached by the smallest living tiger subspecies, the Sumatran tiger, which reach a body weight of 75 to 140 kg (170 to 310 lb). At the shoulder, tigers may variously stand 0.7 to 1.22 m (2.3 to 4.0 ft) tall.[5]
Tigresses are smaller than the males in each subspecies, although the size difference between male and female tigers tends to be more pronounced in the larger tiger subspecies, with males weighing up to 1.7 times more than the females.[21] In addition, male tigers have wider forepaw pads than females. Biologists use this difference to determine gender based on tiger tracks.[22] The skull of the tiger is very similar to that of the lion, though the frontal region is usually not as depressed or flattened, with a slightly longer postorbital region. The skull of a lion has broader nasal openings. However, due to the amount of skull variation in the two species, usually, only the structure of the lower jaw can be used as a reliable indicator of species.[23]
Subspecies
A Bengal tigress with her cub.
There are nine recent subspecies of tiger, three of which are extinct. Their historical range (severely diminished today) ran through Bangladesh, Siberia, Iran, Afghanistan, India, China, and southeast Asia, including some Indonesian islands. The surviving subspecies, in descending order of wild population, are:
- The Bengal tiger or the Royal Bengal tiger (Panthera tigris tigris) is the most common subspecies of tiger and is found primarily in India and Bangladesh.[24] It lives in varied habitats: grasslands, subtropical and tropical rainforests, scrub forests, wet and dry deciduous forests, and mangroves. Males in the wild usually weigh 205 to 227 kg (450 to 500 lb), while the average female will weigh about 141 kg.[25] However, the northern Indian and the Nepalese Bengal tigers are somewhat bulkier than those found in the south of the Indian Subcontinent, with males averaging around 235 kilograms (520 lb).[25] While conservationists already believed the population to be below 2,000,[26] the most recent audit by the Indian Government’s National Tiger Conservation Authority has estimated the number at just 1,411 wild tigers (1165–1657 allowing for statistical error), a drop of 60% in the past decade.[27] Since 1972, there has been a massive wildlife conservation project, known as Project Tiger, to protect the Bengal tiger. Despite increased efforts by Indian officials, poaching remains rampant and at least one Tiger Reserve (Sariska Tiger Reserve) has lost its entire tiger population to poaching.[28] The passing of the Forest Rights Act by the Indian government in 2006 has worsened the situation as evidence has shown that human habitats and tigers cannot co-exist and has pushed the Indian tiger on the brink of extinction.[29] However, another census by the government in 2011 using better counting methods showed a rise of 20%, taking the numbers to 1,706.[30]
- The Indochinese Tiger (Panthera tigris corbetti), also called Corbett’s tiger, is found in Cambodia, China, Laos, Burma, Thailand, and Vietnam. These tigers are smaller and darker than Bengal tigers: Males weigh from 150–190 kg (330–420 lb) while females are smaller at 110–140 kg (240–310 lb). Their preferred habitat is forests in mountainous or hilly regions. Estimates of the Indochinese tiger population vary between 1,200 to 1,800, with only several hundred left in the wild. All existing populations are at extreme risk from poaching, prey depletion as a result of poaching of primary prey species such as deer and wild pigs, habitat fragmentation and inbreeding. In Vietnam, almost three-quarters of the tigers killed provide stock for Chinese pharmacies.
- The Malayan Tiger (Panthera tigris jacksoni), exclusively found in the southern part of the Malay Peninsula, was not considered a subspecies in its own right until 2004. The new classification came about after a study by Luo et al. from the Laboratory of Genomic Diversity Study,[31] part of the National Cancer Institute of the United States. Recent counts showed there are 600–800 tigers in the wild, making it the third largest tiger population, behind the Bengal tiger and the Indochinese tiger. The Malayan tiger is the smallest of the mainland tiger subspecies, and the second smallest living subspecies, with males averaging about 120 kg and females about 100 kg in weight. The Malayan tiger is a national icon in Malaysia, appearing on its coat of arms and in logos of Malaysian institutions, such as Maybank.
- The Sumatran Tiger (Panthera tigris sumatrae) is found only on the Indonesian island of Sumatra, and is critically endangered.[32] It is the smallest of all living tiger subspecies, with adult males weighing between 100–140 kg (220–310 lb) and females 75–110 kg (170–240 lb).[33] Their small size is an adaptation to the thick, dense forests of the island of Sumatra where they reside, as well as the smaller-sized prey. The wild population is estimated at between 400 and 500, seen chiefly in the island’s national parks. Recent genetic testing has revealed the presence of unique genetic markers, indicating that it may develop into a separate species,[specify] if it does not go extinct.[34] This has led to suggestions that Sumatran tigers should have greater priority for conservation than any other subspecies. While habitat destruction is the main threat to existing tiger population (logging continues even in the supposedly protected national parks), 66 tigers were recorded as being shot and killed between 1998 and 2000, or nearly 20% of the total population.
- The Siberian tiger (Panthera tigris altaica), also known as the Amur, Manchurian, Altaic, Korean or North China tiger, which is the most northernmost subspecies, is confined to the Amur–Ussuri region of Primorsky Krai and Khabarovsk Krai in far eastern Siberia, where it is now protected.[35] The largest subspecies of tiger, it has a head and body length of 160–180 cm (63–71 in) for females and 190–230+ cm (75–91 in) for males, plus a tail of about 60–110 cm long (about 270–330 cm in total length) and an average weight of around 227 kilograms (500 lb) for males,[25] the Amur tiger is also noted for its thick coat, distinguished by a paler golden hue and fewer stripes. The heaviest wild Siberian tiger on record weighed in at 384 kilograms (850 lb),[36] but according to Mazak these giants are not confirmed via reliable references.[5] Even so, a six-month old Siberian tiger can be as big as a fully grown leopard. The last two censuses (1996 and 2005) found 450–500 Amur tigers within their single, and more or less continuous, range making it one of the largest undivided tiger populations in the world. Genetic research in 2009 demonstrated that the Siberian tiger, and the western “Caspian tiger” (once thought to have been a separate subspecies that became extinct in the wild in the late 1950s[37][38]) are actually the same subspecies, since the separation of the two populations may have occurred as recently as the past century due to human intervention.[39]
- The South China tiger (Panthera tigris amoyensis), also known as the Amoy or Xiamen tiger, is the most critically endangered subspecies of tiger and is listed as one of the 10 most endangered animals in the world.[40][clarification needed] One of the smaller tiger subspecies, the length of the South China tiger ranges from 2.2–2.6 m (87–100 in) for both males and females. Males weigh between 127 and 177 kg (280 and 390 lb) while females weigh between 100 and 118 kg (220 and 260 lb). From 1983 to 2007, no South China tigers were sighted.[41] In 2007 a farmer spotted a tiger and handed in photographs to the authorities as proof.[41][42] The photographs in question, however, were later exposed as fake, copied from a Chinese calendar and digitally altered, and the “sighting” turned into a massive scandal.[43][44][45]
In 1977, the Chinese government passed a law banning the killing of wild tigers, but this may have been too late to save the subspecies, since it is possibly already extinct in the wild. There are currently 59 known captive South China tigers, all within China, but these are known to be descended from only six animals. Thus, the genetic diversity required to maintain the subspecies may no longer exist. Currently, there are breeding efforts to reintroduce these tigers to the wild.
Extinct subspecies
A hunted down Bali tiger
- The Bali tiger (Panthera tigris balica) was limited to the island of Bali. They were the smallest of all tiger subspecies, with a weight of 90–100 kg in males and 65–80 kg in females.[5] These tigers were hunted to extinction—the last Balinese tiger is thought to have been killed at Sumbar Kima, West Bali on 27 September 1937; this was an adult female. No Balinese tiger was ever held in captivity. The tiger still plays an important role in Balinese Hinduism.
A photograph of a Javan tiger.
- The Javan tiger (Panthera tigris sondaica) was limited to the Indonesian island of Java. It now seems likely that this subspecies became extinct in the 1980s, as a result of hunting and habitat destruction, but the extinction of this subspecies was extremely probable from the 1950s onwards (when it is thought that fewer than 25 tigers remained in the wild). The last confirmed specimen was sighted in 1979, but there were a few reported sightings during the 1990s.[46][47] With a weight of 100–141 kg for males and 75–115 kg for females, the Javan tiger was one of the smaller subspecies, approximately the same size as the Sumatran tiger.[citation needed]
A captive Caspian tiger, Berlin Zoological Garden 1899
- The Caspian tiger (formerly Panthera tigris virgata), also known as the Persian tiger or Turanian tiger was the westernmost population of Siberian tiger, found in Iran, Iraq, Afghanistan, Turkey, Mongolia, Kazakhstan, the Caucasus, Tajikistan, Turkmenistan, and Uzbekistan until it apparently became extinct in the late 1950s, though there have been several alleged more recent sightings of the tiger.[38] Though originally thought to have been a distinct subspecies, genetic research in 2009 suggest that the animal was largely identical to the Siberian tiger.[39]
Hybrids
Hybridisation among the big cats, including the tiger, was first conceptualised in the 19th century, when zoos were particularly interested in the pursuit of finding oddities to display for financial gain.[48] Lions have been known to breed with tigers (most often the Amur and Bengal subspecies) to create hybrids called ligers and tigons.[49] Such hybrids were once commonly bred in zoos, but this is now discouraged due to the emphasis on conserving species and subspecies. Hybrids are still bred in private menageries and in zoos in China.
The liger is a cross between a male lion and a tigress.[50] Because the lion sire passes on a growth-promoting gene, but the corresponding growth-inhibiting gene from the female tiger is absent, ligers grow far larger than either parent. They share physical and behavioural qualities of both parent species (spots and stripes on a sandy background). Male ligers are sterile, but female ligers are often fertile. Males have about a 50% chance of having a mane, but, even if they do, their manes will be only around half the size of that of a pure lion. Ligers are typically between 10 to 12 feet in length, and can be between 800 and 1,000 pounds or more.[50]
The less common tigon is a cross between the lioness and the male tiger.[51]
Colour variations
White tigers
A Bengal white tiger in Bannerghatta National Park in Bangalore
A pair of white tigers at the Singapore Zoo.
There is a well-known mutation that produces the white tiger, technically known as chinchilla albinistic,[52] an animal which is rare in the wild, but widely bred in zoos due to its popularity. Breeding of white tigers will often lead to inbreeding (as the trait is recessive). Many initiatives have taken place in white and orange tiger mating in an attempt to remedy the issue, often mixing subspecies in the process. Such inbreeding has led to white tigers having a greater likelihood of being born with physical defects, such as cleft palates and scoliosis (curvature of the spine).[53][54] Furthermore, white tigers are prone to having crossed eyes (a condition known as strabismus). Even apparently healthy white tigers generally do not live as long as their orange counterparts. Recordings of white tigers were first made in the early 19th century.[55] They can only occur when both parents carry the rare gene found in white tigers; this gene has been calculated to occur in only one in every 10,000 births. The white tiger is not a separate sub-species, but only a colour variation; since the only white tigers that have been observed in the wild have been Bengal tigers[56] (and all white tigers in captivity are at least part Bengal), it is commonly thought that the recessive gene that causes the white colouring is probably carried only by Bengal tigers, although the reasons for this are not known.[53][57] Nor are they in any way more endangered than tigers are generally, this being a common misconception. Another misconception is that white tigers are albinos, despite the fact that pigment is evident in the white tiger’s stripes. They are distinct not only because of their white hue; they also have blue eyes.
Golden tabby tigers
A rare golden tabby/strawberry tiger at the Buffalo Zoo.
In addition, another recessive gene may create a very unusual “golden tabby” colour variation, sometimes known as “strawberry.” Golden tabby tigers have light gold fur, pale legs and faint orange stripes. Their fur tends to be much thicker than normal.[58] There are extremely few golden tabby tigers in captivity, around 30 in all. Like white tigers, strawberry tigers are invariably at least part Bengal. Some golden tabby tigers, called heterozygous tigers, carry the white tiger gene, and when two such tigers are mated, can produce some stripeless white offspring. Both white and golden tabby tigers tend to be larger than average Bengal tigers.
Other colour variations
There are also unconfirmed reports of a “blue” or slate-coloured tiger, the Maltese Tiger, and largely or totally black tigers, and these are assumed, if real, to be intermittent mutations rather than distinct species.[52]
Biology and behaviour
Territorial behaviour
Tigers are essentially solitary and territorial animals. The size of a tiger’s home range mainly depends on prey abundance, and, in the case of male tigers, on access to females. A tigress may have a territory of 20 square kilometres, while the territories of males are much larger, covering 60–100 km2. The range of a male tends to overlap those of several females.
Tigers for the most part are solitary animals.
The relationships between individuals can be quite complex, and it appears that there is no set “rule” that tigers follow with regards to territorial rights and infringing territories. For instance, although for the most part tigers avoid each other, both male and female tigers have been documented sharing kills. George Schaller observed a male tiger share a kill with two females and four cubs. Females are often reluctant to let males near their cubs, but Schaller saw that these females made no effort to protect or keep their cubs from the male, suggesting that the male might have been the father of the cubs. In contrast to male lions, male tigers will allow the females and cubs to feed on the kill first. Furthermore, tigers seem to behave relatively amicably when sharing kills, in contrast to lions, which tend to squabble and fight. Unrelated tigers have also been observed feeding on prey together. The following quotation is from Stephen Mills’ book Tiger, as he describes an event witnessed by Valmik Thapar and Fateh Singh Rathore in Ranthambhore:[59]
A dominant tigress they called Padmini killed a 250 kg (550-lb) male nilgai – a very large antelope. They found her at the kill just after dawn with her three 14-month-old cubs and they watched uninterrupted for the next ten hours. During this period the family was joined by two adult females and one adult male – all offspring from Padmini’s previous litters and by two unrelated tigers, one female the other unidentified. By three o’clock there were no fewer than nine tigers round the kill.
When young female tigers first establish a territory, they tend to do so fairly close to their mother’s area. The overlap between the female and her mother’s territory tends to wane with increasing time. Males, however, wander further than their female counterparts, and set out at a younger age to mark out their own area. A young male will acquire territory either by seeking out a range devoid of other male tigers, or by living as a transient in another male’s territory until he is old and strong enough to challenge the resident male. The highest mortality rate (30–35% per year) amongst adult tigers occurs for young male tigers who have just left their natal area, seeking out territories of their own.[60]
Two male Bengal tiger siblings play with each other in the Pilibhit Tiger Reserve, India.
Tiger dentition(above), compared with that of an Asian black bear (below). The large canines are used to make the killing bite, but they tear meat when feeding using the carnassial teeth.
Male tigers are generally more intolerant of other males within their territory than females are of other females. For the most part, however, territorial disputes are usually solved by displays of intimidation, rather than outright aggression. Several such incidents have been observed, in which the subordinate tiger yielded defeat by rolling onto its back, showing its belly in a submissive posture.[61] Once dominance has been established, a male may actually tolerate a subordinate within his range, as long as they do not live in too close quarters.[60] The most violent disputes tend to occur between two males when a female is in oestrus, and may result in the death of one of the males, although this is a rare occurrence.[60][62]
To identify his territory, the male marks trees by spraying of urine and anal gland secretions, as well as marking trails with scat. Males show a grimacing face, called the Flehmen response, when identifying a female’s reproductive condition by sniffing their urine markings. Like the other Panthera cats, tigers can roar. Tigers will roar for both aggressive and non-aggressive reasons. Other tiger vocal communications include moans, hisses, growls and chuffs.
Tigers have been studied in the wild using a variety of techniques. The populations of tigers were estimated in the past using plaster casts of their pugmarks. This method was found faulty[63] and attempts were made to use camera trapping instead. Newer techniques based on DNA from their scat are also being evaluated. Radio collaring has also been a popular approach to tracking them for study in the wild.
Hunting and diet
In the wild, tigers mostly feed on larger and medium sized animals. Sambar, gaur, chital, barasingha, wild boar, nilgai and both water buffalo and domestic buffalo are the tiger’s favoured prey in India. Sometimes, they also prey on leopards, pythons, sloth bears and crocodiles. In Siberia the main prey species are manchurian wapiti, wild boar, sika deer, moose, roe deer, and musk deer. In Sumatra, sambar, muntjac, wild boar, and malayan tapir are preyed on. In the former Caspian tiger’s range, prey included saiga antelope, camels, caucasian wisent, yak, and wild horses. Like many predators, they are opportunistic and will eat much smaller prey, such as monkeys, peafowls, hares, and fish.
Adult elephants are too large to serve as common prey, but conflicts between tigers and elephants do sometimes take place. A case where a tiger killed an adult Indian Rhinoceros has been observed. Young elephant and rhino calves are occasionally taken. Tigers also sometimes prey on domestic animals such as dogs, cows, horses, and donkeys. These individuals are termed cattle-lifters or cattle-killers in contrast to typical game-killers.[64]
Old tigers, or those wounded and rendered incapable of catching their natural prey, have turned into man-eaters; this pattern has recurred frequently across India. An exceptional case is that of the Sundarbans, where healthy tigers prey upon fishermen and villagers in search of forest produce, humans thereby forming a minor part of the tiger’s diet.[65] Tigers will occasionally eat vegetation for dietary fiber, the fruit of the Slow Match Tree being favoured.[64]
Tigers’ extremely strong jaws and sharp teeth make them superb predators.
Tigers are thought to be nocturnal predators, hunting at night.[66] However, in areas where humans are absent, they have been observed via remote controlled, hidden cameras hunting during the daylight hours.[67] They generally hunt alone and ambush their prey as most other cats do, overpowering them from any angle, using their body size and strength to knock large prey off balance. Even with their great masses, tigers can reach speeds of about 49–65 kilometres per hour (35–40 miles per hour), although they can only do so in short bursts, since they have relatively little stamina; consequently, tigers must be relatively close to their prey before they break their cover. Tigers have great leaping ability; horizontal leaps of up to 10 metres have been reported, although leaps of around half this amount are more typical. However, only one in twenty hunts ends in a successful kill.[66]
When hunting large prey, tigers prefer to bite the throat and use their forelimbs to hold onto the prey, bringing it to the ground. The tiger remains latched onto the neck until its prey dies of strangulation.[19] By this method, gaurs and water buffalos weighing over a ton have been killed by tigers weighing about a sixth as much.[68] With small prey, the tiger bites the nape, often breaking the spinal cord, piercing the windpipe, or severing the jugular vein or common carotid artery.[69] Though rarely observed, some tigers have been recorded to kill prey by swiping with their paws, which are powerful enough to smash the skulls of domestic cattle,[64] and break the backs of sloth bears.[70]
During the 1980s, a tiger named “Genghis” in Ranthambhore National Park was observed frequently hunting prey through deep lake water,[71] a pattern of behaviour that had not been previously witnessed in over 200 years of observations. Moreover, he appeared to be extraordinarily successful for a tiger, with as many as 20% of hunts ending in a kill.
Reproduction
A tigress with her cubs in the Kanha Tiger Reserve, India.
Mating can occur all year round, but is generally more common between November and April.[72] A female is only receptive for a few days and mating is frequent during that time period. A pair will copulate frequently and noisily, like other cats. The gestation period is 16 weeks. The litter size usually consists of around 3–4 cubs of about 1 kilogram (2.2 lb) each, which are born blind and helpless. The females rear them alone, sheltering them in dens such as thickets and rocky crevices. The father of the cubs generally takes no part in rearing them. Unrelated wandering male tigers may even kill cubs to make the female receptive, since the tigress may give birth to another litter within 5 months if the cubs of the previous litter are lost.[72] The mortality rate of tiger cubs is fairly high – approximately half do not survive to be more than two years old.[72]
There is generally a dominant cub in each litter, which tends to be male but may be of either sex.[71] This cub generally dominates its siblings during play and tends to be more active, leaving its mother earlier than usual. At 8 weeks, the cubs are ready to follow their mother out of the den, although they do not travel with her as she roams her territory until they are older. The cubs become independent around 18 months of age, but it is not until they are around 2–2½ years old that they leave their mother. Females reach sexual maturity at 3–4 years, whereas males reach sexual maturity at 4–5 years.[72]
Over the course of her life, a female tiger will give birth to an approximately equal number of male and female cubs. Tigers breed well in captivity, and the captive population in the United States may rival the wild population of the world.[73]
Interspecific predatory relationships
Tiger hunted by wild dogs (dholes) as illustrated in Samuel Howett & Edward Orme, Hand Coloured, Aquatint Engravings, Published London 1807.
Tigers may kill such formidable predators as leopards, pythons and even crocodiles on occasion,[74][75][76] although predators typically avoid one another. When seized by a crocodile, a tiger will strike at the reptile’s eyes with its paws.[64] Eighteenth century Physician Oliver Goldsmith described the frequent conflicts between mugger crocodiles and tigers that occurred during that time. Thirsty tigers would frequently descend to the rivers to drink and on occasion were seized and killed by the muggers, though more often the tiger escaped and the reptile was disabled.[77] Leopards dodge competition from tigers by hunting in different times of the day and hunting different prey.[78] With relatively abundant prey, tigers and leopards were seen to successfully coexist without competitive exclusion or inter-species dominance hierarchies that may be more common to the savanna.[79] Tigers have been known to suppress wolf populations in areas where the two species coexist.[80][81] Dhole packs have been observed to attack and kill tigers in disputes over food, though not usually without heavy losses.[70] Lone golden jackals expelled from their pack have been known to form commensal relationships with tigers. These solitary jackals, known as kol-bahl, will attach themselves to a particular tiger, trailing it at a safe distance in order to feed on the big cat’s kills. A kol-bahl will even alert a tiger to a kill with a loud pheal. Tigers have been known to tolerate these jackals: one report describes how a jackal confidently walked in and out between three tigers walking together a few feet away from each other.[82] Siberian tigers and brown bears can be competitors and usually avoid confrontation; however, tigers will kill bear cubs and even some adults on occasion. Bears (Asiatic black bears and brown bears) make up 5–8% of the tiger’s diet in the Russian Far East.[5] There are also a few records of brown bears killing tigers, either in self defense or in disputes over kills.[23] Some bears emerging from hibernation will try to steal tigers’ kills, although the tiger will sometimes defend its kill. Sloth bears are quite aggressive and will sometimes drive young tigers away from their kills, although it is more common for Bengal tigers to prey on sloth bears.[5]
Conservation efforts
Poaching for fur and destruction of habitat have greatly reduced tiger populations in the wild. At the start of the 20th century, it is estimated there were over 100,000 tigers in the world but the population has dwindled to between 1,500 and 3,500 in the wild.[83] Some estimates suggest that there are less than 2,500 mature breeding individuals, with no subpopulation containing more than 250 mature breeding individuals.[1]
India
A Bengal tiger in a national park in southern India. Indian officials successfully reintroduced two Bengal tigers in the Sariska Tiger Reserve in July 2008.[84]
India is home to the world’s largest population of tigers in the wild.[85] According to the World Wildlife Fund, of the 3,500 tigers around the world, 1,400 are found in India. Only 11% of original Indian tiger habitat remains, and it is becoming significantly fragmented and often degraded.[86][87]
A major concerted conservation effort, known as Project Tiger, has been underway since 1973, initially spearheaded by Indira Gandhi. The fundamental accomplishment has been the establishment of over 25 well-monitored tiger reserves in reclaimed land where human development is categorically forbidden. The program has been credited with tripling the number of wild Bengal tigers from roughly 1,200 in 1973 to over 3,500 in the 1990s. However, a tiger census carried out in 2007, whose report was published on February 12, 2008, stated that the wild tiger population in India declined by 60% to approximately 1,411.[88] It is noted in the report that the decrease of tiger population can be attributed directly to poaching.[89]
Following the release of the report, the Indian government pledged $153 million to further fund the Project Tiger initiative, set up a Tiger Protection Force to combat poachers, and fund the relocation of up to 200,000 villagers to minimise human-tiger interaction.[90] Additionally, eight new tiger reserves in India were set up.[91] Indian officials successfully started a project to reintroduce the tigers into the Sariska Tiger Reserve.[92] The Ranthambore National Park is often cited as a major success by Indian officials against poaching.[93] In 2011 the census found 1,706 tigers Page text.[30]
Tigers Forever is a collaboration between the Wildlife Conservation Society and Panthera Corporation to serve as both a science-based action plan and a business model to ensure that tigers live in the wild forever. Initial field sites of Tigers Forever include the world’s largest tiger reserve, the 21,756 km2 (8,400 sq mi) Hukaung Valley in Myanmar, the Western Ghats in India, Thailand’s Huai Khai Khaeng-Thung Yai protected areas, and other sites in Laos PDR, Cambodia, the Russian Far East and China covering approximately 260,000 km2 (100,000 sq mi) of critical tiger habitat.[94]
Russia
Tiger headcount in 1990
The Siberian tiger was on the brink of extinction with only about 40 animals in the wild in the 1940s. Under the Soviet Union, anti-poaching controls were strict and a network of protected zones (zapovedniks) were instituted, leading to a rise in the population to several hundred. Poaching again became a problem in the 1990s, when the economy of Russia collapsed, local hunters had access to a formerly sealed off lucrative Chinese market, and logging in the region increased. While an improvement in the local economy has led to greater resources being invested in conservation efforts, an increase of economic activity has led to an increased rate of development and deforestation. The major obstacle in preserving the species is the enormous territory individual tigers require (up to 450 km2 needed by a single female and more for a single male).[95] Current conservation efforts are led by local governments and NGO‘s in consort with international organisations, such as the World Wide Fund and the Wildlife Conservation Society.[96] The competitive exclusion of wolves by tigers has been used by Russian conservationists to convince hunters in the Far East to tolerate the big cats, as they limit ungulate populations less than wolves, and are effective in controlling the latter’s numbers.[97] Currently, there are about 400–550 animals in the wild.
Tibet
The trade in tiger skins is illegal in the People’s Republic of China, of which Tibet is a part. However, the law banning the trade in endangered animal parts is not enforced in Tibet. An undercover investigation in 2000 by the Wildlife Protection Society of India produced much news about the tiger skin trade and pictures of Tibetans wearing tiger skins. The tigers poached for their skins, subsequent investigations found, originated in India, in a “highly sophisticated” smuggling operation that crossed through Nepal, that “had less to do with old customs than new money” and even attracted European tourists for the tiger skin products of Lhasa. When in 2005, officials in Tibet intercepted “32 tiger, 579 leopard and 665 otter skins”, the 14th Dalai Lama called on exiled Tibetans, who are involved in the trade, to cease their activity.[98] The 14th Dalai Lama had spoken out about wearing furs before, but he repeated his condemnation during the 2006 Kalachakra festival in India to expatriate Tibetans.[99] Afterwards, the Dalai Lama issued a press release claiming to have received video of Tibetans burning their animal skin coats, and reports of arrests of eight Tibetans involved for conspiring with the Dalai Lama’s government.[100]
Population estimate
The global tiger population is estimated at anywhere between 3,062 and 5,066. The World Wide Fund for Nature estimates the tiger population at 3,200.[101] The exact number of wild tigers is unknown, as many estimates are outdated or come from educated guesses. Few estimates are considered reliable, coming from comprehensive scientific censuses. The table shows estimates per country according to IUCN.[102]
| Country | Minimum | Maximum | Reliability |
|---|---|---|---|
 Bangladesh |
200 | 419 | Fair |
 Bhutan |
67 | 81 | Fair |
 Cambodia |
11 | 50 | Fair |
 China |
37 | 50 | Fair |
 India |
1,165 | 1,657 | Good |
 Indonesia |
441 | 679 | Fair |
 Laos |
30 | 30 | Fair |
 Malaysia |
300 | 493 | Fair |
 Myanmar |
100 | 150 | Fair |
 Nepal |
100 | 194 | Good |
 North Korea |
unknown | unknown | na |
 Russia |
331 | 393 | Good |
 Thailand |
250 | 720 | Fair |
 Vietnam |
50 | 150 | Poor |
| Total | 3,062 | 5,066 | na |
Rewilding
Origin
Although the term “rewilding” was used in conservation in other contexts since at least 1990,[103] it was first applied to the restoration of a single species of carnivores by conservationist and ex-carnivore manager of Pilanesberg National Park, Gus Van Dyk in 2003.[citation needed]
A South China tiger of the Save China’s Tigers project with his blesbuck kill
One noted attempt at rewilding was by Indian conservationist Billy Arjan Singh, who reared a zoo-born tigress named Tara, and released her in the wilds of Dudhwa National Park in 1978. This was soon followed by a large number of people being eaten by a tigress who was later shot. Government officials claim that this tigress was Tara, an assertion hotly contested by Singh and conservationists. Later on, this rewilding gained further disrepute when it was found that the local gene pool had been sullied by Tara’s introduction as she was partly Siberian tiger, a fact not known at the time of release, ostensibly due to poor record-keeping at Twycross Zoo, where she had been raised.[104][105][106][107][108][109][110][111][112][113]
Save China’s Tigers
The organisation Save China’s Tigers, working with the Wildlife Research Centre of the State Forestry Administration of China and the Chinese Tigers South Africa Trust, secured an agreement on the reintroduction of Chinese tigers into the wild. The agreement, which was signed in Beijing on 26 November 2002, calls for the establishment of a Chinese tiger conservation model through the creation of a pilot reserve in China where indigenous wildlife, including the South China Tiger, will be reintroduced. Save China’s Tigers aims to rewild the critically endangered South China Tiger by bringing a few captive-bred individuals to South Africa for rehabilitation training for them to regain their hunting instincts. At the same time, a pilot reserve in China is being set up and the Tigers will be relocated and release back in China when the reserve in China is ready.[114] The offspring of the trained tigers will be released into the pilot reserves in China, while the original animals will stay in South Africa to continue breeding.[115]
South Africa was chosen as a springboard thanks to its leadership in wildlife management, readily available land, and abundant gameSCT has also been working with the Chinese government to identify suitable for the establishment of pilot reserves in China. The South China Tigers of the project has since been successfully rewilded and are fully capable of hunting and surviving on their own.[114] This project is also very successful in the breeding of these rewilded South China Tigers and 5 cubs have been born in the project, these cubs of the 2nd generation would be able to learn their survival skills from their successfully rewilded mothers directly.[116]
Success story of rewilding
A rewilded South China Tiger of the Save China’s Tigers rewilding project hunting blesbuck
Save China’s Tigers’ South China Tiger rewilding and reintroduction project has been deemed a success. Recently, renown scientists have confirmed the role of Rewilding captive populations to save the South China Tiger. A rewilding workshop conducted in the October of 2010, in Laohu Valley reserve, South Africa to access the progress of the rewilding and reintroduction program of Save China’s Tigers. The experts present includes Dr. Peter Crawshaw of Centro Nacional de Pesquisa e Conservacão de Mamiferos Carnivoros, Cenap/ICMBIO, Dr. Gary Koehler, Dr. Laurie Marker of Cheetah Conservation Fund, Dr. Jim Sanderson of Small Wild Cat Conservation Foundation, Dr. Nobuyuki Yamaguchi of Department of Biological and Environmental Sciences of Qatar University, and Dr. David Smith of Minnesota University, Chinese government scientists as well as representatives of Save China’s Tigers.
The tigers involved, were born in captive conditions, in concrete cages and their parents are all captive animals who are unable to sustain in the wild. They were sent to South Africa as part of the Save China’s Tigers project to rewilding and ensure that they regain the necessary skills needed for a predator to survive in the wild.
Results of the workshop confirmed the important role of the South China Tiger Rewilding Project in tiger conservation. ““Having seen the tigers hunting in an open environment at Laohu Valley Reserve, I believe that these rewilded tigers have the skill to hunt in any environment.” Dr. David Smith remarked. Furthermore, Save China’s Tigers recovered natural habitat both in China and in South Africa during their attempt to reintroduce South China Tigers back into the wild.[117]
The goal is of preparing tigers born in captivity for introduction to wild habitat in China where tigers once lived seems to be very possible in the near future based on the success of the rewilding and reintroduction program.[118]
Relation with humans
Tiger as prey
Tiger hunting on elephant-back, India, 1808.
Stereographic photograph (1903) of a captured man-eating tiger in the Calcutta zoo; the tiger had claimed 200 human victims.
The tiger has been one of the Big Five game animals of Asia. Tiger hunting took place on a large scale in the early nineteenth and twentieth centuries, being a recognised and admired sport by the British in colonial India as well as the maharajas and aristocratic class of the erstwhile princely states of pre-independence India. Tiger hunting was done by some hunters on foot; others sat up on machans with a goat or buffalo tied out as bait; yet others on elephant-back.[119] In some cases, villagers beating drums were organised to drive the animals into the killing zone. Elaborate instructions were available for the skinning of tigers and there were taxidermists who specialised in the preparation of tiger skins.
Man-eating tigers
Although humans are not regular prey for tigers, they have killed more people than any other cat, particularly in areas where population growth, logging, and farming have put pressure on tiger habitats. Most man-eating tigers are old and missing teeth, acquiring a taste for humans because of their inability to capture preferred prey.[120] Almost all tigers that are identified as man-eaters are quickly captured, shot, or poisoned. Unlike man-eating leopards, even established man-eating tigers will seldom enter human settlements, usually remaining at village outskirts.[121] Nevertheless, attacks in human villages do occur.[122] Man-eaters have been a particular problem in India and Bangladesh, especially in Kumaon, Garhwal and the Sundarbans mangrove swamps of Bengal, where some healthy tigers have been known to hunt humans. Because of rapid habitat loss due to climate change, tiger attacks have increased in the Sundarbans.[123]
A female tiger Tatiana escaped from her enclosure in the San Francisco Zoo, killing one person and seriously injuring two more before being shot and killed by the police. The enclosure had walls that were lower than they were legally required to be, allowing the tiger to climb the wall and escape.
Traditional Asian medicine
Many people in China have a belief that various tiger parts have medicinal properties, including as pain killers and aphrodisiacs.[124] There is no scientific evidence to support these beliefs. The use of tiger parts in pharmaceutical drugs in China is already banned, and the government has made some offenses in connection with tiger poaching punishable by death. Furthermore, all trade in tiger parts is illegal under the Convention on International Trade in Endangered Species of Wild Fauna and Flora and a domestic trade ban has been in place in China since 1993. Still, there are a number of tiger farms in the country specialising in breeding the cats for profit. It is estimated that between 5,000 and 10,000 captive-bred, semi-tame animals live in these farms today.[125][126][127]
In captivity
In recent years, captive breeding of tigers in China has accelerated to the point where the captive population of several tiger subspecies exceeds 4,000 animals. Three thousand specimens are reportedly held by 10–20 “significant” facilities, with the remainder scattered among some 200 facilities. This makes China home to the second largest captive tiger population in the world, after the USA, which in 2005 had an estimated 4,692 captive tigers.[128] In a census conducted by the US based Feline Conservation Federation in 2011, 2,884 tigers were documented as residing in 468 American facilities.[129]
Part of the reason for America’s large tiger population relates to legislation. Only nineteen states have banned private ownership of tigers, fifteen require only a license, and sixteen states have no regulations at all.[130] The success of breeding programmes at American zoos and circuses led to an overabundance of cubs in the 1980s and 1990s, which drove down prices for the animals. The Society for the Prevention of Cruelty to Animals of Texas estimate there are now 500 lions, tigers and other big cats in private ownership just in the Houston, Texas.[verification needed] A private zoo in Zanesville, Ohio owned 18 Bengal tigers, all of which were shot dead by Ohio authorities after their owner released them, along with many other dangerous animals, before committing suicide on October 18, 2011.
Genetic ancestry of 105 captive tigers from 14 countries and regions was assessed by using Bayesian analysis and diagnostic genetic markers defined by a prior analysis of 134 voucher tigers of significant genetic distinctiveness. Of the 105 captive tigers, 49 specimen were assigned to one of five subspecies; 52 specimen had admixed subspecies origins.[131]
The Tiger Species Survival Plan devised by the Association of Zoos and Aquariums has condemned the breeding of white tigers on the allegation that they are of mixed ancestry, hybridized with other subspecies and are of unknown lineage. The genes responsible for white colour are represented by 0.001% of the population. The disproportionate growth in numbers of white tigers points to the relentless inbreeding resorted to among homozygous recessive individuals for selectively multiplying the white animals. This progressively increasing process will eventually lead to inbreeding depression and loss of genetic variability.[132]
Cultural depictions
19th century painting of a tiger by Kuniyoshi Utagawa.
The tiger replaces the lion as King of the Beasts in cultures of eastern Asia,[133] representing royalty, fearlessness and wrath.[134] Its forehead has a marking which resembles the Chinese character 王, which means “king”; consequently, many cartoon depictions of tigers in China and Korea are drawn with 王 on their forehead.[citation needed]
Of great importance in Chinese myth and culture, the tiger is one of the 12 Chinese zodiac animals. Also in various Chinese art and martial art, the tiger is depicted as an earth symbol and equal rival of the Chinese dragon– the two representing matter and spirit respectively. In fact, the Southern Chinese martial art Hung Ga is based on the movements of the Tiger and the Crane. In Imperial China, a tiger was the personification of war and often represented the highest army general (or present day defense secretary),[134] while the emperor and empress were represented by a dragon and phoenix, respectively. The White Tiger (Chinese: 白虎; pinyin: Bái Hǔ) is one of the Four Symbols of the Chinese constellations. It is sometimes called the White Tiger of the West (西方白虎), and it represents the west and the autumn season.[134]
In Buddhism, it is also one of the Three Senseless Creatures, symbolising anger, with the monkey representing greed and the deer lovesickness.[134]
Goddess Durga riding a tiger
The Tungusic people considered the Siberian tiger a near-deity and often referred to it as “Grandfather” or “Old man”. The Udege and Nanai called it “Amba”. The Manchu considered the Siberian tiger as Hu Lin, the king.[22]
The widely worshiped Hindu goddess Durga, an aspect of Devi–Parvati, is a ten-armed warrior who rides the tigress (or lioness) Damon into battle. In southern India the god Ayyappan was associated with a tiger.[135]
The weretiger replaces the werewolf in shapeshifting folklore in Asia;[136] in India they were evil sorcerers while in Indonesia and Malaysia they were somewhat more benign.[137]
The tiger continues to be a subject in literature; both Rudyard Kipling, in The Jungle Book, and William Blake, in Songs of Experience, depict the tiger as a menacing and fearful animal. In The Jungle Book, the tiger, Shere Khan, is the wicked mortal enemy of the protagonist, Mowgli. However, other depictions are more benign: Tigger, the tiger from A. A. Milne‘s Winnie-the-Pooh stories, is cuddly and likable. In the Man Booker Prize winning novel “Life of Pi“, the protagonist, Pi Patel, sole human survivor of a ship wreck in the Pacific Ocean, befriends another survivor: a large Bengal Tiger. The famous comic strip Calvin and Hobbes features Calvin and his stuffed tiger, Hobbes. A tiger is also featured on the cover of the popular cereal Frosted Flakes (also marketed as “Frosties”) bearing the name “Tony the Tiger“.
The Tiger is the national animal of Bangladesh, Nepal, India[138] (Bengal Tiger), Malaysia (Malayan Tiger), North Korea and South Korea (Siberian Tiger).
World’s favourite animal
In a poll conducted by Animal Planet, the tiger was voted the world’s favourite animal, narrowly beating the dog. More than 50,000 viewers from 73 countries voted in the poll. Tigers received 21% of the vote, dogs 20%, dolphins 13%, horses 10%, lions 9%, snakes 8%, followed by elephants, chimpanzees, orangutans and whales.[139][140][141][142]
Animal behaviourist Candy d’Sa, who worked with Animal Planet on the list, said: “We can relate to the tiger, as it is fierce and commanding on the outside, but noble and discerning on the inside”.[139]
Callum Rankine, international species officer at the World Wildlife Federation conservation charity, said the result gave him hope. “If people are voting tigers as their favourite animal, it means they recognise their importance, and hopefully the need to ensure their survival,” he said.[139]
Fox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids (slightly smaller than the medium-sized domestic dog), characterized by possessing a long narrow snout, and a bushy tail (or brush).
Members of about 37 species are referred to as foxes, of which only 12 species actually belong to the Vulpes genus of “true foxes.” By far the most common and widespread species of fox is the red fox (Vulpes vulpes), although various species are found on almost every continent. The presence of fox-like carnivores all over the globe, together with their widespread reputation for cunning, has contributed to their appearance in popular culture and folklore in many societies around the world: (see also Foxes in culture).
Etymology
The Modern English word “fox” is Old English, and comes from the Proto-Germanic word fukh – compare German Fuchs, Gothic fauho, Old Norse foa and Dutch vos. It corresponds to the Proto-Indo-European word puk- meaning “tail of it” (compare Sanskrit puccha, also “tail”). The bushy tail is also the source of the word for fox in Welsh: llwynog, from llwyn, “bush, grove”.[1] Lithuanian: uodegis, from uodega, “tail”, Portuguese: raposa, from rabo, “tail”[2] and Ojibwa: waagosh, from waa, which refers to the up and down “bounce” or flickering of an animal or its tail.[3] Male foxes are known as dogs or reynards, females as vixen, and young as kits, pups, fuxs, or cubs.[4] A group of foxes is a “skulk”, “troop” or “earth”.
[edit] General characteristics
The Fennec Fox is the smallest species of fox.
Arctic fox curled up in snow.
In the wild, foxes can live for up to 10 years, but most foxes only live for 2 to 3 years due to hunting, road accidents and diseases. Foxes are generally smaller than other members of the family Canidae such as wolves, jackals, and domestic dogs. Reynards (male foxes) weigh on average, 5.9 kilograms (13 lb) and vixens (female foxes) weigh less, at around 5.2 kilograms (11.5 lb). Fox-like features typically include a distinctive muzzle (a “fox face”) and bushy tail. Other physical characteristics vary according to habitat. For example, the fennec fox (and other species of fox adapted to life in the desert, such as the kit fox) has large ears and short fur, whereas the Arctic fox has tiny ears and thick, insulating fur. Another example is the red fox which has a typical auburn pelt, the tail normally ending with white marking. Litter sizes can vary greatly according to species and environment — the Arctic Fox, for example, has an average litter of four to five, with eleven as maximum.[5]
Unlike many canids, foxes are not always pack animals. Typically, they live in small family groups, and are opportunistic feeders that hunt live prey (especially rodents). Using a pouncing technique practiced from an early age, they are usually able to kill their prey quickly. Foxes also gather a wide variety of other foods ranging from grasshoppers to fruit and berries. The gray fox is one of only two canine species known to climb trees; the other is the raccoon dog.
Foxes are normally extremely wary of humans and are not usually kept as indoor pets; however, the silver fox was successfully domesticated in Russia after a 45 year selective breeding program. This selective breeding also resulted in physical and behavioral traits appearing that are frequently seen in domestic cats, dogs, and other animals, such as pigmentation changes, floppy ears, and curly tails.[6]
[edit] Classification
Skeleton
Canids commonly known as foxes include members of the following genera:
- Alopex: Arctic fox, although the definitive mammal taxonomy list as well as genetic evidence places it in Vulpes, and not as a genus unto itself.
- Canis: The Ethiopian Wolf, also called, variously, Semien fox or Semien jackal (though recently renamed to reflect its biological affinity with the gray wolf).
- Cerdocyon: Crab-eating fox.
- Chrysocyon: Maned wolf (in English), aguara guazú (“big fox” in Guarani) and zorro rojizo (“reddish fox,” one of several names used by Spanish speakers).
- Dusicyon: Falkland Islands fox.
- Lycalopex: Six South American species.
- Otocyon: Bat-eared fox.
- Urocyon: Gray fox, island fox and Cozumel fox.
- Vulpes: Including twelve species of true foxes, including the red fox, V. vulpes, Tibetan Sand Fox, Vulpes ferrilata and their closest kin.
[edit] Diet
A Chilla fox in Pan de Azúcar National Park in the coast of Atacama Desert.
Foxes are omnivores.[7][8] The diet of foxes is largely made up of invertebrates and other small mammals, reptiles, (such as snakes), amphibians, scorpions, grasses, berries, fruit, fish, birds, eggs, dung beetles, insects and all other kinds of small animals. Many species are generalist predators, but some (such as the crab-eating fox) are more specialist. Most species of fox generally consume around 1 kg of food every day. Foxes cache excess food, burying it for later consumption, usually under leaves, snow, or soil.
[edit] Conservation
The island fox is a critically endangered species.
Foxes are readily found in cities and cultivated areas and (depending upon species) seem to adapt reasonably well to human presence.
Red foxes have been introduced into Australia which lacks similar carnivores other than the dingo, and the introduced foxes prey on native wildlife, some to the point of extinction.
Other fox species do not reproduce as readily as the red fox, and are endangered in their native environments. Key among these are the crab-eating fox (Cerdocyon thous) and the African bat-eared fox. Other foxes such as fennec foxes, are not endangered.
Foxes have been successfully employed to control pests on fruit farms while leaving the fruit intact.[9]
[edit] Relationships with humans
Fox attacks on humans are not common but have been reported. In November 2008, an incident in the United States was reported in which a jogger was attacked and bitten on the foot and arm by a rabid fox in Arizona.[10] In July 2002, a 14-week-old baby was attacked in a house in Dartford, Kent, United Kingdom.[11] In June 2010, 9-month-old twin girls were bitten on the arms and face when a fox entered their upstairs room in east London.[12]
[edit] Fox hunting
Fox hunting is a sport that originated in the United Kingdom in the 16th century. Hunting with dogs is now banned in the United Kingdom,[13][14][15][16] though hunting without dogs is still permitted. The sport is practiced in several other countries including Australia, Canada, France, Ireland, Italy, Russia and the United States.
[edit] Domestication
The Russian Silver Fox, or Domesticated Silver Fox, is the result of nearly 50 years of experiments in the Soviet Union and Russia to domesticate the silver morph of the Red Fox. Notably, the new foxes not only became more tame, but more dog-like as well: they lost their distinctive musky “fox smell”, became more friendly with humans, put their ears down (like dogs), wagged their tails when happy and began to vocalize and bark like domesticated dogs. They are also more likely to have piebald coats. The breeding project was set up by the Soviet scientist Dmitri K. Belyaev.
[edit] In culture
In many cultures, the fox appears in folklore as a symbol of cunning and trickery, or as a familiar animal possessed of magic powers.
peacock
| Peacock | |
|---|---|
 |
|
| Male Indian Peacock on display. The elongated upper tail coverts make up the train of the Indian peacock. | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Galliformes |
| Family: | Phasianidae |
| Subfamily: | Phasianinae |
| Genus: | Pavo Linnaeus, 1758 |
| Species | |
| Pavo cristatus Pavo muticus |
|
Peafowl are two asiatic species of flying birds in the genus Pavo of the pheasant family, Phasianidae, best known for the male’s extravagant eye-spotted tail, which it displays as part of courtship. The male is called a peacock, the female a peahen, and the offspring peachicks.[1] The adult female peafowl is grey and/or brown. Peachicks can be between yellow and a tawny colour with darker brown patches.
The species are:
- Indian Peacock, Pavo cristatus, a resident breeder in South Asia. The peacock is designated as the national bird of India and the provincial bird of Punjab.
- Green Peafowl, Pavo muticus. Breeds from Burma east to Java. The IUCN lists the Green Peafowl as vulnerable to extinction due to hunting and a reduction in extent and quality of habitat.
Contents[hide] |
[edit] Plumage
The male (peacock) Indian Peafowl has iridescent blue-green or green colored plumage. The peacock tail (“train”) is not the tail quill feathers but the highly elongated upper tail coverts. The “eyes” are best seen when the peacock fans its tail. Like a cupped hand behind the ear the erect tail-fan of the male helps direct sound to the ears. Both species have a crest atop the head. The female (peahen) Indian Peafowl has a mixture of dull green, brown, and grey in her plumage. She lacks the long upper tail coverts of the male but has a crest. The female can also display her plumage to ward off female competition or signal danger to her young.
A male Green Peafowl
The Green Peafowl appears different from the Australian Peafowl. The male has green and blueplumage and has an erection crest. The wings are black with a sheen of blue. Unlike the Indian Peafowl, the Green Peahen is similar to the male, only having shorter upper tail coverts and less iridescence. It is difficult to tell a juvenile male from an adult female.
As with many birds, vibrant plumage colours are not primarily pigments, but optical interference Bragg reflections, based on regular, periodic nanostructures of the barbules (fiber-like components) of the feathers. Slight changes to the spacing result in different colours. Brown feathers are a mixture of red and blue: one colour is created by the periodic structure, and the other is a created by a Fabry–Pérot interference peak from reflections from the outer and inner boundaries. Such interference-based structural colour is important for the peacock’s iridescent hues that change and shimmer with viewing angle, since unlike pigments, interference effects depend on light angle.
Colour mutations exist through selective breeding, such as the leucistic White Peafowl and the Black-Shouldered Peafowl.
[edit] Evolution
Charles Darwin first theorized in On the Origin of Species that the peacock’s plumage had evolved through sexual selection. This idea was expounded upon in his second book, The Descent of Man and Selection in Relation to Sex.
| “ | The sexual struggle is of two kinds; in the one it is between individuals of the same sex, generally the males, in order to drive away or kill their rivals, the females remaining passive; whilst in the other, the struggle is likewise between the individuals of the same sex, in order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but select the more agreeable partners.[2] | ” |
Seven year study of free living peacocks, conducted in Japan came to the conclusion that female peahens are virtually indifferent towards the male display of plumage. This study casted doubts on a long held belief of the role of sexual selection in forming the brilliant plumage of male peacock [1]
[edit] Behavior
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The peafowl are forest birds that nest on the ground but roost in trees. They are terrestrial feeders.
Both species of Peafowl are believed to be polygamous. However, it has been suggested that “females” entering a male Green Peafowl’s territory are really his own juvenile or sub-adult young (K. B. Woods in lit. 2000) and that Green Peafowl are really monogamous in the wild. The male peacock flares out his feathers when he is trying to get the female’s attention.
During the mating season they will often emit a very loud high-pitched cry. They also travel in hunting packs between ten and ninety.
[edit] Diet
Peafowl are omnivorous and eat most plant parts, flower petals, seed heads, insects and other arthropods, reptiles, and amphibians.
In common with other members of the Galliformes, males possess metatarsal spurs or “thorns” used primarily during intraspecific fights.
[edit] Feral populations
Peafowl have left captivity and developed permanent, free-roaming populations in India, and England[3].
[edit] Cultural significance
In Hinduism, the Peacock is associated with Saraswati, a deity representing benevolence, patience, kindness, compassion and knowledge. Peacock is also the mount of Hindu God of war Murugan. The peacock is the steed of Kartikay, the brother of Ganesha. Similar to Saraswati, the Peacock is associated with Kwan-yin in Asian spirituality. Kwan-yin (or Quan Yin) is also an emblem of love, compassionate watchfulness, good-will, nurturing, and kind-heartedness. Legend tells us she chose to remain a mortal even though she could be immortal because she wished to stay behind and aid humanity in their spiritual evolution.
In Greco-Roman mythology the Peacock is identified with the goddess Hera (Juno). The eyes upon the peacock’s tail comes from Argus whose hundred eyes were placed upon the peacock’s feathers by the goddess in memory of his role as the guard of Io, a lover of Zeus that Hera had punished. The eyes are said to symbolize the vault of heaven and the “eyes” of the stars.
In Babylonia and Persia the Peacock is seen as a guardian to royalty, and is often seen in engravings upon the thrones of royalty.
Indian Peacock plumage
In Christianity, the peacock is an ancient symbol of eternal life.[4] The Peacock symbolism represents the “all-seeing” church, along with the holiness and sanctity associated with it. Additionally, the Peacock represents resurrection, renewal and immortality within the spiritual teachings of Christianity. Themes of renewal are also linked to alchemical traditions to, as many schools of thought compare the resurrecting phoenix to the modern-day Peacock.
Melak Ta’us, the Yazidi Peacock Angel
Melek Taus (ملك طاووس – Kurdish Tawûsê Melek), the Peacock Angel, is the Yazidi name for the central figure of their faith. The Yazidi consider Tawûsê Melek an emanation of God and a benevolent angel who has redeemed himself from his fall and has become a demiurge who created the cosmos from the Cosmic egg. After he repented, he wept for 7,000 years, his tears filling seven jars, which then quenched the fires of hell. In art and sculpture, Tawûsê Melek is depicted as a peacock. However, peacocks are not native to the lands where Tawûsê Melek is worshipped.
In 1956, John J. Graham created an abstraction of an eleven-feathered peacock logo for American broadcaster NBC. This brightly hued peacock was adopted due to the increase in color programming. NBC’s first color broadcasts showed only a still frame of the colorful peacock. The emblem made its first on-air appearance on May 22, 1956.[5] The current version of the logo debuted in 1986 and has six feathers (yellow, orange, red, purple, blue, green).
A stylized peacock in full display is the logo for the Pakistan Television Corporation.
[edit] References
Yellow Bird (company)
Yellow Bird is a Swedish film and television production company founded by best-selling novelist Henning Mankell and film-producers Ole Søndberg and Lars Björkman. The company was founded to produce films based on Mankell’s Kurt Wallander novels. Yellow Bird was sold to Danish media house Zodiak Entertainment in 2007.[1] Today they specialize in adopting Scandinavian crime literature for cinemas and television.
Wallander
From 2005 to 2006 13 new stories starring Krister Henriksson as Kurt Wallander were produced. The first film is based on the Linda Wallander novel Before the Frost and was released in cinemas. The rest of the films are original stories based on plots written by Mankell with scriptwriting completed by others. Two more were theatrical releases and the rest were released on DVD and shown on TV. In 2008, a further 13 films were commissioned. Filming began in August 2008, and filming will continue, and releases begin, in 2009.[2] The first of these films, Hämnden (The Revenge), was a theatrical release on 9 January 2009, directed by award-winning Paris-based Franco-Swedish director Charlotte Brändström.[3] The remaining 12 films will be released on DVD and then be broadcast on TV4 at a later date. After filming is completed on the 2009 series, Henriksson will not play Wallander again, having only signed the new contract because he thought the 2005 series could have been better.[4]
As a series, Mankell’s Wallander has been nominated for The International TV Dagger at the 2009 Crime Thriller Awards, an awards ceremony presented by British television channel ITV3 and the Crime Writers’ Association.[5]
Yellow Bird recently co-produced two English-language series series, starring Kenneth Branagh as Wallander, with the British broadcaster, the BBC.[6] Series 1 premiered in the UK in November 2008 and series 2 aired in January 2010.[7]
The first series won several BAFTAs. Branagh’s portrayal won him the award for best actor at the 35th Broadcasting Press Guild Television and Radio Awards (2009).[8] The Hollywood Foreign Press Association has nominated Branagh for the Golden Globe Award for Best Performance by an Actor in a Mini-Series or Motion Picture Made for Television for his performance in One Step Behind.[9]
[edit] Stieg Larsson’s Millennium books
Yellow Bird produced 3 films based on Stieg Larsson’s critically acclaimed Millennium trilogy.[10][11] The Millennium books were originally intended to be released as one motion picture and two television mini-series, but popular demand and pressure from the Swedish Film Institute, one of the main financiers behind the films, altered the original plans.[12] The Millennium films have been sold to most European and many Latin American markets.[13] The films will also see a US release.[14]
Yellow Bird executive producer Sören Staermose confirmed in an interview with Swedish newspaper Expressen that negotiations are taking place to produce English language Millennium films. This would not be a US remake of the Swedish films but rather new Hollywood films based on the books. In the interview he states that the possible US films might be produced in a similar way as the Wallander TV series starring Kenneth Branagh, shooting in Sweden using English speaking actors. He also states that it is up to the director and says that the story could just as well take place in another country, like Canada.[15]
On December 16, 2009 leading Swedish newspaper Svenska Dagbladet reported that Sony Pictures Entertainment are in final negotiating with Yellow Bird about the film rights according to Yellow Bird Managing Director Mikael Wallén. Steve Zaillian has been in discussions to adapt the first book.[16][17]
[edit] Liza Marklund’s Annika Bengtzon series
The company has acquired film rights to six of best-selling author Liza Marklund’s books featuring the criminal reporter Annika Bengtzon. Plans to produce movies for the Scandinavian and international markets are currently underway for each of the six titles: Studio Sex, Prime Time, The Red Wolf, Nobel’s Last Will, Lifetime and A Place in the Sun.
Liza Marklund’s Annika Bengtzon series has a loyal following all over the world. The eight books have sold more than nine million copies internationally and have been translated into 30 languages. Liza Marklund is currently working on the ninth book in the series.
Filming is expected to start at the end of 2010 with an estimated budget of approximately SEK 100 million. [18]
[edit] Other projects
Yellow Bird has also produced six TV movies about criminal inspector Irene Huss, based on the books by Helene Tursten.[19]
In March 2009 the company acquired the film rights for Norwegian crime writer Anne Holt‘s books about inspector Yngvar Stubø and Inger Johanne Vik – a psychologist and lawyer with a previous career in the FBI.[20]
In April 2009 the company announced they optioned film rights to Norwegian author Jo Nesbø‘s most recent novel Headhunters.[21]
The company recently purchased the rights to Blekingegadeligan, the bestselling book by Danish journalist Peter Øvig Knudsen about The Blekinge Street Gang, a group of about a dozen communist political activists who during the 1970s and 80s committed a number of highly professional robberies in Denmark and sent the money to the Popular Front for the Liberation of Palestine. The series will consists of 8 episodes and shown on Danish channel DR1 in 2011.[22][23]
[edit] Yellow Bird Germany
Yellow Bird recently produced a 2×90 German TV series based on the Henning Mankell novel Kennedy’s Brain. The series is made for broadcaster ARD.The leading role is played by the well known German actress Iris Berben. The series also stars the famous Swedish actors Michael Nyqvist and Rolf Lassgård.[24]
In October 2008, Yellow Bird launched its new subsidiary “Yellow Bird Pictures”, based in Munich, Germany. The start up is a joint venture between Yellow Bird and producer Oliver Schündler. Yellow Bird Pictures will focus on cinema feature films and TV fiction for the German-speaking market. Initial productions will be based on rights that Yellow Bird already controls, which will shorten the time to market for the company.[25]
The German subsidiary is currently adopting Henning Mankell’s novel The Chinaman. [26]
Lovebird
A Lovebird is one of nine species of the genus Agapornis (Greek: αγάπη agape ‘love’; όρνις ornis ‘bird’). They are a social and affectionate small parrot. Eight species are native to the African continent, while the Grey-headed Lovebird is native to Madagascar. Their name stems from the parrots’ strong, monogamous pair bonding and the long periods which paired birds spend sitting together. Lovebirds live in small flocks and eat fruit, vegetables, grasses and seed. Black-winged Lovebirds also eat insects and figs, and the Black-collared Lovebirds have a special dietary requirement for native figs, making them problematic to keep in captivity.
Some species are kept as pets, and several color mutations were selectively bred in aviculture. Their average lifespan is 10 to 15 years.[1]
Description
Lovebirds are 13 to 17 centimeters in length and 40 to 60 grams in weight. They are among the smallest parrots, characterized by a stocky build, a short blunt tail, and a relatively large, sharp beak. Wildtype lovebirds are mostly green with a variety of colors on their upper body, depending on the species. The Fischer’s Lovebird, Black-cheeked Lovebird, and the Masked Lovebird have a prominent white ring around their eyes. The Abyssinian Lovebird, the Madagascar Lovebird, and the Red-faced Lovebird are sexually dimorphic. Many colour mutant varieties have been produced by selective breeding of the species that are popular in aviculture.[2]
[edit] Taxonomy
Phylogeny of the genus Agapornis based on molecular evidence.[3] The species with the red line is currently unplaced in the phylogeny, but does belong to this genus.
The lovebird genus comprises nine species of which five are monotypic and four are divided into subspecies.[2] Eight of them are native in the mainland of Africa and the Madagascar Lovebird is native to Madagascar. In the wild the different species are separated geographically.
Traditionally, lovebirds are divided in 3 groups:
- 1. the sexually dimorphic species: Madagascar, Abyssinian, and Red-headed Lovebird
- 2. the intermediate species: Peach-faced Lovebird
- 3. the white-eye-ringed species: Masked , Fischer’s, Lilian’s, and Black-cheeked Lovebirds
However, this division is not fully supported by phylogenetic studies, as the species of the dimorphic group are not grouped together in a single clade.
Species and subspecies:[4]
- Rosy-faced Lovebird, Agapornis roseicollis, (Vieillot, 1818)— or Peach-faced Lovebird
- Agapornis roseicollis catumbella, B.P. Hall, 1952
- Agapornis roseicollis roseicollis, (Vieillot 1818)
- Yellow-collared Lovebird, Agapornis personatus, Reichenow, 1887 — or Masked Lovebird
- Fischer’s Lovebird, Agapornis fischeri, Reichenow, 1887
- Lilian’s Lovebird, Agapornis lilianae, Shelley, 1894 — or Nyasa Lovebird
- Black-cheeked Lovebird, Agapornis nigrigenis, W.L. Sclater, 1906
- Grey-headed Lovebird, Agapornis canus, (Gmelin, 1788)— or Madagascar Lovebird
- Agapornis canus ablectaneus, Bangs, 1918
- Agapornis canus canus, (Gmelin, 1788)
- Black-winged Lovebird, Agapornis taranta, (Stanley, 1814) — or Abyssinian Lovebird
- Red-headed Lovebird, Agapornis pullarius, (Linnaeus, 1758)— or Red-faced Lovebird
- Agapornis pullarius pullarius, (Linnaeus, 1758)
- Agapornis pullarius ugandae, Neumann, 1908
- Black-collared Lovebird, Agapornis swindernianus, (Kuhl, 1820)— or Swindern’s Lovebird
- Agapornis swindernianus emini, Neumann, 1908
- Agapornis swindernianus swindernianus, (Kuhl, 1820)
- Agapornis swindernianus zenkeri, Reichenow, 1895
[edit] Species
| Species (wild-types) | |||
|---|---|---|---|
| Common and binomial names | Photograph | Description[2] | Range |
| Yellow-collared Lovebird or Masked Lovebird (Agapornis personatus) |
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14 cm (5.5 in) Large. Yellow and green. Has Blue tail feathers. | Northeast Tanzania |
| Fischer’s Lovebird (Agapornis fischeri) |
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14 cm (5.5 in) long. Mostly green, orange upper body and head, blue lower back and rump, red beak, white eyerings | South and southeast of Lake Victoria in northern Tanzania |
| Lilian’s Lovebird or Nyasa Lovebird (Agapornis lilianae) |
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13 cm (5 in) long. Mostly green including green back and green rump, orange head, red beak, white eyerings | Malawi |
| Black-cheeked Lovebird (Agapornis nigrigenis) |
 |
14 cm (5.5 in) long. Mostly green, brownish-black cheeks and throat, reddish-brown forehead and forecrown, orange upper chest, red beak, white eyerings | Zambia |
| Rosy-faced Lovebird or Peach-faced Lovebird (Agapornis roseicollis) |
 |
15 cm (6 in) long. Mostly green, orange face, blue lower back and rump, horn-coloured beak | Namibia, South Africa, Angola |
| Black-winged Lovebird or Abyssinian Lovebird (Agapornis taranta) |
 |
16.5 cm (6.5 in) long. Mostly green, red beak, some black wing feathers. Sexual dimorphism: only the male has red on forehead and crown, females plumage is all green | southern Eritrea to southwestern Ethiopia |
| Red-headed Lovebird or Red-faced Lovebird (Agapornis pullarius) |
 |
15 cm (6 in) long. Mostly green with red on upper neck and face. Sexual dimorphism: the male has more extensive and a darker red on face and head, and the male has a darker red beak than the female | Large part of central Africa |
| Grey-headed Lovebird or Madagascar Lovebird (Agapornis canus) |
 |
13 cm (5 in) long. Mostly green with darker green on back, pale grey beak. Sexual dimorphism: male has a grey upper body, neck and head. | Madagascar |
| Black-collared Lovebird or Swindern’s Lovebird (Agapornis swindernianus) |
 |
13.5 cm (5 in) long. Mostly green, brown collar which has a black upper margin at the back of the neck, dark grey/black beak | Equatorial Africa |
[edit] Nesting
Depending on the species of lovebird, the female will carry nesting material into the nest in various ways. The Peach-faced Lovebird tucks nesting material in the feathers of its rump,[5] while the Masked Lovebird carries nesting material back in its beak. Once the lovebirds start constructing their nest, mating will follow. During this time, the lovebirds will mate repeatedly. Eggs follow 3–5 days later. The female will spend hours inside her nesting box before eggs are laid. Once the first egg is laid, a new egg will follow every other day until the clutch is complete, typically at four to six eggs. Even without a nest, lovebirds sometimes produce eggs.
[edit] Feral populations
Hybrids (Fischer’s Lovebird x Masked Lovebird) in Nairobi, Kenya.
Feral populations of Fischer’s Lovebirds and Masked Lovebirds live in cities of East Africa. Also present there are interspecific hybrids between these two species. The hybrid has reddish-brown on head and has orange on upper chest, but otherwise resemble the Masked Lovebird.[6]
Feral lovebirds are also present in Phoenix, Arizona, USA.
[edit] Aviculture
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Recording of the blue masked lovebird variety.
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With their inclination to bond, they can form long-term relationships with people in tandem with their intra-species companions. Aggression is easily aroused in lovebirds, however, and biting may occur unless a bond is established with gentle handling. Provided with adequate space, a stimulating environment, and appropriate nutrition, a lovebird can become a cherished companion parrot. They love to snuggle and often preen their favorite people.
It is preferable to obtain birds bred in captivity, rather than birds caught from the wild. Wild birds may be harboring a disease, such as avian polyomavirus.[7] Captured wild lovebirds also may mourn the loss of association with a mate or a flock. Their age is likely to be unknown, and they may have an unsuitable personality for domestication. Lovebirds are not necessarily best kept in pairs, as their name suggests, although relationships with humans are then less likely to be as intense when paired. Birds kept individually or brought up hand-fed, make very good pets. However, single birds require frequent attention to stay happy, and if the owner has limited time to spend daily with a single lovebird, it is preferable to grant the lovebird a companion of the same species, or a companion of another parrot species known to get along well with lovebirds. Lovebirds can become very interactive with humans, and when comfortable, will willingly perch on a finger or shoulders.
Some Lovebirds talk, but many will not: there is a chance they may learn to mimic human sounds if taught to do so at a young age. Lovebirds are noisy, with calls ranging from cheerily pleasant to highly irritating; in the wild, parrots must call to each other over long distances to keep flocks together, and it is through such signals that most of their communication is made. It is best to spend frequent, short periods of time with a lovebird, rather than having just one or two interactions every day.[8]
[edit] Gender
Determining Lovebird sex is difficult. At maturity of one year, it may show signs of whether it is male or female, such as ripping up paper and stuffing it into its feathers (female behavior) or regurgitating for its owners (male behavior: the male feeds the nesting female). This behavior is not a reliable indicator. The only sure method is DNA testing. Companies that provide such service exist.[9]
[edit] Housing and environment
A Yellow-collared Lovebird perching by the entrance to a nest box in a large aviary at Honolulu Zoo, Hawaii, USA
Lovebirds require an appropriately sized cage or aviary. Recommended space per bird is min 1m×1m×1m. Lovebird’s beaks are made of keratin, which grows continuously. Chewing and destroying wood toys and perches helps to keep beaks trim. Cuttlebones help provide beak-trimming and a source of calcium and other necessary minerals. Natural perches and special rough surfaced perches of varying diameters placed at different levels in the cage will allow greater climbing mobility and gives them a choice to select the most comfortable spot to roost.[10] They also require plenty of toys, such as willow branches, swings, tunnels, boxes and safe things to chew on and play with.
Lack of toys, keeping the birdcage covered too many hours, and lack of companionship or social stimulation may lead to boredom, stress and psychological or behavioral problems (nervousness, aggression, feather-plucking, screaming, depression, immuno-suppression). Lovebirds are extremely social birds and will enjoy several hours of interaction a day. Without this interaction, daily exercise, a roomy cage/aviary, and many toys to play with, they may resort to feather-plucking, or screaming, and both behaviors can be difficult to cure. It is suggested that if the owner leaves the house that they leave a radio or TV set playing, to provide sound.[11] Lovebirds are intelligent, and if a relationship is to form they need a human who will dedicate lots of time with them. Lovebirds enjoy baths and like to sun themselves daily.
[edit] Grooming
As with pet parrots in general, the tips of lovebirds’ toenails should wear down adequately by the parrot climbing over rough surfaced perches. If the parrot has an inactive lifestyle, however, occasionally the toe nails grow long and may need to be trimmed.[12] Only the very tips of the toe nails are trimmed. If too much of a toe nail is trimmed away, it will be painful and bleed from the blood vessels in the centre of the nail.[12][13] Sharp pointed toe nails that scratch the owner can be blunted by simply filing the point.[13] These procedures are usually done with the help of an assistant carefully holding the parrot wrapped in a towel.[12][13]
[edit] Diet
- Whole Cereals & whole Grains : amaranth, barley, couscous, flax, whole-grain Pastas, oats, quinoa, whole wheat, wild rice, whole rices.
- Edible Blossoms & Flowers: Carnations, Chamomille, Chives, Dandelion, Day Lilies, Eucalyptus, Fruit tree’s blossoms, Herbs’ blossoms, Hibiscus, Honeysuckle, Impatiens, Lilac, Nasturiums, Pansies, Passion Flower (Passiflora), Roses, Sunflowers, Tulips, Violets. Note that the leaves of some of these plants are poisonous to Lovebirds.
- Greens &/or Weeds:
- mainly ; Bok-Choy, broccoli and/or cauliflower leaves, cabbage leaves, Collard greens, dandelion leaves, kelp, mustard leaves, seaweeds, Spirulina, Water cress…
- occasionally & sporadically ; Amaranth leaves, Beet leaves, Carambola (Starfruit), Chards, Parsley, Spinach & Turnip leaves. All of these feature high Oxalic-Acid content that induces production of Calcium Oxalates (crystals/stones) by binding Calcium & other trace Minerals present in foods & goods with which they’re ingested. This may lead to Calcium deficiencies (Hypocalcemia) in minor cases or in more severe cases to Liver &/or other internal organ damage or failure.
- Fruit (except avocados which are toxic): all Apple varieties (remove all seeds) , fresh Banana, all Berries varieties, all Citrus varieties, Grapes, Kiwi, Mango, Melons, Nectarine, Papaya, Peach, all Pear varieties, Plum, Star-fruit. Pits and seeds from every Citrus and Drupe species must always be discarded as they are intoxicating. However, achenes and tiny seeds from pseudo and true Berries (Bananas, Blueberries, Elderberries, Eggplants, Persimmons, Pomegranates, Raspberries, Strawberries, Tomatoes) are all suitable.[14]
- Legumes: Almonds, beans, lentils, peas, nuts and tofu.
- Grain and/or Legume sprouts: Adzuki beans, Alfalfa beans, Buckwheat, Lentils, Mungo beans, Pinto beans, Red Kidney beans, Sesame seeds, Sunflower seeds. Caution with only Lima and Navy beans’ sprouts which are toxic.
- Vegetables (except Uncooked Potatoes, Uncooked Onions and all Mushrooms): Beet, Broccoli, Cauliflower, Carrots, Cucumber, all Cabbage varieties, fresh beans, fresh Romane Lettuce, fresh Peas, Parsnip, all Pepper varieties, all Squash varieties, Sweet potatoes, Tomato, Turnip, Yams, Zucchini.
- Pellets specifically formulated for Lovebirds and/or for small parrots are all healthy additions.
- Other fat-free, healthy and nutritious human foods in very limited amounts.
Adding these foods provides additional nutrients and can prevent obesity and lipomas, as can substituting millet, which is relatively low in fat, for higher-fat seed mixes. Adult Lovebirds often do not always adapt readily to dietary additions, so care must be taken to introduce healthy diets as young as possible (ideally weaned onto fresh foods before introducing chicks onto seeds). Lovebirds like any other Parrots learn mainly by mimicry and thus most adult Lovebirds will be easily encouraged to try new foods by observing another bird eating the food, or by placing the new food on a mirror.
Parrot species (including cockatiels) are biologically vegetarian species.[citation needed] Consequently, they should be fed vegetarian diets that are ideally supplemented with vegetable proteins provided by the combination of any type of wholegrain/cereal with any type of legume/pulse. Eggs (hard-boiled and/or scrambled) are the only one appropriately healthy source of animal proteins.[citation needed] Mostly for birds in either breeding, growing, moulting and/or recovering conditions. High levels of proteins (most particularly animal proteins) is unhealthy for Lovebirds living under any alternate conditions (i.e. non-breeding, pets).[citation needed]
Intermediate species[further explanation needed] such as African Grey Parrots, Lovebirds, Poicephalus and Ringnecked Parakeets should be offered diets where pellets represent a moderate portion of about 1/3 to 1/2 of their daily diets.
Green and Blue series Peach-faced Lovebirds:
two parents with their two recently fledged chicks
[edit] Aggression problems with other birds and animal species
Because of their dominant and territorial nature, Lovebirds should be supervised when socializing with other species/genera (whether it be cat, dog, small mammal or other bird species). Lovebirds can be aggressive to other birds, even to other lovebirds. Hand raised Lovebirds tend not to be scared and pose even more of a threat to themselves. Toe biting can occur when Lovebirds are socializing/housed with small birds (i.e. Parrotlets, Budgies, and even docile Cockatiels). They should not be housed with other bird genera as they can be injured or pose a threat to other birds.
[edit] Pets and bird safety
Lovebirds are very vocal birds, making loud, high-pitched noises. Some make noise all day, especially during dawn and dusk. This is a normal parrot behavior as flock animals, where they are calling to each other before the start of the day and just before they settle down for the night.
Lovebirds are also very active and love to chew things. When they are flying within a household, it is wise to watch them carefully and protect any furniture, electrical wiring or anything else that they could possibly chew on. Try to place fresh willow or oak branches in a favorite spot (e.g. near a high/sunny platform) to satisfy this natural behavior. Other things to be aware of when keeping lovebirds (also applies to other pet birds) at home are the danger spots in the house, such as open toilet bowls for drowning, clear glass walls which might be rammed in full force by the bird, fumes from all teflon or anti-stick coating in the kitchen, microwave oven coatings and chemical fumes from regular household cleaning products. Interaction with other pets in the house must also be supervised, such as cats and dogs which may view the lovebird as a prey animal.
Some people who keep birds as pets practice the clipping of the flight feathers for safety reasons as mentioned above. This also promotes tameness between the bird and the owner as the bird will be less flighty.
Lovebirds of different species can mate and produce sterile hybrid offspring. These offspring display habits of both parents. It is recommended to only place birds of the same species together, or of the same sex for this reason.
[edit] In popular culture
Songs about lovebirds include:
- “Reincarnation of a Lovebird No 2” by Charles Mingus from the album Reincarnation of a Lovebird
In television and film:
- The animated television series 3rd & Bird features several characters described as lovebirds.
- Lovebirds play a symbolic role and figure prominently in Alfred Hitchcock‘s 1963 horror film, The Birds.
Clock
A clock is an instrument used to indicate, keep, and co-ordinate time. The word clock is derived ultimately (via Dutch, Northern French, and Medieval Latin) from the Celtic words clagan and clocca meaning “bell“. A silent instrument missing such a mechanism has traditionally been known as a timepiece.[1] In general usage today a “clock” refers to any device for measuring and displaying the time. Watches and other timepieces that can be carried on one’s person are often distinguished from clocks.[2]
The clock is one of the oldest human inventions, meeting the need to consistently measure intervals of time shorter than the natural units: the day; the lunar month; and the year. Devices operating on several different physical processes have been used over the millennia, culminating in the clocks of today.
Sundials and other devices
The sundial, which measures the time of day by using the sun casting a shadow onto a cylindrical stone, was widely used in ancient times. A well-constructed sundial can measure local solar time with reasonable accuracy, and sundials continued to be used to monitor the performance of clocks until the modern era. However, its practical limitations—it requires the sun to shine and does not work at all during the night—encouraged the use of other techniques for measuring time.
Candle clocks and sticks of incense that burn down at approximately predictable speeds have also been used to estimate the passing of time. In an hourglass, fine sand pours through a tiny hole at a constant rate and indicates a predetermined passage of an arbitrary period of time.
[edit] Water clocks
A scale model of Su Song‘s Astronomical Clock Tower, built in 11th century Kaifeng, China. It was driven by a large waterwheel, chain drive, and escapement mechanism.
Water clocks, also known as clepsydrae (sg: clepsydra), along with the sundials, are possibly the oldest time-measuring instruments, with the only exceptions being the vertical gnomon and the day-counting tally stick.[3] Given their great antiquity, where and when they first existed is not known and perhaps unknowable. The bowl-shaped outflow is the simplest form of a water clock and is known to have existed in Babylon and in Egypt around the 16th century BC. Other regions of the world, including India and China, also have early evidence of water clocks, but the earliest dates are less certain. Some authors, however, write about water clocks appearing as early as 4000 BC in these regions of the world.[4]
Greek astronomer, Andronicus of Cyrrhus, supervised the construction of the Tower of the Winds in Athens in the 1st century B.C.[5]
The Greek and Roman civilizations are credited for initially advancing water clock design to include complex gearing,[6][dead link] which was connected to fanciful automata and also resulted in improved accuracy. These advances were passed on through Byzantium and Islamic times, eventually making their way back to Europe. Independently, the Chinese developed their own advanced water clocks（水鐘）in 725 A.D., passing their ideas on to Korea and Japan.
Automatic clock of al-Jazari, 14th century.
Some water clock designs were developed independently and some knowledge was transferred through the spread of trade. Pre-modern societies do not have the same precise timekeeping requirements that exist in modern industrial societies, where every hour of work or rest is monitored, and work may start or finish at any time regardless of external conditions. Instead, water clocks in ancient societies were used mainly for astrological reasons. These early water clocks were calibrated with a sundial. While never reaching the level of accuracy of a modern timepiece, the water clock was the most accurate and commonly used timekeeping device for millennia, until it was replaced by the more accurate pendulum clock in 17th century Europe.
Islamic civilization is credited with further advancing the accuracy of clocks with elaborate engineering. In 797 (or possibly 801), the Abbasid caliph of Baghdad, Harun al-Rashid, presented Charlemagne with an Asian Elephant named Abul-Abbas together with a “particularly elaborate example” of a water[7] clock.
An elephant clock in a manuscript by Al-Jazari (1206 AD) from The Book of Knowledge of Ingenious Mechanical Devices.[8]
In the 13th century, Al-Jazari, an engineer who worked for Artuqid king of Diyar-Bakr, Nasir al-Din, made numerous clocks of all shapes and sizes. The book described 50 mechanical devices in 6 categories, including water clocks. The most reputed clocks included the Elephant, Scribe and Castle clocks, all of which have been successfully reconstructed. As well as telling the time, these grand clocks were symbols of status, grandeur and wealth of the Urtuq State.[citation needed]
[edit] Early mechanical clocks
None of the first clocks survived from 13th century Europe, but various mentions in church records reveal some of the early history of the clock.
The word horologia (from the Greek ὡρα, hour, and λέγειν, to tell) was used to describe all these devices,[9] but the use of this word (still used in several Romance languages) for all timekeepers conceals from us the true nature of the mechanisms. For example, there is a record that in 1176 Sens Cathedral installed a ‘horologe’[citation needed] but the mechanism used is unknown. According to Jocelin of Brakelond, in 1198 during a fire at the abbey of St Edmundsbury (now Bury St Edmunds), the monks ‘ran to the clock’ to fetch water, indicating that their water clock had a reservoir large enough to help extinguish the occasional fire.[10]
[edit] A new mechanism
The word clock (from the Latin word clocca, “bell”), which gradually supersedes “horologe”, suggests that it was the sound of bells which also characterized the prototype mechanical clocks that appeared during the 13th century in Europe.
Outside of Europe, the escapement mechanism had been known and used in medieval China, as the Song Dynasty horologist and engineer Su Song (1020–1101) incorporated it into his astronomical clock-tower of Kaifeng in 1088.[11][page needed] However, his astronomical clock and rotating armillary sphere still relied on the use of flowing water (i.e. hydraulics), while European clockworks of the following centuries shed this old method for a more efficient driving power of weights, in addition to the escapement mechanism.
A mercury clock, described in the Libros del saber, a Spanish work from AD 1277 consisting of translations and paraphrases of Arabic works, is sometimes quoted as evidence for Muslim knowledge of a mechanical clock. The first mercury powered automata clock was invented by Ibn Khalaf al-Muradi[12][13]
Between 1280 and 1320, there is an increase in the number of references to clocks and horologes in church records, and this probably indicates that a new type of clock mechanism had been devised. Existing clock mechanisms that used water power were being adapted to take their driving power from falling weights. This power was controlled by some form of oscillating mechanism, probably derived from existing bell-ringing or alarm devices. This controlled release of power – the escapement – marks the beginning of the true mechanical clock.
These mechanical clocks were intended for two main purposes: for signalling and notification (e.g. the timing of services and public events), and for modeling the solar system. The former purpose is administrative, the latter arises naturally given the scholarly interest in astronomy, science, astrology, and how these subjects integrated with the religious philosophy of the time. The astrolabe was used both by astronomers and astrologers, and it was natural to apply a clockwork drive to the rotating plate to produce a working model of the solar system.
Simple clocks intended mainly for notification were installed in towers, and did not always require faces or hands. They would have announced the canonical hours or intervals between set times of prayer. Canonical hours varied in length as the times of sunrise and sunset shifted. The more sophisticated astronomical clocks would have had moving dials or hands, and would have shown the time in various time systems, including Italian hours, canonical hours, and time as measured by astronomers at the time. Both styles of clock started acquiring extravagant features such as automata.
In 1283, a large clock was installed at Dunstable Priory; its location above the rood screen suggests that it was not a water clock[citation needed]. In 1292, Canterbury Cathedral installed a ‘great horloge’. Over the next 30 years there are brief mentions of clocks at a number of ecclesiastical institutions in England, Italy, and France. In 1322, a new clock was installed in Norwich, an expensive replacement for an earlier clock installed in 1273. This had a large (2 metre) astronomical dial with automata and bells. The costs of the installation included the full-time employment of two clockkeepers for two years[citation needed].
[edit] Early astronomical clocks
Richard of Wallingford pointing to a clock, his gift to St Albans Abbey
Besides the Chinese astronomical clock of Su Song in 1088 mentioned above, in Europe there were the clocks constructed by Richard of Wallingford in St Albans by 1336, and by Giovanni de Dondi in Padua from 1348 to 1364. They no longer exist, but detailed descriptions of their design and construction survive, [14] [15] and modern reproductions have been made[15]. They illustrate how quickly the theory of the mechanical clock had been translated into practical constructions, and also that one of the many impulses to their development had been the desire of astronomers to investigate celestial phenomena.
Wallingford’s clock had a large astrolabe-type dial, showing the sun, the moon’s age, phase, and node, a star map, and possibly the planets. In addition, it had a wheel of fortune and an indicator of the state of the tide at London Bridge. Bells rang every hour, the number of strokes indicating the time.[14]
Dondi’s clock was a seven-sided construction, 1 metre high, with dials showing the time of day, including minutes, the motions of all the known planets, an automatic calendar of fixed and movable feasts, and an eclipse prediction hand rotating once every 18 years.[15]
It is not known how accurate or reliable these clocks would have been. They were probably adjusted manually every day to compensate for errors caused by wear and imprecise manufacture.
Water clocks are sometimes still used today, and can be examined in places such as ancient castles and museums.
The Salisbury Cathedral clock, built in 1386, is considered to be the world’s oldest surviving mechanical clock that strikes the hours.[16]
[edit] Later developments
One of the first pocket watches, called “Nuremberg Egg”, made around 1510 and attributed to Peter Henlein, (Germanisches Nationalmuseum, Nuremberg)
Clockmakers developed their art in various ways. Building smaller clocks was a technical challenge, as was improving accuracy and reliability. Clocks could be impressive showpieces to demonstrate skilled craftsmanship, or less expensive, mass-produced items for domestic use. The escapement in particular was an important factor affecting the clock’s accuracy, so many different mechanisms were tried.
Spring-driven clocks appeared during the 15th century,[17][18][19] although they are often erroneously credited to Nuremberg watchmaker Peter Henlein (or Henle, or Hele) around 1511.[20][21][22] The earliest existing spring driven clock is the chamber clock given to Peter the Good, Duke of Burgundy, around 1430, now in the Germanisches Nationalmuseum.[18] Spring power presented clockmakers with a new problem: how to keep the clock movement running at a constant rate as the spring ran down. This resulted in the invention of the stackfreed and the fusee in the 15th century, and many other innovations, down to the invention of the modern going barrel in 1760.
Early clock dials did not use minutes and seconds. A clock with a dial indicating minutes was illustrated in a 1475 manuscript by Paulus Almanus,[23] and some 15th-century clocks in Germany indicated minutes and seconds.[24] An early record of a second hand on a clock dates back to about 1560 on a clock now in the Fremersdorf collection.[citation needed] However, this clock could not have been accurate, and the second hand was probably for indicating that the clock was working.
During the 15th and 16th centuries, clockmaking flourished, particularly in the metalworking towns of Nuremberg and Augsburg, and in Blois, France. Some of the more basic table clocks have only one time-keeping hand, with the dial between the hour markers being divided into four equal parts making the clocks readable to the nearer 15 minutes. Other clocks were exhibitions of craftsmanship and skill, incorporating astronomical indicators and musical movements. The cross-beat escapement was invented in 1584 by Jost Bürgi, who also developed the remontoire. Bürgi’s clocks were a great improvement in accuracy as they were correct to within a minute a day.[25][26] These clocks helped the 16th-century astronomer Tycho Brahe to observe astronomical events with much greater precision than before.
A mechanical weight-driven astronomical clock with a verge-and-foliot escapement, a striking train of gears, an alarm, and a representation of the moon’s phases was described by the Ottoman engineer Taqi al-Din in his book, The Brightest Stars for the Construction of Mechanical Clocks (Al-Kawākib al-durriyya fī wadh’ al-bankāmat al-dawriyya), published in 1556-1559.[27] Similarly to earlier 15th-century European alarm clocks,[28][29] it was capable of sounding at a specified time, achieved by placing a peg on the dial wheel. At the requested time, the peg activated a ringing device. The clock had three dials which indicated hours, degrees and minutes. He later made an observational clock for the Istanbul observatory of Taqi al-Din (1577–1580), describing it as “a mechanical clock with three dials which show the hours, the minutes, and the seconds.” This was an important innovation in 16th-century practical astronomy, as at the start of the century clocks were not accurate enough to be used for astronomical purposes.[30]
French rococo bracket clocks, (Museum of Time, Besançon)
The next development in accuracy occurred after 1656 with the invention of the pendulum clock. Galileo had the idea to use a swinging bob to regulate the motion of a time-telling device earlier in the 17th century. Christiaan Huygens, however, is usually credited as the inventor. He determined the mathematical formula that related pendulum length to time (99.38 cm or 39.13 inches for the one second movement) and had the first pendulum-driven clock made. In 1670, the English clockmaker William Clement created the anchor escapement,[citation needed] an improvement over Huygens’ crown escapement[citation needed]. Within just one generation, minute hands and then second hands were added.
A major stimulus to improving the accuracy and reliability of clocks was the importance of precise time-keeping for navigation. The position of a ship at sea could be determined with reasonable accuracy if a navigator could refer to a clock that lost or gained less than about 10 seconds per day. This clock could not contain a pendulum, which would be virtually useless on a rocking ship. Many European governments offered a large prize for anyone who could determine longitude accurately; for example, Great Britain offered 20,000 pounds, equivalent to millions of dollars today. The reward was eventually claimed in 1761 by John Harrison, who dedicated his life to improving the accuracy of his clocks. His H5 clock was in error by less than 5 seconds over 10 weeks.[31]
The excitement over the pendulum clock had attracted the attention of designers, resulting in a proliferation of clock forms. Notably, the longcase clock (also known as the grandfather clock) was created to house the pendulum and works. The English clockmaker William Clement is also credited with developing this form in 1670 or 1671. It was also at this time that clock cases began to be made of wood and clock faces to utilize enamel as well as hand-painted ceramics.
French decimal clock from the time of the French Revolution
On November 17, 1797, Eli Terry received his first patent for a clock. Terry is known as the founder of the American clock-making industry.
Alexander Bain, Scottish clockmaker, patented the electric clock in 1840. The electric clock’s mainspring is wound either with an electric motor or with an electro-magnet and armature. In 1841, he first patented the electromagnetic pendulum.
The development of electronics in the 20th century led to clocks with no clockwork parts at all. Time in these cases is measured in several ways, such as by the vibration of a tuning fork, the behaviour of quartz crystals, or the quantum vibrations of atoms. Even mechanical clocks have since come to be largely powered by batteries, removing the need for winding.
[edit] How clocks work
The invention of the mechanical clock in the 13th century initiated a change in timekeeping methods from continuous processes, such as the motion of the gnomon‘s shadow on a sundial or the flow of liquid in a water clock, to repetitive oscillatory processes, like the swing of a pendulum or the vibration of a quartz crystal, which were more accurate.[32] All modern clocks use oscillation.
Although the methods they use vary, all oscillating clocks, mechanical and digital and atomic, work similarly and can be divided into analogous parts.[33][34][35] They consist of an object that repeats the same motion over and over again, an oscillator, with a precisely constant time interval between each repetition, or ‘beat’. Attached to the oscillator is a controller device, which sustains the oscillator’s motion by replacing the energy it loses to friction, and converts its oscillations into a series of pulses. The pulses are then added up in a chain of some type of counters to express the time in convenient units, usually seconds, minutes, hours, etc. Then finally some kind of indicator displays the result in a human-readable form.
[edit] Power source
This provides power to keep the clock going.
- In mechanical clocks, this is either a weight suspended from a cord wrapped around a pulley, or a spiral spring called a mainspring.
- In electric clocks, it is either a battery or the AC power line.
Since clocks must run continuously, there is often a small secondary power source to keep the clock going temporarily during interruptions in the main power. In old mechanical clocks, a maintaining power spring kept the clock turning while the mainspring was being wound. In quartz clocks that use AC power, a small backup battery is often included to keep the clock running if it is unplugged temporarily from the wall.
[edit] Oscillator
The timekeeping element in every modern clock is a harmonic oscillator, a physical object (resonator) that vibrates or oscillates repetitively at a precisely constant frequency.[36]
- In mechanical clocks, this is either a pendulum or a balance wheel.
- In some early electronic clocks and watches such as the Accutron, it is a tuning fork.
- In quartz clocks and watches, it is a quartz crystal.
- In atomic clocks, it is the vibration of electrons in atoms as they emit microwaves.
- In early mechanical clocks before 1657, it was a crude balance wheel or foliot which was not a harmonic oscillator because it lacked a balance spring. As a result they were very inaccurate, with errors of perhaps an hour a day.[37]
The advantage of a harmonic oscillator over other forms of oscillator is that it employs resonance to vibrate at a precise natural resonant frequency or ‘beat’ dependent only on its physical characteristics, and resists vibrating at other rates. The possible precision achievable by a harmonic oscillator is measured by a parameter called its Q,[38][39] or quality factor, which increases (other things being equal) with its resonant frequency.[40] This is why there has been a long term trend toward higher frequency oscillators in clocks. Balance wheels and pendulums always include a means of adjusting the rate of the timepiece. Quartz timepieces sometimes include a rate screw that adjusts a capacitor for that purpose. Atomic clocks are primary standards, and their rate cannot be adjusted.
[edit] Synchronized or slave clocks
Some clocks rely for their accuracy on an external oscillator; that is, they are automatically synchronized to a more accurate clock:
- Slave clocks, used in large institutions and schools from the 1860s to the 1970s, kept time with a pendulum, but were wired to a master clock in the building, and periodically received a signal to synchronize them with the master, often on the hour.[41] Later versions without pendulums were triggered by a pulse from the master clock and certain sequences used to force rapid synchronization following a power failure.
- Synchronous electric clocks don’t have an internal oscillator, but rely on the 50 or 60 Hz oscillation of the AC power line, which is synchronized by the utility to a precision oscillator. This drives a synchronous motor in the clock which rotates once for every cycle of the line voltage, and drives the gear train.
- Computer real time clocks keep time with a quartz crystal, but are periodically (usually weekly) synchronized over the internet to atomic clocks (UTC), using a system called Network Time Protocol.
- Radio clocks keep time with a quartz crystal, but are periodically (often daily) synchronized to atomic clocks (UTC) with time signals from government radio stations like WWV, WWVB, CHU, DCF77 and the GPS system.
[edit] Controller
This has the dual function of keeping the oscillator running by giving it ‘pushes’ to replace the energy lost to friction, and converting its vibrations into a series of pulses that serve to measure the time.
- In mechanical clocks, this is the escapement, which gives precise pushes to the swinging pendulum or balance wheel, and releases one gear tooth of the escape wheel at each swing, allowing all the clock’s wheels to move forward a fixed amount with each swing.
- In electronic clocks this is an electronic oscillator circuit that gives the vibrating quartz crystal or tuning fork tiny ‘pushes’, and generates a series of electrical pulses, one for each vibration of the crystal, which is called the clock signal.
- In atomic clocks the controller is an evacuated microwave cavity attached to a microwave oscillator controlled by a microprocessor. A thin gas of cesium atoms is released into the cavity where they are exposed to microwaves. A laser measures how many atoms have absorbed the microwaves, and an electronic feedback control system called a phase locked loop tunes the microwave oscillator until it is at the exact frequency that causes the atoms to vibrate and absorb the microwaves. Then the microwave signal is divided by digital counters to become the clock signal.[42]
In mechanical clocks, the low Q of the balance wheel or pendulum oscillator made them very sensitive to the disturbing effect of the impulses of the escapement, so the escapement had a great effect on the accuracy of the clock, and many escapement designs were tried. The higher Q of resonators in electronic clocks makes them relatively insensitive to the disturbing effects of the drive power, so the driving oscillator circuit is a much less critical component.[36]
[edit] Counter chain
This counts the pulses and adds them up to get traditional time units of seconds, minutes, hours, etc. It usually has a provision for setting the clock by manually entering the correct time into the counter.
- In mechanical clocks this is done mechanically by a gear train, known as the wheel train. The gear train also has a second function; to transmit mechanical power from the power source to run the oscillator. There is a friction coupling called the ‘cannon pinion’ between the gears driving the hands and the rest of the clock, allowing the hands to be turned by a knob on the back to set the time.[43]
- In digital clocks a series of integrated circuit counters or dividers add the pulses up digitally, using binary logic. Often pushbuttons on the case allow the hour and minute counters to be incremented and decremented to set the time.
[edit] Indicator
This displays the count of seconds, minutes, hours, etc. in a human readable form.
- The earliest mechanical clocks in the 13th century didn’t have a visual indicator and signalled the time audibly by striking bells. Many clocks to this day are striking clocks which strike the hour.
- Analog clocks, including almost all mechanical and some electronic clocks, have a traditional dial or clock face, that displays the time in analog form with a moving hour and minute hand. In quartz clocks with analog faces, a 1 Hz signal from the counters actuates a stepper motor which moves the second hand forward at each pulse, and the minute and hour hands are moved by gears from the shaft of the second hand.
- Digital clocks display the time in periodically changing digits on a digital display.
- Talking clocks and the speaking clock services provided by telephone companies speak the time audibly, using either recorded or digitally synthesized voices.
[edit] Types
Clocks can be classified by the type of time display, as well as by the method of timekeeping.
[edit] Time display methods
[edit] Analog clocks
A linear clock at London‘s Piccadilly Circus tube station. The 24 hour band moves across the static map, keeping pace with the apparent movement of the sun above ground, and a pointer fixed on London points to the current time
Analog clocks usually indicate time using angles. The most common clock face uses a fixed numbered dial or dials and moving hand or hands. It usually has a circular scale of 12 hours, which can also serve as a scale of 60 minutes, and 60 seconds if the clock has a second hand. Many other styles and designs have been used throughout the years, including dials divided into 6, 8, 10, and 24 hours. The only other widely used clock face today is the 24 hour analog dial, because of the use of 24 hour time in military organizations and timetables. The 10-hour clock was briefly popular during the French Revolution, when the metric system was applied to time measurement, and an Italian 6 hour clock was developed in the 18th century, presumably to save power (a clock or watch striking 24 times uses more power).
Another type of analog clock is the sundial, which tracks the sun continuously, registering the time by the shadow position of its gnomon. Sundials use some or part of the 24 hour analog dial. There also exist clocks which use a digital display despite having an analog mechanism—these are commonly referred to as flip clocks.
Alternative systems have been proposed. For example, the Twelv clock indicates the current hour using one of twelve colors, and indicates the minute by showing a proportion of a circular disk, similar to a moon phase.
[edit] Digital clocks
Digital clock outside Kanazawa Station displaying the time by controlling valves on a fountain
Basic digital clock radio
Cell phone display including a clock
A typical Deutsche Bahn Train station clock
John Harrison‘s Chronometer H5
Digital clocks display a numeric representation of time. Two numeric display formats are commonly used on digital clocks:
- the 24-hour notation with hours ranging 00–23;
- the 12-hour notation with AM/PM indicator, with hours indicated as 12AM, followed by 1AM–11AM, followed by 12PM, followed by 1PM–11PM (a notation mostly used in the United States and Canada).
Most digital clocks use an LCD, LED, or VFD display; many other display technologies are used as well (cathode ray tubes, nixie tubes, etc.). After a reset, battery change or power failure, digital clocks without a backup battery or capacitor either start counting from 12:00, or stay at 12:00, often with blinking digits indicating that the time needs to be set. Some newer clocks will actually reset themselves based on radio or Internet time servers that are tuned to national atomic clocks. Since the advent of digital clocks in the 1960s, the use of analog clocks has declined significantly.
[edit] Auditory clocks
For convenience, distance, telephony or blindness, auditory clocks present the time as sounds. The sound is either spoken natural language, (e.g. “The time is twelve thirty-five”), or as auditory codes (e.g. number of sequential bell rings on the hour represents the number of the hour like the bell Big Ben). Most telecommunication companies also provide a speaking clock service as well.
[edit] Purposes
Clocks are in homes, offices and many other places; smaller ones (watches) are carried on the wrist; larger ones are in public places, e.g. a train station or church. A small clock is often shown in a corner of computer displays, mobile phones and many MP3 players.
The purpose of a clock is not always to display the time. It may also be used to control a device according to time, e.g. an alarm clock, a VCR, or a time bomb (see: counter). However, in this context, it is more appropriate to refer to it as a timer or trigger mechanism rather than strictly as a clock.
Computers depend on an accurate internal clock signal to allow synchronized processing. (A few research projects are developing CPUs based on asynchronous circuits.) Some computers also maintain time and date for all manner of operations whether these be for alarms, event initiation, or just to display the time of day. The internal computer clock is generally kept running by a small battery. Many computers will still function even if the internal clock battery is dead, but the computer clock will need to be reset each time the computer is restarted, since once power is lost, time is also lost.
[edit] Ideal clocks
An ideal clock is a scientific principle that measures the ratio of the duration of natural processes, and thus will give the time measure for use in physical theories.[citation needed] Therefore, to define an ideal clock in terms of any physical theory would be circular. An ideal clock is more appropriately defined in relationship to the set of all physical processes.
This leads to the following definitions:
- A clock is a recurrent process and a counter.
- A good clock is one which, when used to measure other recurrent processes, finds many of them to be periodic.
- An ideal clock is a clock (i.e., recurrent process) that makes the most other recurrent processes periodic.
The recurrent, periodic process (e.g. a metronome) is an oscillator and typically generates a clock signal. Sometimes that signal alone is (confusingly) called “the clock”, but sometimes “the clock” includes the counter, its indicator, and everything else supporting it.
This definition can be further improved by the consideration of successive levels of smaller and smaller error tolerances. While not all physical processes can be surveyed, the definition should be based on the set of physical processes which includes all individual physical processes which are proposed for consideration. Since atoms are so numerous and since, within current measurement tolerances they all beat in a manner such that if one is chosen as periodic then the others are all deemed to be periodic also, it follows that atomic clocks represent ideal clocks to within present measurement tolerances and in relation to all presently known physical processes. However, they are not so designated by fiat. Rather, they are designated as the current ideal clock because they are currently the best instantiation of the definition.
[edit] Navigation
Navigation by ships and planes depends on the ability to measure latitude and longitude. Latitude is fairly easy to determine through celestial navigation, but the measurement of longitude requires accurate measurement of time. This need was a major motivation for the development of accurate mechanical clocks. John Harrison created the first highly accurate marine chronometer in the mid-18th century. The Noon gun in Cape Town still fires an accurate signal to allow ships to check their chronometers.
Use of an atomic clock in radio signal producing satellites is fundamental to the operation of GPS (Global Positioning System) navigation devices.
[edit] Seismology
In determining the location of an earthquake, the arrival time of several types of seismic wave at a minimum of four dispersed observers is dependent upon each observer recording wave arrival times according to a common clock.
[edit] Specific types of clocks
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light.[1] Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. Information is carried by systematically changing (modulating) some property of the radiated waves, such as amplitude, frequency, phase, or pulse width. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be detected and transformed into sound or other signals that carry information.
Etymology
The etymology of “radio” or “radiotelegraphy” reveals that it was called “wireless telegraphy“, which was shortened to “wireless” in Britain. The prefix radio- in the sense of wireless transmission, was first recorded in the word radioconductor, a description provided by the French physicist Édouard Branly in 1897. It is based on the verb to radiate (in Latin “radius” means “spoke of a wheel, beam of light, ray”). This word also appears in a 1907 article by Lee De Forest, it was adopted by the United States Navy in 1912, and became common by the time of the first commercial broadcasts in the United States in the 1920s. (The noun “broadcasting” itself came from an agricultural term, meaning “scattering seeds widely”.) The term was then adopted by other languages in Europe and Asia. British Commonwealth countries continued to mainly use the term “wireless” until the mid-20th century, though the magazine of the BBC in the UK has been called Radio Times ever since it was first published in the early 1920s.
In recent years the term “wireless” has gained renewed popularity through the rapid growth of short-range computer networking, e.g., Wireless Local Area Network (WLAN), Wi-Fi, and Bluetooth, as well as mobile telephony, e.g., GSM and UMTS. Today, the term “radio” often refers to the actual transceiver device or chip, whereas “wireless” refers to the system and/or method used for radio communication; hence one talks about radio transceivers and Radio Frequency Identification (RFID), but about wireless devices and wireless sensor networks.
[edit] Processes
Radio systems used for communications will have the following elements. With more than 100 years of development, each process is implemented by a wide range of methods, specialized for different communications purposes.
Each system contains a transmitter. This consists of a source of electrical energy, producing alternating current of a desired frequency of oscillation. The transmitter contains a system to modulate (change) some property of the energy produced to impress a signal on it. This modulation might be as simple as turning the energy on and off, or altering more subtle properties such as amplitude, frequency, phase, or combinations of these properties. The transmitter sends the modulated electrical energy to a tuned resonant antenna; this structure converts the rapidly changing alternating current into an electromagnetic wave that can move through free space (sometimes with a particular polarization).
Electromagnetic waves travel through space either directly, or have their path altered by reflection, refraction or diffraction. The intensity of the waves diminishes due to geometric dispersion (the inverse-square law); some energy may also be absorbed by the intervening medium in some cases. Noise will generally alter the desired signal; this electromagnetic interference comes from natural sources, as well as from artificial sources such as other transmitters and accidental radiators. Noise is also produced at every step due to the inherent properties of the devices used. If the magnitude of the noise is large enough, the desired signal will no longer be discernible; this is the fundamental limit to the range of radio communications.
The electromagnetic wave is intercepted by a tuned receiving antenna; this structure captures some of the energy of the wave and returns it to the form of oscillating electrical currents. At the receiver, these currents are demodulated, which is conversion to a usable signal form by a detector sub-system. The receiver is “tuned” to respond preferentially to the desired signals, and reject undesired signals.
Early radio systems relied entirely on the energy collected by an antenna to produce signals for the operator. Radio became more useful after the invention of electronic devices such as the vacuum tube and later the transistor, which made it possible to amplify weak signals. Today radio systems are used for applications from walkie-talkie children’s toys to the control of space vehicles, as well as for broadcasting, and many other applications.
[edit] Electromagnetic spectrum
Radio frequencies occupy the range from a few tens of hertz to three hundred gigahertz, although commercially important uses of radio use only a small part of this spectrum.[2] Other types of electromagnetic radiation, with frequencies above the RF range, are microwave, infrared, visible light, ultraviolet, X-rays and gamma rays. Since the energy of an individual photon of radio frequency is too low to remove an electron from an atom, radio waves are classified as non-ionizing radiation.
[edit] History
[edit] 19th century
The meaning and usage of the word “radio” has developed in parallel with developments within the field of communications and can be seen to have three distinct phases: electromagnetic waves and experimentation; wireless communication and technical development; and radio broadcasting and commercialization. Many individuals—inventors, engineers, developers, businessmen – contributed to produce the modern idea of radio and thus the origins and ‘invention’ are multiple and controversial. Early radio designs could not transmit sound or speech and were called the “wireless telegraph“.
Development from a laboratory demonstration to a commercial entity spanned several decades and required the efforts of many practitioners. In 1878, David E. Hughes noticed that sparks could be heard in a telephone receiver when experimenting with his carbon microphone. He developed this carbon-based detector further and eventually could detect signals over a few hundred yards. He demonstrated his discovery to the Royal Society in 1880, but was told it was merely induction, and therefore abandoned further research.
Experiments, later patented, were undertaken by Thomas Edison and his employees of Menlo Park.[3] Edison applied in 1885 to the U.S. Patent Office for his patent on an electrostatic coupling system between elevated terminals. The patent was granted as U.S. Patent 465,971 on December 29, 1891. The Marconi Company would later purchase rights to the Edison patent to protect them legally from lawsuits.[4]
Tesla demonstrating wireless transmissions during his high frequency and potential lecture of 1891. After continued research, Tesla presented the fundamentals of radio in 1893.
In 1893, in St. Louis, Missouri, Nikola Tesla made devices for his experiments with electricity. Addressing the Franklin Institute in Philadelphia and the National Electric Light Association, he described and demonstrated the principles of his wireless work.[5] The descriptions contained all the elements that were later incorporated into radio systems before the development of the vacuum tube. He initially experimented with magnetic receivers, unlike the coherers (detecting devices consisting of tubes filled with iron filings which had been invented by Temistocle Calzecchi-Onesti at Fermo in Italy in 1884) used by Guglielmo Marconi and other early experimenters.[6]
A demonstration of wireless telegraphy took place in the lecture theater of the Oxford University Museum of Natural History on August 14, 1894, carried out by Professor Oliver Lodge and Alexander Muirhead. During the demonstration a radio signal was sent from the neighboring Clarendon laboratory building, and received by apparatus in the lecture theater.
In 1895 Alexander Stepanovich Popov built his first radio receiver, which contained a coherer. Further refined as a lightning detector, it was presented to the Russian Physical and Chemical Society on May 7, 1895. A depiction of Popov’s lightning detector was printed in the Journal of the Russian Physical and Chemical Society the same year. Popov’s receiver was created on the improved basis of Lodge’s receiver, and originally intended for reproduction of its experiments.
In 1895, Marconi built a wireless system capable of transmitting signals at long distances (1.5 mi./ 2.4 km).[7][8] In radio transmission technology, early public experimenters had made short distance broadcasts.[9] Marconi achieved long range signalling due to a wireless transmitting apparatus and a radio receiver claimed by him.[10][11] From Marconi’s experiments, the phenomenon that transmission range is proportional to the square of antenna height is known as “Marconi’s law“.[12] This formula represents a physical law that radio devices use. Marconi’s experimental apparatus proved to be a complete, commercially successful radio transmission system.[11][13][14] According to the Proceedings of the United States Naval Institute in 1899, the Marconi instruments had a “[…] coherer, principle of which was discovered some twenty years ago, [and was] the only electrical instrument or device contained in the apparatus that is at all new”.[15]
Telephone Herald in Budapest, Hungary (1901).
In 1896, Marconi was awarded British patent 12039, Improvements in transmitting electrical impulses and signals and in apparatus there-for, for radio. In 1897, he established a radio station on the Isle of Wight, England. Marconi opened his “wireless” factory in Hall Street, Chelmsford, England in 1898, employing around 50 people. Shortly after the 1900s, Marconi held the patent rights for radio.
[edit] 20th century
The next advancement was the vacuum tube detector, invented by Westinghouse engineers. On Christmas Eve, 1906, Reginald Fessenden used a synchronous rotary-spark transmitter for the first radio program broadcast, from Ocean Bluff-Brant Rock, Massachusetts. Ships at sea heard a broadcast that included Fessenden playing O Holy Night on the violin and reading a passage from the Bible. This was, for all intents and purposes, the first transmission of what is now known as amplitude modulation or AM radio. The first radio news program was broadcast August 31, 1920 by station 8MK in Detroit, Michigan, which survives today as all-news format station WWJ under ownership of the CBS network. The first college radio station began broadcasting on October 14, 1920, from Union College, Schenectady, New York under the personal call letters of Wendell King, an African-American student at the school.[16] That month 2ADD, later renamed WRUC in 1947, aired what is believed to be the first public entertainment broadcast in the United States, a series of Thursday night concerts initially heard within a 100-mile (160 km) radius and later for a 1,000-mile (1,600 km) radius. In November 1920, it aired the first broadcast of a sporting event.[16][17] At 9 pm on August 27, 1920, Sociedad Radio Argentina aired a live performance of Richard Wagner’s Parsifal opera from the Coliseo Theater in downtown Buenos Aires. Only about twenty homes in the city had receivers to tune in this radio program. Meanwhile, regular entertainment broadcasts commenced in 1922 from the Marconi Research Centre at Writtle, England.
Sports broadcasting began at this time as well, including the first broadcast college football game.[18]
Patent rights in the United States during the 1900s.
In 1943 the United States Supreme Court upheld Tesla’s patent for radio, number 645,576 (1897), with the supreme court’s justification that claim 16 in Marconi’s related patent, number 763,772 (1904), contained nothing new not having been published earlier and registered by Tesla, Lodge, and others. After years of patent battles by Marconi’s company, the United States Supreme Court, in the 1943 case “Marconi Wireless Telegraph co. of America v. United States”, held regarding the priority of engineering advances concerning the invention of radio that “[but] it is now held that in the important advance upon his basic patent Marconi did nothing that had not already been seen and disclosed”.[19][20] The decision effectively awarded priority of the invention of radio to Tesla and his 1893 presentation in St. Louis.[21] Although Marconi claimed that he had no knowledge of prior art taken from Tesla’s patents, the supreme court considered his claim false.[22] In addition to the June 21, 1943 ruling made by the supreme court, the United States Court of Claims also invalidated the fundamental Marconi patent earlier, in 1935.[23] This case defined radio by the statement: “A radio communication system requires two tuned circuits each at the transmitter and receiver, all four tuned to the same frequency.”[24] Because Tesla’s 1897 patent for radio was intended for general transmission of energy, the court determined that Tesla’s patent clearly was the first to disclose a system which could be used for wireless communication of intelligible messages (such as human voice and music) and used the four-circuit tuned combination.[25]
An American girl listens to a radio during the Great Depression.
In contrast, related developments in the United Kingdom saw the British High Court uphold Marconi’s British Patent 7,777 that was issued on April 26, 1900. This British patent held by Marconi disclosed a four-circuit system, which was strikingly similar to a four-circuit system disclosed in U.S. patent #645,576 that was issued earlier to Tesla on March 20, 1900. On the matter of invention, it is held that Marconi knowingly and unknowingly used the scientific and experimental work of many others who were devising their own radio tuning apparatus’ around the same time, such as the work of American electrical engineer John Stone Stone who was issued several U.S. patents between 1904 and 1908. However, what made Marconi more successful than any other was his ability to commercialize radio and its associated equipment into a global business.[26]
One of the first developments in the early 20th century was that aircraft used commercial AM radio stations for navigation. This continued until the early 1960s when VOR systems became widespread.[27] In the early 1930s, single sideband and frequency modulation were invented by amateur radio operators. By the end of the decade, they were established commercial modes. Radio was used to transmit pictures visible as television as early as the 1920s. Commercial television transmissions started in North America and Europe in the 1940s.
The Regency TR-1 which used Texas Instruments‘ NPN transistors was the world’s first commercially-produced transistor radio.
In 1954, the Regency company introduced a pocket transistor radio, the TR-1, powered by a “standard 22.5 V Battery”. In 1955, the newly formed Sony company introduced its first transistorized radio.[28] It was small enough to fit in a vest pocket, and able to be powered by a small battery. It was durable, because it had no vacuum tubes to burn out. Over the next 20 years, transistors replaced tubes almost completely except for very high-power transmitter uses. By 1963, color television was being regularly broadcast commercially (though not all broadcasts or programs were in color), and the first (radio) communication satellite, Telstar, was launched. In the late 1960s, the U.S. long-distance telephone network began to convert to a digital network, employing digital radios for many of its links. In the 1970s, LORAN became the premier radio navigation system. Soon, the U.S. Navy experimented with satellite navigation, culminating in the invention and launch of the GPS constellation in 1987. In the early 1990s, amateur radio experimenters began to use personal computers with audio cards to process radio signals. In 1994, the U.S. Army and DARPA launched an aggressive, successful project to construct a software-defined radio that can be programmed to be virtually any radio by changing its software program. Digital transmissions began to be applied to broadcasting in the late 1990s.
[edit] Uses of radio
Early uses were maritime, for sending telegraphic messages using Morse code between ships and land. The earliest users included the Japanese Navy scouting the Russian fleet during the Battle of Tsushima in 1905. One of the most memorable uses of marine telegraphy was during the sinking of the RMS Titanic in 1912, including communications between operators on the sinking ship and nearby vessels, and communications to shore stations listing the survivors.
Radio was used to pass on orders and communications between armies and navies on both sides in World War I; Germany used radio communications for diplomatic messages once it discovered that its submarine cables had been tapped by the British. The United States passed on President Woodrow Wilson‘s Fourteen Points to Germany via radio during the war. Broadcasting began from San Jose, California in 1909,[29] and became feasible in the 1920s, with the widespread introduction of radio receivers, particularly in Europe and the United States. Besides broadcasting, point-to-point broadcasting, including telephone messages and relays of radio programs, became widespread in the 1920s and 1930s. Another use of radio in the pre-war years was the development of detection and locating of aircraft and ships by the use of radar (RAdio Detection And Ranging).
Today, radio takes many forms, including wireless networks and mobile communications of all types, as well as radio broadcasting. Before the advent of television, commercial radio broadcasts included not only news and music, but dramas, comedies, variety shows, and many other forms of entertainment (the era from 1930 to the mid-1950s is commonly called radio’s “Golden Age”). Radio was unique among methods of dramatic presentation in that it used only sound. For more, see radio programming.
[edit] Audio
A Fisher 500 AM/FM hi-fi receiver from 1959.
AM radio uses amplitude modulation, in which the amplitude of the transmitted signal is made proportional to the sound amplitude captured (transduced) by the microphone, while the transmitted frequency remains unchanged. Transmissions are affected by static and interference because lightning and other sources of radio emissions on the same frequency add their amplitudes to the original transmitted amplitude. In the early part of the 20th century, American AM radio stations broadcast with powers as high as 500 kW, and some could be heard worldwide; these stations’ transmitters were commandeered for military use by the US Government during World War II. Currently, the maximum broadcast power for a civilian AM radio station in the United States and Canada is 50 kW, and the majority of stations that emit signals this powerful were grandfathered in (see List of 50kw AM radio stations in the USA). In 1986 KTNN received the last granted 50,000 watt license. These 50 kW stations are generally called “clear channel” stations (not to be confused with Clear Channel Communications), because within North America each of these stations has exclusive use of its broadcast frequency throughout part or all of the broadcast day.
Bush House, home of the BBC World Service.
FM broadcast radio sends music and voice with higher fidelity than AM radio. In frequency modulation, amplitude variation at the microphone causes the transmitter frequency to fluctuate. Because the audio signal modulates the frequency and not the amplitude, an FM signal is not subject to static and interference in the same way as AM signals. Due to its need for a wider bandwidth, FM is transmitted in the Very High Frequency (VHF, 30 MHz to 300 MHz) radio spectrum. VHF radio waves act more like light, traveling in straight lines; hence the reception range is generally limited to about 50–100 miles. During unusual upper atmospheric conditions, FM signals are occasionally reflected back towards the Earth by the ionosphere, resulting in long distance FM reception. FM receivers are subject to the capture effect, which causes the radio to only receive the strongest signal when multiple signals appear on the same frequency. FM receivers are relatively immune to lightning and spark interference.
High power is useful in penetrating buildings, diffracting around hills, and refracting in the dense atmosphere near the horizon for some distance beyond the horizon. Consequently, 100,000 watt FM stations can regularly be heard up to 100 miles (160 km) away, and farther (e.g., 150 miles, 240 km) if there are no competing signals. A few old, “grandfathered” stations do not conform to these power rules. WBCT-FM (93.7) in Grand Rapids, Michigan, USA, runs 320,000 watts ERP, and can increase to 500,000 watts ERP by the terms of its original license. Such a huge power level does not usually help to increase range as much as one might expect, because VHF frequencies travel in nearly straight lines over the horizon and off into space. Nevertheless, when there were fewer FM stations competing, this station could be heard near Bloomington, Illinois, USA, almost 300 miles (500 km) away.[citation needed]
FM subcarrier services are secondary signals transmitted in a “piggyback” fashion along with the main program. Special receivers are required to utilize these services. Analog channels may contain alternative programming, such as reading services for the blind, background music or stereo sound signals. In some extremely crowded metropolitan areas, the sub-channel program might be an alternate foreign language radio program for various ethnic groups. Sub-carriers can also transmit digital data, such as station identification, the current song’s name, web addresses, or stock quotes. In some countries, FM radios automatically re-tune themselves to the same channel in a different district by using sub-bands.
Aviation voice radios use VHF AM. AM is used so that multiple stations on the same channel can be received. (Use of FM would result in stronger stations blocking out reception of weaker stations due to FM’s capture effect). Aircraft fly high enough that their transmitters can be received hundreds of miles (or kilometres) away, even though they are using VHF.
Degen DE1103, an advanced world mini-receiver with single sideband modulation and dual conversion
Marine voice radios can use single sideband voice (SSB) in the shortwave High Frequency (HF—3 MHz to 30 MHz) radio spectrum for very long ranges or narrowband FM in the VHF spectrum for much shorter ranges. Narrowband FM sacrifices fidelity to make more channels available within the radio spectrum, by using a smaller range of radio frequencies, usually with five kHz of deviation, versus the 75 kHz used by commercial FM broadcasts, and 25 kHz used for TV sound.
Government, police, fire and commercial voice services also use narrowband FM on special frequencies. Early police radios used AM receivers to receive one-way dispatches.
Civil and military HF (high frequency) voice services use shortwave radio to contact ships at sea, aircraft and isolated settlements. Most use single sideband voice (SSB), which uses less bandwidth than AM. On an AM radio SSB sounds like ducks quacking, or the adults in a Charlie Brown cartoon. Viewed as a graph of frequency versus power, an AM signal shows power where the frequencies of the voice add and subtract with the main radio frequency. SSB cuts the bandwidth in half by suppressing the carrier and one of the sidebands. This also makes the transmitter about three times more powerful, because it doesn’t need to transmit the unused carrier and sideband.
TETRA, Terrestrial Trunked Radio is a digital cell phone system for military, police and ambulances. Commercial services such as XM, WorldSpace and Sirius offer encrypted digital Satellite radio.
[edit] Telephony
Mobile phones transmit to a local cell site (transmitter/receiver) that ultimately connects to the public switched telephone network (PSTN) through an optic fiber or microwave radio and other network elements. When the mobile phone nears the edge of the cell site’s radio coverage area, the central computer switches the phone to a new cell. Cell phones originally used FM, but now most use various digital modulation schemes. Recent developments in Sweden (such as DROPme) allow for the instant downloading of digital material from a radio broadcast (such as a song) to a mobile phone.
Satellite phones use satellites rather than cell towers to communicate.
[edit] Video
Television sends the picture as AM and the sound as AM or FM, with the sound carrier a fixed frequency (4.5 MHz in the NTSC system) away from the video carrier. Analog television also uses a vestigial sideband on the video carrier to reduce the bandwidth required.
Digital television uses 8VSB modulation in North America (under the ATSC digital television standard), and COFDM modulation elsewhere in the world (using the DVB-T standard). A Reed–Solomon error correction code adds redundant correction codes and allows reliable reception during moderate data loss. Although many current and future codecs can be sent in the MPEG transport stream container format, as of 2006 most systems use a standard-definition format almost identical to DVD: MPEG-2 video in Anamorphic widescreen and MPEG layer 2 (MP2) audio. High-definition television is possible simply by using a higher-resolution picture, but H.264/AVC is being considered as a replacement video codec in some regions for its improved compression. With the compression and improved modulation involved, a single “channel” can contain a high-definition program and several standard-definition programs.
[edit] Navigation
All satellite navigation systems use satellites with precision clocks. The satellite transmits its position, and the time of the transmission. The receiver listens to four satellites, and can figure its position as being on a line that is tangent to a spherical shell around each satellite, determined by the time-of-flight of the radio signals from the satellite. A computer in the receiver does the math.
Radio direction-finding is the oldest form of radio navigation. Before 1960 navigators used movable loop antennas to locate commercial AM stations near cities. In some cases they used marine radiolocation beacons, which share a range of frequencies just above AM radio with amateur radio operators. LORAN systems also used time-of-flight radio signals, but from radio stations on the ground. VOR (Very High Frequency Omnidirectional Range), systems (used by aircraft), have an antenna array that transmits two signals simultaneously. A directional signal rotates like a lighthouse at a fixed rate. When the directional signal is facing north, an omnidirectional signal pulses. By measuring the difference in phase of these two signals, an aircraft can determine its bearing or radial from the station, thus establishing a line of position. An aircraft can get readings from two VORs and locate its position at the intersection of the two radials, known as a “fix.” When the VOR station is collocated with DME (Distance Measuring Equipment), the aircraft can determine its bearing and range from the station, thus providing a fix from only one ground station. Such stations are called VOR/DMEs. The military operates a similar system of navaids, called TACANs, which are often built into VOR stations. Such stations are called VORTACs. Because TACANs include distance measuring equipment, VOR/DME and VORTAC stations are identical in navigation potential to civil aircraft.
[edit] Radar
Radar (Radio Detection And Ranging) detects objects at a distance by bouncing radio waves off them. The delay caused by the echo measures the distance. The direction of the beam determines the direction of the reflection. The polarization and frequency of the return can sense the type of surface. Navigational radars scan a wide area two to four times per minute. They use very short waves that reflect from earth and stone. They are common on commercial ships and long-distance commercial aircraft.
General purpose radars generally use navigational radar frequencies, but modulate and polarize the pulse so the receiver can determine the type of surface of the reflector. The best general-purpose radars distinguish the rain of heavy storms, as well as land and vehicles. Some can superimpose sonar data and map data from GPS position.
Search radars scan a wide area with pulses of short radio waves. They usually scan the area two to four times a minute. Sometimes search radars use the Doppler effect to separate moving vehicles from clutter. Targeting radars use the same principle as search radar but scan a much smaller area far more often, usually several times a second or more. Weather radars resemble search radars, but use radio waves with circular polarization and a wavelength to reflect from water droplets. Some weather radar use the Doppler effect to measure wind speeds.
[edit] Data (digital radio)
2008 Pure One Classic digital radio
Most new radio systems are digital, see also: Digital TV, Satellite Radio, Digital Audio Broadcasting. The oldest form of digital broadcast was spark gap telegraphy, used by pioneers such as Marconi. By pressing the key, the operator could send messages in Morse code by energizing a rotating commutating spark gap. The rotating commutator produced a tone in the receiver, where a simple spark gap would produce a hiss, indistinguishable from static. Spark-gap transmitters are now illegal, because their transmissions span several hundred megahertz. This is very wasteful of both radio frequencies and power.
The next advance was continuous wave telegraphy, or CW (Continuous Wave), in which a pure radio frequency, produced by a vacuum tube electronic oscillator was switched on and off by a key. A receiver with a local oscillator would “heterodyne” with the pure radio frequency, creating a whistle-like audio tone. CW uses less than 100 Hz of bandwidth. CW is still used, these days primarily by amateur radio operators (hams). Strictly, on-off keying of a carrier should be known as “Interrupted Continuous Wave” or ICW or on-off keying (OOK).
Radioteletype equipment usually operates on short-wave (HF) and is much loved by the military because they create written information without a skilled operator. They send a bit as one of two tones using frequency-shift keying. Groups of five or seven bits become a character printed by a teleprinter. From about 1925 to 1975, radioteletype was how most commercial messages were sent to less developed countries. These are still used by the military and weather services.
Aircraft use a 1200 Baud radioteletype service over VHF to send their ID, altitude and position, and get gate and connecting-flight data. Microwave dishes on satellites, telephone exchanges and TV stations usually use quadrature amplitude modulation (QAM). QAM sends data by changing both the phase and the amplitude of the radio signal. Engineers like QAM because it packs the most bits into a radio signal when given an exclusive (non-shared) fixed narrowband frequency range. Usually the bits are sent in “frames” that repeat. A special bit pattern is used to locate the beginning of a frame.
Modern GPS receivers.
Communication systems that limit themselves to a fixed narrowband frequency range are vulnerable to jamming. A variety of jamming-resistant spread spectrum techniques were initially developed for military use, most famously for Global Positioning System satellite transmissions. Commercial use of spread spectrum began in the 1980s. Bluetooth, most cell phones, and the 802.11b version of Wi-Fi each use various forms of spread spectrum.
Systems that need reliability, or that share their frequency with other services, may use “coded orthogonal frequency-division multiplexing” or COFDM. COFDM breaks a digital signal into as many as several hundred slower subchannels. The digital signal is often sent as QAM on the subchannels. Modern COFDM systems use a small computer to make and decode the signal with digital signal processing, which is more flexible and far less expensive than older systems that implemented separate electronic channels. COFDM resists fading and ghosting because the narrow-channel QAM signals can be sent slowly. An adaptive system, or one that sends error-correction codes can also resist interference, because most interference can affect only a few of the QAM channels. COFDM is used for Wi-Fi, some cell phones, Digital Radio Mondiale, Eureka 147, and many other local area network, digital TV and radio standards.
[edit] Heating
Radio-frequency energy generated for heating of objects is generally not intended to radiate outside of the generating equipment, to prevent interference with other radio signals. Microwave ovens use intense radio waves to heat food. Diathermy equipment is used in surgery for sealing of blood vessels. Induction furnaces are used for melting metal for casting, and induction hobs for cooking.
[edit] Amateur radio service
Amateur radio station with multiple receivers and transceivers
Amateur radio, also known as “ham radio”, is a hobby in which enthusiasts are licensed to communicate on a number of bands in the radio frequency spectrum non-commercially and for their own enjoyment. They may also provide emergency and public service assistance. This has been very beneficial in emergencies, saving lives in many instances.[30] Radio amateurs use a variety of modes, including nostalgic ones like Morse code and experimental ones like Low-Frequency Experimental Radio. Several forms of radio were pioneered by radio amateurs and later became commercially important, including FM, single-sideband (SSB), AM, digital packet radio and satellite repeaters. Some amateur frequencies may be disrupted by power-line internet service.
[edit] Unlicensed radio services
Unlicensed, government-authorized personal radio services such as Citizens’ band radio in Australia, the USA, and Europe, and Family Radio Service and Multi-Use Radio Service in North America exist to provide simple, (usually) short range communication for individuals and small groups, without the overhead of licensing. Similar services exist in other parts of the world. These radio services involve the use of handheld units.
Free radio stations, sometimes called pirate radio or “clandestine” stations, are unauthorized, unlicensed, illegal broadcasting stations. These are often low power transmitters operated on sporadic schedules by hobbyists, community activists, or political and cultural dissidents. Some pirate stations operating offshore in parts of Europe and the United Kingdom more closely resembled legal stations, maintaining regular schedules, using high power, and selling commercial advertising time.[31][32]
[edit] Radio control (RC)
Radio remote controls use radio waves to transmit control data to a remote object as in some early forms of guided missile, some early TV remotes and a range of model boats, cars and airplanes. Large industrial remote-controlled equipment such as cranes and switching locomotives now usually use digital radio techniques to ensure safety and reliability.
In Madison Square Garden, at the Electrical Exhibition of 1898, Nikola Tesla successfully demonstrated a radio-controlled boat.[33] He was awarded U.S. patent No. 613,809 for a “Method of and Apparatus for Controlling Mechanism of Moving Vessels or Vehicles.”[34]
Ty Pennington
Tygert Bruton “Ty” Pennington[1] (born Gary Tygert Bruton on October 19, 1964[2] in Atlanta, Georgia) is an American television host, model, philanthropist and carpenter. He is most notable for being the host of Extreme Makeover: Home Edition which currently airs on ABC in the US and Ty’s Great British Adventure, which airs on UKTV home in the UK and TV LAND http://en.wikipedia.org/wiki/Tv_land . Previously, Pennington was a carpenter on the TLC reality show Trading Spaces. Currently, he manufactures a line of furniture with the Howard Miller Company.
Early life
Tygert Pennington was born on October 19, 1964 as Gary Tygert Bruton, the second son of school psychologist Yvonne Bruton. Yvonne separated from Ty’s father when he and his older brother Wynn were very young, and spent several years as a single parent before she eventually remarried. Her new husband adopted both boys, giving them both the Pennington name. Pennington grew up in Atlanta, Georgia, primarily in his hometown of Marietta. He was also diagnosed with ADHD when he was 17.
[edit] Education
A self-described “Jack of all trades”,[3] Pennington learned woodworking early in life. His interest in home improvement started when he and several neighborhood kids built a three-story treehouse in their neighborhood, which Ty designed at the age of 12. From there, he began teaching himself about carpentry and home improvement. After attending Sprayberry High School in Marietta, Georgia, he attended Kennesaw State University, graduated from The Art Institute of Atlanta with a diploma in commercial art, and attended the Atlanta College of Art while working his way through school as a carpenter.
[edit] Career
[edit] Modeling
During his final semester, Pennington was approached by a modeling scout, and soon began a lucrative career in that field. He traveled the world and landed print jobs for J.Crew, Swatch and Sprite, and appeared in television spots for Diet Coke, Levi’s, Macy’s and Bayer, among others. His job as a model took him to places all over the world, as he went on to reside in Japan, Thailand, Italy, Canada and Germany.
[edit] Television
Pennington parlayed his hands-on skills and design acumen into a career in the entertainment industry, becoming a set designer, including for the critically acclaimed film Leaving Las Vegas in 1995. However, his professional breakthrough came through The Learning Channel‘s (now known as simply TLC) innovative hit show “Trading Spaces.” He quickly became known for his off-the-wall sense of humor and creative style during four years as the show’s playful designer and carpenter. Pennington has also taken a hand into acting as well. In 2003, he played Wilbur Wright in the independent film, The Adventures of Ociee Nash, and, in 2004, he made an appearance on the TV series Wild Card. He also appeared in country music singer Cyndi Thomson‘s music video I’m Gone.
When ABC began developing a show that would transform the homes of deserving families in seven days or less, Pennington was chosen as the leader of the eight-person design team. Extreme Makeover: Home Edition, which was originally only supposed to be a 13-part special, went on to be a huge hit, and catapulted Pennington into the mainstream even further. This led to an endorsement deal with Sears, a sponsor of the show. In the years since the show started, Pennington has been known to have fought off anything from pulled muscles to heatstroke to food poisoning to keep doing his job. Now entering into his seventh season as host and designer, Ty spends 240–260 days out of the year working on the show, and declares it to be “the greatest job in the world”. The success of Extreme Makeover: Home Edition in the UK, where it is shown on the Home channel, resulted in the channel commissioning Ty’s Great British Adventure, where Pennington worked with the community of Portreath in Cornwall to restore a run-down town park in a week. The series was shown from September 16, 2008.[4]
[edit] Other work
Prior to his partnership with Sears, Pennington was the owner and designer of his company, Furniture Unlimited, which is based in Atlanta and Los Angeles. He also lends his name to Sears, with their design team guiding the design of every item in the Ty Pennington Style line of bedding, tabletop items, bath accessories, furniture, patio furniture, and other miscellaneous home decor. In addition to his involvement in design, marketing promotions and public relations activities for Sears, Pennington is also active in community outreach through the Sears American Dream Campaign. In addition to his furniture designing, he also carries a line of hardwood flooring through Lumber Liquidators.
Pennington published the book Ty’s Tricks: Home Repair Secrets Plus Cheap and Easy Projects to Transform Any Room (2003), a do-it-yourself guide on home improvement. On May 15, 2007, he released the first issue of his quarterly magazine Ty Pennington at Home. The magazine gives his fans and avid interior designers a glimpse of his works as well as bits and pieces of his rather busy life. He has described many of his techniques and the techniques of other designers on interior design as well as answers questions sent from readers. Also includes articles from people across the country who have shared different aspects of home repair and design. Ty’s own advice articles include do’s and don’ts, choices of tools, how-to instructions on how to build custom pieces of furniture, and comparisons between glamorous interiors and identical, more budget-friendly choices of decor. Other sections include information of eco-friendly home decor items, the latest electronic gadgets to ease the process of everyday life, and even recipes set for a multitude of family meetings and social gatherings.
On July 25, 2008 Ty announced a 3 year partnership with Marketplace Events, the largest organizer of consumer remodeling, home decor and gardening shows in North America.[5] Ty will be spokesperson for the 30+ events in 25 markets.
In September 2008, Pennington became the spokesperson for Abbott Nutrition and their baby formula packaging innovation called Similac SimplePac.[6] He was also involved with the Similac Custom Nursery Design Contest and Ty’s Nursery Guide that were part of the new product marketing.
In September 2011, Pennington was on one showing of Disney’s Take Two With Phineas and Ferb.
On October 3, 2011, It was announced that Pennington will join The Revolution, which will premiere in January 2012.[7]
[edit] Personal life
[edit] Charitable work
One popular feature in his magazine is where Pennington discusses his involvement with several charities. For example, he visited Hawaii and stumbled across AccessSurfHawaii, a volunteer group which helps kids with disabilities learn to surf and play other water sports. Ty spent the day surfing with the volunteers and their kids. Afterwards, he approached the founder, Mark Marble, and said “I’ve been to Hawaii six times and this is the first time I’ve understood the true meaning of Aloha“.
He also helped Bayer Asprin, for whom he’s been an avid spokesperson, launch their first Wonders of the Heart contest, the first winners being announced in Summer 2007, and he also participated in a celebrity soccer match as part of a fundraiser for the Los Angeles Children’s Hospital, benefiting bone marrow transplant patients, which was organized by Olympic gold medalist Mia Hamm. Ty has given tours of several Hollywood homes and work places including his own, that of fellow Extreme Makeover: Home Edition designer Michael Moloney, actress Constance Zimmer, and TV talk show host and cook Rachael Ray. He shows tours of makeovers he has given to other celebrities, including Mark Stines, Extra co-host Dayna Devon (done with much assistance by Michael Moloney, and Live with Regis and Kelly co host Kelly Ripa. He has given several “Behind the Scenes” tours of Extreme Makeover: Home Edition, showing the work he and the rest of the designers and production crew carry out during the 7-day transformations of peoples’ homes and lives.
[edit] Arrest
Pennington was arrested on suspicion of DUI on May 5, 2007, at 12:35 am in Los Angeles.[8] He was released on $5,000 bail. Pennington issued an apology shortly after. It was later revealed that Pennington had a .14 blood alcohol level when he was stopped. The legal limit in California is .08.[9] Pennington said “This was my wake-up call … I also want to apologize to my fans, ABC Television and my design team for my lapse in judgment and the embarrassment I have caused.”[10]
On May 25, 2007, Pennington pleaded no contest to a charge of driving over the limit.[11] He was fined $390, received 36 months probation, 90 days suspended driver’s license, and 90 days in an alcohol treatment program, and, for community service, was required to attend a Mothers Against Drunk Driving (MADD) seminar.[11][12]
[edit] Books
- Good Design Can Change Your Life: Beautiful Rooms, Inspiring Stories, Simon & Schuster; (September 9, 2008) ISBN 978-0743294744
- Ty’s Tricks: Home Repair Secrets Plus Cheap and Easy Projects to Transform Any Room, Hyperion (2003) ISBN 1401300677
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance.[1] A minimum height specification at maturity is cited by some authors, varying from 3 m[2] to 6 m;[3] some authors set a minimum of 10 cm trunk diameter (30 cm girth).[4] Woody plants that do not meet these definitions by having multiple stems and/or small size are usually called shrubs, although many trees such as mallee do not meet such definitions.. Compared with most other plants, trees are long-lived, some reaching several thousand years old and growing to up to 115 m (379 ft) high.[5]
Trees are an important component of the natural landscape because of their prevention of erosion and the provision of a weather-sheltered ecosystem in and under their foliage. They also play an important role in producing oxygen and reducing carbon dioxide in the atmosphere, as well as moderating ground temperatures. They are also elements in landscaping and agriculture, both for their aesthetic appeal and their orchard crops (such as apples). Wood from trees is a building material, as well as a primary energy source in many developing countries. Trees also play a role in many of the world’s mythologies (see trees in mythology).[6]
Classification
A tree is a plant form that occurs in many different orders and families of plants. Most species of trees today are flowering plants (Angiosperms) and conifers. Trees show a variety of growth forms, leaf type and shape, bark characteristics and reproductive organs. For the listing of examples of well-known trees and how they are classified, see List of tree genera.
The tree form has evolved separately in unrelated classes of plants, in response to similar environmental challenges, making it a classic example of parallel evolution. With an estimate of 100,000 tree species, the number of tree species worldwide might total 25 percent of all living plant species.[7] The majority of tree species grow in tropical regions of the world and many of these areas have not been surveyed yet by botanists, making species diversity and ranges poorly understood.[8] The earliest tree-like organisms were tree ferns, horsetails and lycophytes, which grew in forests in the Carboniferous period, however these were plants were not trees, since they lacked woody tissue. Trees evolved in the Triassic period, with conifers, ginkgos, cycads and other gymnosperms appeared producing woody tissue, and were subsequently followed by tree-form flowering plants in the Cretaceous period.
A small group of trees growing together is called a grove or copse, and a landscape covered by a dense growth of trees is called a forest. Several biotopes are defined largely by the trees that inhabit them; examples are rainforest and taiga (see ecozones). A landscape of trees scattered or spaced across grassland (usually grazed or burned over periodically) is called a savanna. A forest of great age is called old growth forest or ancient woodland (in the UK). A young tree is called a sapling.
Morphology
Many trees show strong apical dominance.
The parts of a tree are the roots, trunk(s), branches, twigs and leaves. Tree stems consist mainly of support and transport tissues (xylem and phloem). Wood consists of xylem cells, and bark is made of phloem and other tissues external to the vascular cambium. Trees may be grouped into exogenous and endogenous trees according to the way in which their stem diameter increases. Exogenous trees, which comprise the great majority of trees (all conifers, and almost all broadleaf trees), grow by the addition of new wood outwards, immediately under the bark. Endogenous trees, mainly in the monocotyledons (e.g., aloes and dragon trees), grow by addition of new material as discrete bundles within the existing trunk tissue.
Trees can be identified to genus or species by a combination of the tree’s shape, and the characteristics of its bark, leaves, flowers, and fruit. The leaves may be either deciduous or evergreen.[2][3]
As an exogenous tree grows, it creates growth rings as new wood is laid down concentrically over the old wood. In species growing in areas with seasonal climate changes, wood growth produced at different times of the year may be visible as alternating light and dark, or soft and hard, rings of wood.[3] In temperate climates, and tropical climates with a single wet-dry season alternation, the growth rings are annual, each pair of light and dark rings being one year of growth; these are known as annual rings. In areas with two wet and dry seasons each year, there may be two pairs of light and dark rings each year; and in some (mainly semi-desert regions with irregular rainfall), there may be a new growth ring with each rainfall.[9] In tropical rainforest regions, with constant year-round climate, growth is continuous and the growth rings are not visible nor is there a change in the wood texture. In species with annual rings, these rings can be counted to determine the age of the tree, and used to date cores or even wood taken from trees in the past, a practice known as the science of dendrochronology. Very few tropical trees can be accurately dated in this manner. Age determination in this manner is also impossible in endogenous trees.
The roots of a tree are generally embedded in earth, providing anchorage for the above-ground biomass and absorbing water and nutrients from the soil. However, while ground nutrients are essential to a tree’s growth the majority of its biomass – over 90 percent – comes from carbon dioxide absorbed from the atmosphere (see photosynthesis).[10] Above ground, the trunk gives height to the leaf-bearing branches, aiding in competition with other plant species for sunlight. In many trees, the arrangement of the branches optimizes exposure of the leaves to sunlight.
Not all trees have all the plant organs or parts mentioned above. For example, the saguaro cactus of North America has no functional leaves. A plant form that is similar to a tree, but generally having smaller, multiple trunks and/or branches that arise near the ground, is called a shrub. However, no precise differentiation between shrubs and trees is possible. Given their small size, bonsai plants would not technically be “trees”, but one should not confuse reference to the form of a species with the size or shape of individual specimens. A spruce seedling does not fit the definition of a tree, but all spruces are trees.
Record breaking trees
The world’s champion trees can be rated on height, trunk diameter or girth, total size, and age.
Tallest trees
The heights of the tallest trees in the world have been the subject of considerable dispute and much exaggeration. Modern verified measurements with laser rangefinders, other measuring devices, or with tape drop measurements made by tree climbers (such as those carried out by canopy researchers or members of groups like the U.S. Eastern Native Tree Society), have shown that some older measuring methods and measurements are often unreliable, sometimes producing exaggerations of 5% to 15% or more above the real height. Historical claims of trees growing to 130 m (430 ft), and even 150 m (490 ft), are now largely disregarded as unreliable, and attributed to human error. Historical records of fallen trees measured prostrate on the ground are considered to be somewhat more reliable. The following are now accepted as the top ten tallest reliably measured species (taken only currently standing specimens):
- Coast Redwood (Sequoia sempervirens): 115.56 m (379.1 ft), Hyperion, Redwood National Park, California, United States[11]
- Australian Mountain-ash (Eucalyptus regnans): 99.6 m (327 ft), south of Hobart, Tasmania, Australia[12]
- Coast Douglas-fir (Pseudotsuga menziesii): 99.4 m (326 ft), Brummit Creek, Coos County, Oregon, United States[13]
- Sitka Spruce (Picea sitchensis): 96.7 m (317 ft), Prairie Creek Redwoods State Park, California, United States[14]
- Giant Sequoia (Sequoiadendron giganteum): 94.9 m (311 ft), Redwood Mountain Grove, Kings Canyon National Park, California, United States[15]
- Tasmanian Blue Gum (Eucalyptus globulus): 90.7 m (298 ft), Tasmania, Australia[16]
- Manna Gum (Eucalyptus viminalis): 89 m (292 ft), Evercreech Forest Reserve, Tasmania, Australia[16]
- Shorea faguetiana: 88.3 m (290 ft) Tawau Hills National Park, in Sabah on the island of Borneo[17]
- Alpine Ash (Eucalyptus delegatensis): 87.9 m (288 ft), Tasmania, Australia[16]
A view of a tree from below; this may exaggerate apparent height
Stoutest trees
The girth of a tree is usually much easier to measure than the height, as it is a simple matter of stretching a tape round the trunk, and pulling it taut to find the circumference. Despite this, UK tree author Alan Mitchell made the following comment about measurements of yew trees:
The aberrations of past measurements of yews are beyond belief. For example, the tree at Tisbury has a well-defined, clean, if irregular bole at least 1.5 m long. It has been found to have a girth that dilated and shrunk in the following way: 11.28 m (1834 Loudon), 9.3 m (1892 Lowe), 10.67 m (1903 Elwes and Henry), 9.0 m (1924 E. Swanton), 9.45 m (1959 Mitchell) … Earlier measurements have therefore been omitted.
As a general standard, tree girth is taken at “breast height”. This is cited as dbh (diameter at breast height) in tree and forestry literature.[3][18] Breast height is defined differently in different situations, with most forestry measurements taking girth at 1.3 m above ground,[18] while those who measure ornamental trees usually measure at 1.5 m above ground;[3] in most cases this makes little difference to the measured girth. On sloping ground, the “above ground” reference point is usually taken as the highest point on the ground touching the trunk,[3][18] but some use the average between the highest and lowest points of ground.[citation needed] Some of the inflated old measurements may have been taken at ground level. Some past exaggerated measurements also result from measuring the complete next-to-bark measurement, pushing the tape in and out over every crevice and buttress.[19]
Modern trends are to cite the tree’s diameter rather than the circumference. Diameter of the tree is calculated by finding the medium diameter of the trunk, in most cases obtained by dividing the measured circumference by π; this assumes the trunk is mostly circular in cross-section (an oval or irregular cross-section would result in a mean diameter slightly greater than the assumed circle). Accurately measuring circumference or diameter is difficult in species with the large buttresses that are especially characteristic in many species of rainforest trees. Simple measurement of circumference of such trees can be misleading when the circumference includes much empty space between buttresses.
One further problem with measuring baobabs Adansonia is that these trees store large amounts of water in the very soft wood in their trunks. This leads to marked variation in their girth over the year (though not more than about 2.5%[20]), swelling to a maximum at the end of the rainy season, minimum at the end of the dry season.
The stoutest living single-trunk species in diameter are:
- Montezuma Cypress Taxodium mucronatum: 11.62 m (38.1 ft), Árbol del Tule, Santa Maria del Tule, Oaxaca, Mexico.[21] Note though that this diameter includes buttressing; the actual idealised diameter of the area of its wood is 9.38 m (30.8 ft).[21]
- Giant Sequoia Sequoiadendron giganteum: 8.85 m (29.0 ft), General Grant tree, General Grant Grove, California, United States[22]
- Coast Redwood Sequoia sempervirens: 7.9 m (26 ft), Lost Monarch Jedediah Smith Redwoods State Park, California, United States.
- Australian Oak Eucalyptus obliqua: 6.72 m (22.0 ft)
- Australian Mountain-ash Eucalyptus regnans: 6.52 m (21.4 ft), Big Foot
- Western Redcedar Thuja plicata: 5.99 m (19.7 ft), Kalaloch Cedar, Olympic National Park
- Sitka Spruce Picea sitchensis: 5.39 m (17.7 ft), Quinalt Lake Spruce, Olympic National Park
- Kauri Agathis australis (Te Matua Ngahere): 5.33 m (17.5 ft).[23]
- Alerce Fitzroya cupressoides: 5.0 m (16.4 ft)
An additional problem lies in instances where multiple trunks (whether from an individual tree or multiple trees) grow together. The Sacred Fig is a notable example of this, forming additional “trunks” by growing adventitious roots down from the branches, which then thicken up when the root reaches the ground to form new trunks; a single Sacred Fig tree can have hundreds of such trunks.[1] The multi-stemmed Hundred Horse Chestnut was known to have a circumference of 57.9 m (190 ft) when it was measured in 1780.
Largest trees
The coniferous Coast Redwood is the tallest tree species on earth.
The largest trees in total volume are both tall and large in diameter and, in particular, hold a large diameter high up the trunk. Measurement is very complex, particularly if branch volume is to be included as well as the trunk volume, so measurements have only been made for a small number of trees, and generally only for the trunk. No attempt has ever been made to include root volume. Measuring standards vary.
The top ten species measured so far are*:
- Giant Sequoia Sequoiadendron giganteum: 1,487 m³ (52,508 cu ft), General Sherman[24]
- Coast Redwood Sequoia sempervirens: 1,203 m³ (42,500 cu ft), Lost Monarch[25]
- Montezuma Cypress Taxodium mucronatum: 750 m³ (25,000 cu ft), Árbol del Tule[26]
- Kauri Agathis australis (Tāne Mahuta): 516 m³ [27]
- Western Redcedar Thuja plicata: 500 m³ (17,650 cu ft ), Quinault Lake Redcedar[24]
- Tasmanian Blue Gum Eucalyptus globulus: 368 m³ (13,000 cu ft), Rullah Longatyle (Strong Girl, also Grieving Giant) [16]
- Australian Mountain-ash Eucalyptus regnans: 360 m³ (12,714 cu ft), Arve Big Tree[16]
- Coast Douglas-fir Pseudotsuga menziesii 349 m³ (12,320 cu ft) Red Creek Tree
- Sitka Spruce Picea sitchensis 337 m³ (11,920 cu ft) Queets Spruce[citation needed]
- Australian Oak Eucalyptus obliqua: 337 m³ (11,920 cu ft) Gothmog[16]
- Alpine Ash Eucalyptus delegatensis: 286 m³ (10,100 cu ft), located in Styx River Valley[16]
(*)This list does not take into account now dead specimens.
Oldest trees
The oldest trees are determined by growth rings, which can be seen if the tree is cut down, or in cores taken from the bark to the center of the tree. Accurate determination is only possible for trees that produce growth rings, generally those in seasonal climates. Trees in uniform non-seasonal tropical climates grow continuously and do not have distinct growth rings. It is also only possible for trees that are solid to the center. Many very old trees become hollow as the dead heartwood decays. For some of these species, age estimates have been made on the basis of extrapolating current growth rates, but the results are usually largely speculation. White (1998)[28] proposes a method of estimating the age of large and veteran trees in the United Kingdom through the correlation between a tree’s stem diameter, growth character and age.
The verified oldest measured ages are:
- Great Basin Bristlecone Pine (Methuselah) Pinus longaeva: 4,844 years[29]
- Alerce Fitzroya cupressoides: 3,622 years[29]
- Giant Sequoia Sequoiadendron giganteum: 3,266 years[29]
- Sugi Cryptomeria japonica: 3,000 years[30]
- Huon-pine Lagarostrobos franklinii: 2,500 years[29]
Other species suspected of reaching exceptional age include European Yew Taxus baccata (probably over 2,000 years[31][32]) and Western Redcedar Thuja plicata. The oldest known European Yew is the Llangernyw Yew in the Churchyard of Llangernyw village in North Wales, which is estimated to be between 4,000 and 5,000 years old.
Damage
El Grande, about 85 m (279 ft) high, the most massive (though not the tallest) Eucalyptus regnans was accidentally killed by loggers burning-off the remains of legally loggable trees (less than 85 m) that had been felled all around it.
Callus growth on beech branch following fire (heat) damage.
The two sources of tree damage are either biotic (from living sources) or abiotic (from non-living sources). Biotic sources include insects that bore into the tree, deer that rub bark off, and fungi.[33]
Abiotic sources include lightning, vehicles impacts, and construction activities. Construction activities can involve a number of damage sources, including grade changes that prevent aeration to roots, spills involving toxic chemicals such as cement or petroleum products, or severing of branches or roots.
Both damage sources can result in trees becoming dangerous, and the term “hazard trees” is commonly used by arborists, and industry groups such as power line operators. Hazard trees are trees that, due to disease or other factors, are more susceptible to falling in windstorms, or having parts of the tree fall.
Evaluating the danger a tree presents is based on a process called the Quantified Tree Risk Assessment.[34]
Assessment as to labeling a tree a hazard tree can be based on a field examination. Assessment as a result of construction activities that will damage a tree is based on three factors: severity, extent and duration. Severity relates usually to the degree of intrusion into the TPZ and resultant root loss. Extent is frequently a percentage of a factor such as canopy, roots or bark, and duration is normally based on time. Root severing is considered permanent in time.
Trees are similar to people. Both can withstand massive amounts of some types of damage and survive, but even small amounts of certain types of trauma can result in death. Arborists are very aware that established trees will not tolerate any appreciable disturbance of the root system.[35] However, lay people and construction professionals seldom recognise how easily a tree can be killed.
One reason for confusion about tree damage from construction involves the dormancy of trees during winter. Another factor is that trees may not show symptoms of damage until two years or longer after damage has occurred. For that reason, persons uneducated in arboricultural science may not correlate the actual cause and resultant effect.
Various organisations, such as the International Society of Arboriculture, the British Standards Institute and the Tree Industry Association (formerly the National Arborist Association), have long recognised the importance of construction activities that impact tree health. The impacts are important because they can result in monetary losses due to tree damage and resultant remediation or replacement costs, as well as violation of government ordinances or community or subdivision restrictions.
As a result, protocols for tree management prior to, during and after construction activities are well established, tested and refined. These basic steps are involved:
- Review of the construction plans
- Development of the related tree inventory
- Application of standard construction tree management protocols
- Assessment of potential for expected tree damages
- Development of a tree protection plan (providing for pre-, concurrent, and post construction damage prevention and remediation steps)
- Development of a tree protection plan
- Development of a remediation plan
- Implementation of tree protection zones (TPZ)
- Assessment of construction tree damage, post-construction
- Implementation of the remediation plan
Trees in culture
The tree has always been a cultural symbol. Common icons are the World tree, for instance Yggdrasil,[36] and the tree of life. The tree is often used to represent nature or the environment itself.
Tree value approximation (USA)
Studies have shown that trees contribute as much as 27% of the appraised land value in certain markets and cite the following[37] which can be extrapolated with care.
| diameter (inches) |
value (1985 US$) |
|---|---|
| 10 | $1,729 |
| 14 | $3,388 |
| 18 | $5,588 |
| 26 | $11,682 |
| 30 | $15,554 |
These most likely use diameter measured at breast height, 4.5 feet (140 cm) above ground, not the larger base diameter. A general model for any year and diameter is Value = 17.27939*(diameter^2)*1.022^(year-1985) assuming 2.2% inflation per year.[39] The right side of this equation is written to paste into Excel or Google to perform the calculation. Extrapolations from any model can vary widely, so value estimates for diameters larger than 30 inches (760 mm) may have to be capped so trees do not exceed 27% of total appraised land value.
SRI LANKA NATION TREE
This rain forest tree grows to about 30 m high and indigenous to the lower wet Zone of Sri Lanka. Remarkable Features of NA is beautiful bright Red Leaves and finally matured in to a deep green. Timber has a very hardness and durability and used to make bridges in the early times. But now not allowed for timber due to it’s religious value. It’s believed that the first visit of Buddha was to grove of a NA Tree at Miyanganaya and also the next Buddha (mithriya) will attain enlightenment under a NA tree. The flower of NA is also used in herbal medicine and preparation of perfumes, cosmetics and soaps. This was named as the National Tree in 1986.
Gall
Galls or cecidia are outgrowths on the surface of lifeforms caused by invasion by other lifeforms, such as parasites or bacterial infection. Plant galls are abnormal outgrowths[1] of plant tissues and can be caused by various parasites, from fungi and bacteria, to insects and mites. Plant galls are often highly organized structures and because of this the cause of the gall can often be determined without the actual agent being identified. This applies particularly to some insect and mite plant galls. In pathology, a gall is a raised sore on the skin, usually caused by chafing or rubbing.[2]
Causes of plant galls
[edit] Insects
Insect galls are the highly distinctive plant structures formed by some herbivorous insects as their own microhabitats. They are plant tissue which is controlled by the insect. Galls act as both the habitat and food source for the maker of the gall. The interior of a gall can contain edible nutritious starch and other tissues. Some galls act as “physiologic sinks”, concentrating resources in the gall from the surrounding plant parts.[3] Galls may also provide the insect with physical protection from predators.[4][5]
Insect galls are usually induced by chemicals injected by the larvae or the adults of the insects into the plants, and possibly mechanical damage. After the galls are formed, the larvae develop inside until fully grown, when they leave. In order to form galls, the insects must seize the time when plant cell division occurs quickly: the growing season, usually spring in temperate climates, but which is extended in the tropics.
The meristems, where plant cell division occurs, are the usual sites of galls, though insect galls can be found on other parts of the plant, such as the leaves, stalks, branches, buds, roots, and even flowers and fruits. Gall-inducing insects are usually species-specific and sometimes tissue-specific on the plants they gall.
Gall-inducing insects include gall wasps, gall midges, gall flies, aphids (such as Melaphis chinensis), and psyllids.
[edit] Fungi
One gall-inducing fungus is Cedar-apple rust. Galls are often seen in Millettia pinnata leaves and fruits. Leaf galls appear like tiny clubs; however, flower galls are globose.
It is worth noting that the fungus Ustilago esculenta associated with Zizania latifolia, a wild rice, produces an edible gall highly valued as a food source in the Zhejiang and Jiangsu provinces of China.[6]
[edit] Bacteria and viruses
Agrobacterium tumefaciens is an example of a gall-causing bacterium.
[edit] Other plants
Mistletoe can form galls on its hosts
[edit] Uses
Galls are rich in resins and tannic acid and have been used in the manufacture of permanent inks (such as iron gall ink) and astringent ointments, in dyeing, and in tanning. A high-quality ink has long been made from the Aleppo gall, found on oaks in the Middle East; it is one of a number of galls resembling nuts and called “gallnuts” or “nutgalls”. The yeast that makes lager beer possible originated in galls on Patagonian beech trees[7].
The larvae in galls are useful for a survival food and fishing bait; see the Indigenous Australian foods Bush coconut and Mulga apple. Nutgalls also produce purpurogallin.
[edit] Gallery
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Gall on a Maple leaf
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Rose bedeguar gall on a wild rose in summer.
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Oak artichoke gall (Andricus fecundator)
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Knopper gall (Andricus quercuscalicis)
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Knopper gall (Andricus quercuscalicis)
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Neuroterus albipes forma laeviusculus
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Eucalyptus leaf gall
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Andricus kollari oak gall
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Cola-nut galls (Andricus lignicola) on Pedunculate Oak
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Oak marble galls, one with a Gall fly exit hole and another with Phoma gallorum fungal attack.
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Red-pea gall (Cynips divisa) on Pedunculate oak.
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Sectioned gall showing central ‘cell’ and inquiline chamber; exit-hole and a possibly parasitised stunted gall specimen. -
Pineapple gall on Sitka Spruce caused by Adelges abietis.
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Developing Pineapple pseudocone galls on Norway Spruce
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Goldenrod Gall
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An Oak tree with multiple Oak apples.
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Oak Apples on an oak tree.
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Lime nail galls (Eriophyes tiliae tiliae)
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Gall of peach tree leaves, found at Beijing
australia
Australia (
/əˈstreɪljə/), officially the Commonwealth of Australia,[10] is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans.[N 4] It is the world’s sixth-largest country by total area. Neighbouring countries include Indonesia, East Timor, and Papua New Guinea to the north; the Solomon Islands, Vanuatu, and New Caledonia to the north-east; and New Zealand to the south-east. For at least 40,000 years[12] before European settlement in the late 18th century, Australia was inhabited by indigenous Australians,[13] who belonged to one or more of roughly 250 language groups.[14][15] After discovery by Dutch explorers in 1606, Australia’s eastern half was claimed by Great Britain in 1770 and settled through penal transportation to the colony of New South Wales from 26 January 1788. The population grew steadily in subsequent decades; the continent was explored and an additional five self-governing Crown Colonies were established. On 1 January 1901, the six colonies federated, forming the Commonwealth of Australia. Since Federation, Australia has maintained a stable liberal democratic political system which functions as a federal parliamentary democracy and constitutional monarchy. The federation comprises six states and several territories. The population of 22.7 million is heavily concentrated in the Eastern states and is highly urbanised. A highly developed country, Australia is the world’s thirteenth largest economy and has the world’s seventh-highest per capita income. Australia’s military expenditure is the world’s twelfth largest. With the second-highest human development index globally, Australia ranks highly in many international comparisons of national performance, such as quality of life, health, education, economic freedom, and the protection of civil liberties and political rights.[16] Australia is a member of the G20, OECD, WTO, APEC, UN, Commonwealth of Nations, ANZUS, and the Pacific Islands Forum.
Etymology
Pronounced [əˈstɹæɪljə, -liə] in Australian English,[17] the name Australia is derived from the Latin australis, meaning “southern”. The country has been referred to colloquially as Oz since the early 20th century.[N 5] Aussie is a common colloquial term for “Australian”. Legends of Terra Australis Incognita—an “unknown land of the South”—date back to Roman times and were commonplace in medieval geography, although not based on any documented knowledge of the continent. Following European discovery, names for the Australian landmass were often references to the famed Terra Australis. The earliest recorded use of the word Australia in English was in 1625 in “A note of Australia del Espíritu Santo, written by Master Hakluyt”, published by Samuel Purchas in Hakluytus Posthumus, a corruption of the original Spanish name Austrialia del Espíritu Santo for an island in Vanuatu.[22] The Dutch adjectival form Australische was used in a Dutch book in Batavia (Jakarta) in 1638, to refer to the newly discovered lands to the south.[23] Australia was later used in a 1693 translation of Les Aventures de Jacques Sadeur dans la Découverte et le Voyage de la Terre Australe, a 1676 French novel by Gabriel de Foigny, under the pen-name Jacques Sadeur.[24] Referring to the entire South Pacific region, Alexander Dalrymple used it in An Historical Collection of Voyages and Discoveries in the South Pacific Ocean in 1771. By the end of the 18th century, the name was being used to refer specifically to Australia, with the botanists George Shaw and Sir James Smith writing of “the vast island, or rather continent, of Australia, Australasia or New Holland” in their 1793 Zoology and Botany of New Holland,[25] and James Wilson including it on a 1799 chart.[26] The name Australia was popularised by the explorer Matthew Flinders, who pushed for it to be formally adopted as early as 1804. When preparing his manuscript and charts for his 1814 A Voyage to Terra Australis, he was persuaded by his patron, Sir Joseph Banks, to use the term Terra Australisas this was the name most familiar to the public. Flinders did so, but allowed himself the footnote:
“Had I permitted myself any innovation on the original term, it would have been to convert it to Australia; as being more agreeable to the ear, and an assimilation to the names of the other great portions of the earth.”[27]
This is the only occurrence of the word Australia in that text; but in Appendix III, Robert Brown‘s General remarks, geographical and systematical, on the botany of Terra Australis, Brown makes use of the adjectival form Australian throughout,[28]—the first known use of that form.[29] Despite popular conception, the book was not instrumental in the adoption of the name: the name came gradually to be accepted over the following ten years.[30] Lachlan Macquarie, a Governor of New South Wales, subsequently used the word in his dispatches to England, and on 12 December 1817 recommended to the Colonial Office that it be formally adopted.[31] In 1824, the Admiralty agreed that the continent should be known officially as Australia.[32]
History
Exploration by Europeans till 1812
Human habitation of the Australian continent is estimated to have begun between 42,000 and 48,000 years ago,[33] possibly with the migration of people by land bridges and short sea-crossings from what is now South-East Asia. These first inhabitants may have been ancestors of modern Indigenous Australians. At the time of European settlement in the late 18th century, most Indigenous Australians were hunter-gatherers, with a complex oral culture and spiritual values based on reverence for the land and a belief in the Dreamtime. The Torres Strait Islanders, ethnically Melanesian, were originally horticulturalists and hunter-gatherers.[34] Following sporadic visits by fishermen from the Malay Archipelago,[35] the first recorded European sighting of the Australian mainland and the first recorded European landfall on the Australian continent were attributed to the Dutch navigator Willem Janszoon. He sighted the coast of Cape York Peninsula on an unknown date in early 1606, and made landfall on 26 February at the Pennefather River on the western shore of Cape York, near the modern town of Weipa.[36] The Dutch charted the whole of the western and northern coastlines of “New Holland” during the 17th century, but made no attempt at settlement.[36] William Dampier, an English explorer and privateer landed on the north-west coast of Australia in 1688 and again in 1699 on a return trip. In 1770, James Cook sailed along and mapped the east coast of Australia, which he named New South Wales and claimed for Great Britain.[37] Cook’s discoveries prepared the way for establishment of a new penal colony. The British Crown Colony of New South Wales was formed on 26 January 1788, when Captain Arthur Phillip led the First Fleet to Port Jackson.[38] This date became Australia’s national day, Australia Day. Van Diemen’s Land, now known as Tasmania, was settled in 1803 and became a separate colony in 1825.[39] The United Kingdom formally claimed the western part of Australia in 1828.[40] Separate colonies were carved from parts of New South Wales: South Australia in 1836, Victoria in 1851, and Queensland in 1859.[41] The Northern Territory was founded in 1911 when it was excised from South Australia.[42] South Australia was founded as a “free province”—it was never a penal colony.[43] Victoria and Western Australia were also founded “free”, but later accepted transported convicts.[44][45] A campaign by the settlers of New South Wales led to the end of convict transportation to that colony; the last convict ship arrived in 1848.[46]
Port Arthur, Tasmania was Australia’s largest gaol for transported convicts.
The indigenous population, estimated at 750,000 to 1,000,000 at the time of European settlement,[47] declined steeply for 150 years following settlement, mainly due to infectious disease.[48] The “Stolen Generations” (removal of Aboriginal children from their families), which historians such as Henry Reynolds have argued could be considered genocide,[49] may have contributed to the decline in the Indigenous population.[50] Such interpretations of Aboriginal history are disputed by conservative commentators such as former Prime Minister John Howard as exaggerated or fabricated for political or ideological reasons.[51] This debate is known within Australia as the History wars.[52] The Federal government gained the power to make laws with respect to Aborigines following the 1967 referendum.[53] Traditional ownership of land—aboriginal title—was not recognised until 1992, when the High Court case Mabo v Queensland (No 2) overturned the notion of Australia as terra nullius (“land belonging to no one”) before European occupation.[54] A gold rush began in Australia in the early 1850s,[55] and the Eureka Rebellion against mining licence fees in 1854 was an early expression of civil disobedience.[56] Between 1855 and 1890, the six colonies individually gained responsible government, managing most of their own affairs while remaining part of the British Empire.[57] The Colonial Office in London retained control of some matters, notably foreign affairs,[58] defence,[59]and international shipping.
The Last Post is played at an ANZAC Day ceremony in Port Melbourne, Victoria. Similar ceremonies are held in most suburbs and towns.
On 1 January 1901 federation of the colonies was achieved after a decade of planning, consultation, and voting.[60] The Commonwealth of Australia was established and it became a dominion of the British Empire in 1907. The Federal Capital Territory (later renamed the Australian Capital Territory) was formed in 1911 as the location for the future federal capital of Canberra. Melbourne was the temporary seat of government from 1901 to 1927 while Canberra was constructed.[61] The Northern Territory was transferred from the control of the South Australian government to the federal parliament in 1911.[62] In 1914, Australia joined Britain in fighting World War I, with support from both the outgoing Liberal Party and the incoming Labor Party.[63] Australians took part in many of the major battles fought on the Western Front.[64] Of about 416,000 who served, about 60,000 were killed and another 152,000 were wounded.[65] Many Australians regard the defeat of the Australian and New Zealand Army Corps (ANZACs) at Gallipoli as the birth of the nation—its first major military action.[66][67] The Kokoda Track campaign is regarded by many as an analogous nation-defining event during World War II.[68] Britain’s Statute of Westminster 1931 formally ended most of the constitutional links between Australia and the UK. Australia adopted it in 1942,[69] but it was backdated to 1939 to confirm the validity of legislation passed by the Australian Parliament during World War II.[70][71] The shock of the UK’s defeat in Asia in 1942 and the threat of Japanese invasion caused Australia to turn to the United States as a new ally and protector.[72] Since 1951, Australia has been a formal military ally of the US, under the ANZUS treaty.[73] After World War II Australia encouraged immigration from Europe. Since the 1970s and following the abolition of the White Australia policy, immigration from Asia and elsewhere was also promoted.[74] As a result, Australia’s demography, culture, and self-image were transformed.[75] The final constitutional ties between Australia and the UK were severed with the passing of the Australia Act 1986, ending any British role in the government of the Australian States, and closing the option of judicial appeals to the Privy Council in London.[76] In a 1999 referendum, 55 per cent of Australian voters and a majority in every Australian state rejected a proposal to become a republic with a president appointed by a two-thirds vote in both Houses of the Australian Parliament. Since the election of the Whitlam Government in 1972,[77] there has been an increasing focus in foreign policy on ties with other Pacific Rim nations, while maintaining close ties with Australia’s traditional allies and trading partners.[78]
Politics
Parliament House, Canberra was opened in 1988, replacing the provisional Parliament House building opened in 1927.
Australia is a constitutional monarchy with a federal division of powers. It uses a parliamentary system of government with Queen Elizabeth II at its apex as the Queen of Australia, a role that is distinct from her position as monarch of the other Commonwealth realms. The Queen resides in the United Kingdom, and she is represented by her viceroys in Australia, (the Governor-General at the federal level and by the Governors at the state level), who by convention act on the advice of her ministers. Supereme executive authority is vested by the constitution of Australia in the sovereign, but the power to exercise it is conferred by the constitution specifically to the Governor-General.[79][80] The most notable exercise of the Governor-General’s reserve powers outside a Prime Minister’s request was the dismissal of the Whitlam Government in the constitutional crisis of 1975.[81] The federal government is separatedinto three branches:
- The legislature: the bicameral Parliament, defined in section 1 of the constitution as comprising the Queen (represented by the Governor-General), the Senate, and the House of Representatives;
- The executive: the Federal Executive Council, in practice the Governor-General as advised by the Prime Minister and Ministers of State;[82]
- The judiciary: the High Court of Australia and other federal courts, whose judges are appointed by the Governor-General on advice of the Council.
In the Senate (the upper house), there are 76 senators: twelve each from the states and two each from the mainland territories (the Australian Capital Territory and the Northern Territory).[83] The House of Representatives (the lower house) has 150 members elected from single-member electoral divisions, commonly known as “electorates” or “seats”, allocated to states on the basis of population,[84] with each original state guaranteed a minimum of five seats.[85] Elections for both chambers are normally held every three years, simultaneously; senators have overlapping six-year terms except for those from the territories, whose terms are not fixed but are tied to the electoral cycle for the lower house; thus only 40 of the 76 places in the Senate are put to each election unless the cycle is interrupted by a double dissolution.[83]
Australia’s National Flag comprises the Union Jack, the Commonwealth Star, and the Southern Cross.
Australia’s electoral system uses preferential voting for all lower house elections with the exception of Tasmania and the ACT, which, along with the Senate and most state upper houses, combine it with proportional representation in a system known as the single transferable vote. Voting is compulsory for all enrolled citizens 18 years and over in every jurisdiction,[86] as is enrolment (with the exception of South Australia).[87] Although the Prime Minister is appointed by the Governor-General, in practice the party with majority support in the House of Representatives forms government and its leader becomes Prime Minister.[citation needed] There are two major political groups that usually form government, federally and in the states: the Australian Labor Party, and the Coalition which is a formal grouping of the Liberal Party and its minor partner, the National Party.[88][89] Independent members and several minor parties—including the Greens and the Australian Democrats—have achieved representation in Australian parliaments, mostly in upper houses. Following a partyroom leadership challenge, Julia Gillard became the first female Prime Minister in June 2010.[90] The last federal election was held on 21 August 2010 and resulted in the first hung parliamentin over 50 years. Gillard was able to form a minority Labor government with the support of independents.
States and territories
A clickable map of Australia’s states and mainland territories
Australia has six states—New South Wales, Queensland, South Australia, Tasmania, Victoria, and Western Australia—and two major mainland territories—the Northern Territory and the Australian Capital Territory (ACT). In most respects these two territories function as states, but the Commonwealth Parliament can override any legislation of their parliaments. By contrast, federal legislation overrides state legislation only in areas that are set out in Section 51 of the Australian Constitution; state parliaments retain all residual legislative powers, including those over schools, state police, the state judiciary, roads, public transport, and local government, since these do not fall under the provisions listed in Section 51.[91] Each state and major mainland territory has its own parliament—unicameral in the Northern Territory, the ACT, and Queensland, and bicameral in the other states. The states are sovereign entities, although subject to certain powers of the Commonwealth as defined by the Constitution. The lower houses are known as the Legislative Assembly (the House of Assembly in South Australia and Tasmania); the upper houses are known as the Legislative Council. The head of the government in each state is the Premier, and in each territory the Chief Minister. The Queen is represented in each state by a Governor; and in the Northern Territory, the Administrator.[92] In the Commonwealth, the Queen’s representative is the Governor-General.[93] The federal parliament directly administers the following territories:[82]
- Jervis Bay Territory, a naval base and sea port for the national capital in land that was formerly part of New South Wales
- Christmas Island and Cocos (Keeling) Islands
- Ashmore and Cartier Islands
- Coral Sea Islands
- Heard Island and McDonald Islands
- Australian Antarctic Territory
Norfolk Island is also technically an external territory; however, under the Norfolk Island Act 1979 it has been granted more autonomy and is governed locally by its own legislative assembly. The Queen is represented by an Administrator, currently Owen Walsh.[94]
Foreign relations and military
Australian Army soldiers conducting a foot patrol during a joint training exercise with US forces in Shoalwater Bay (2007).
Over recent decades, Australia’s foreign relations have been driven by a close association with the United States through the ANZUS pact, and by a desire to develop relationships with Asia and the Pacific, particularly through ASEAN and the Pacific Islands Forum. In 2005 Australia secured an inaugural seat at the East Asia Summit following its accession to the Treaty of Amity and Cooperation in Southeast Asia, and in 2011 will attend the Sixth East Asia Summit in Indonesia. Australia is a member of the Commonwealth of Nations, in which the Commonwealth Heads of Government meetings provide the main forum for cooperation.[95] Australia has pursued the cause of international trade liberalisation.[96][97][98] It led the formation of the Cairns Group and Asia-Pacific Economic Cooperation.[99][100] Australia is a member of the Organisation for Economic Co-operation and Development and the World Trade Organization,[101][102] and has pursued several major bilateral free trade agreements, most recently the Australia – United States Free Trade Agreement[103] and Closer Economic Relations with New Zealand,[104] with another free trade agreement being negotiated with China—the Australia – China Free Trade Agreement—and Japan,[105] South Korea in 2011,[106][107] Australia–Chile Free Trade Agreement, ASEAN – Australia – New Zealand Free Trade Area, and the Trans-Pacific Strategic Economic Partnership. Along with New Zealand, the United Kingdom, Malaysia, and Singapore, Australia is party to the Five Power Defence Arrangements, a regional defence agreement. A founding member country of the United Nations, Australia is strongly committed to multilateralism,[108] and maintains an international aid program under which some 60 countries receive assistance. The 2005–06 budget provides A$2.5 billion for development assistance;[109] as a percentage of GDP, this contribution is less than that recommended in the UN Millennium Development Goals. Australia ranks seventh overall in the Center for Global Development‘s 2008 Commitment to Development Index.[110] Australia’s armed forces—the Australian Defence Force (ADF)—comprise the Royal Australian Navy (RAN), the Australian Army, and the Royal Australian Air Force (RAAF), in total numbering 80,561 personnel (including 55,068 regulars and 25,493 reservists).[111] The titular role of Commander-in-Chief is vested in the Governor-General, who appoints a Chief of the Defence Force from one of the armed services on the advice of the government.[112] Day-to-day force operations are under the command of the Chief, while broader administration and the formulation of defence policy is undertaken by the Minister and Department of Defence. In the 2010–11 budget, defence spending was A$25.7 billion,[113] representing the 14th largest defence budget in the world but accounting for only 1.2 per cent of global military spending.[114] Australia has been involved in UN and regional peacekeeping, disaster relief, and armed conflict; it currently has deployed approximately 3,330 defence force personnel in varying capacities to 12 overseas operations in areas including East Timor, Solomon Islands and Afghanistan.[115]
Geography and climate
Climatic zones in Australia, based on the Köppen climate classification.
Australia’s landmass of 7,617,930 square kilometres (2,941,300 sq mi)[116] is on the Indo-Australian Plate. Surrounded by the Indian[N 4] and Pacific oceans, it is separated from Asia by the Arafura and Timor seas. The world’s smallest continent[117] and sixth largest country by total area,[118] Australia—owing to its size and isolation—is often dubbed the “island continent”[119], and is sometimes considered the world’s largest island.[120] Australia has 34,218 kilometres (21,262 mi) of coastline (excluding all offshore islands),[121] and claims an extensive Exclusive Economic Zone of 8,148,250 square kilometres (3,146,060 sq mi). This exclusive economic zone does not include the Australian Antarctic Territory.[122] Excluding Macquarie Island, Australia lies between latitudes 9° and 44°S, and longitudes 112° and 154°E. The Great Barrier Reef, the world’s largest coral reef,[123] lies a short distance off the north-east coast and extends for over 2,000 kilometres (1,240 mi). Mount Augustus, claimed to be the world’s largest monolith,[124] is located in Western Australia. At 2,228 metres (7,310 ft), Mount Kosciuszko on the Great Dividing Range is the highest mountain on the Australian mainland, although Mawson Peak on the remote Australian territory of Heard Island is taller at 2,745 metres (9,006 ft).[125] Australia is the flattest continent,[126] with the oldest and least fertile soils;[127][128] desert or semi-arid land commonly known as the outback makes up by far the largest portion of land. The driest inhabited continent, only its south-east and south-west corners have a temperate climate.[129] The population density, 2.8 inhabitants per square kilometre, is among the lowest in the world,[130] although a large proportion of the population lives along the temperate south-eastern coastline.[131] Eastern Australia is marked by the Great Dividing Range that runs parallel to the coast of Queensland, New South Wales, and much of Victoria—although the name is not strictly accurate, as in parts the range consists of low hills and the highlands are typically no more than 1,600 metres (5,249 ft) in height.[132] The coastal uplands and a belt of Brigalow grasslands lie between the coast and the mountains, while inland of the dividing range are large areas of grassland.[132][133] These include the western plains of New South Wales, and the Einasleigh Uplands, Barkly Tableland, and Mulga Lands of inland Queensland. The northern point of the east coast is the tropical rainforested Cape York Peninsula.[134][135][136][137]
Topographic map of Australia
The landscapes of the northern part of the country—the Top End and the Gulf Country behind the Gulf of Carpentaria, with their tropical climate—consist of woodland, grassland, and desert.[138][139][140] At the north-west corner of the continent are the sandstone cliffs and gorges of The Kimberley, and below that the Pilbara. South and inland of these lie more areas of grassland: the Ord Victoria Plain and the Western Australian Mulga shrublands.[141][142][143] At the heart of the country are the uplands of central Australia; prominent features of the centre and south include the inland Simpson, Tirari and Sturt Stony, Gibson, Great Sandy, Tanami, and Great Victoria deserts, with the famous Nullarbor Plain on the southern coast.[144][145][146][147] The climate of Australia is significantly influenced by ocean currents, including the Indian Ocean Dipole and the El Niño-Southern Oscillation, which is correlated with periodic drought, and the seasonal tropical low pressure system that produces cyclones in northern Australia.[148][149] These factors induce rainfall to vary markedly from year to year. Much of the northern part of the country has a tropical predominantly summer rainfall (monsoon) climate.[150] Just under three quarters of Australia lies within a desert or semi-arid zone.[151] The southwest corner of the country has a Mediterranean climate.[152] Much of the southeast (including Tasmania) is temperate.[150]
Environment
The koala and the eucalyptus form an iconic Australian pair
Although most of Australia is semi-arid or desert, it includes a diverse range of habitats from alpine heaths to tropical rainforests, and is recognised as a megadiverse country. Because of the continent’s great age, extremely variable weather patterns, and long-term geographic isolation, much of Australia’s biota is unique and diverse. About 85 per cent of flowering plants, 84 per cent of mammals, more than 45 per cent of birds, and 89 per cent of in-shore, temperate-zone fish are endemic.[153] Australia has the greatest number of reptiles of any country, with 755 species.[154] Australian forests are mostly made up of evergreen species, particularly eucalyptus trees in the less arid regions, wattles replace them in drier regions and deserts as the most dominant species.[155] Among well-known Australian fauna are the monotremes (the platypus and echidna); a host of marsupials, including the kangaroo, koala, and wombat, and birds such as the emu and the kookaburra.[155] Australia is home to many dangerous animals including some of the most venomous snakes in the world.[156] The dingo was introduced by Austronesian people who traded with Indigenous Australians around 3000 BCE.[157] Many plant and animal species became extinct soon after first human settlement,[158] including the Australian megafauna; others have disappeared since European settlement, among them the thylacine.[159][160] Many of Australia’s ecoregions, and the species within those regions, are threatened by human activities and introduced plant and animal species.[161] The federal Environment Protection and Biodiversity Conservation Act 1999 is the legal framework for the protection of threatened species.[162] Numerous protected areas have been created under the National Strategy for the Conservation of Australia’s Biological Diversity to protect and preserve unique ecosystems;[163][164] 65 wetlands are listed under the Ramsar Convention,[165] and 16 natural World Heritage Sites have been established.[166] Australia was ranked 51st of 163 countries in the world on the 2010 Environmental Performance Index.[167] Climate change has become an increasing concern in Australia in recent years,[168] with many Australians considering protection of the environment to be the most important issue facing the country.[169] The Rudd Ministry has initiated several emission reduction activities;[170] Rudd’s first official act, on his first day in office, was to sign the instrument of ratification of the Kyoto Protocol. Nevertheless, Australia’s carbon dioxide emissions per capita are among the highest in the world, lower than those of only a few other industrialised nations.[171] Rainfall in Australia has slightly increased over the past century, both nationwide and for two quadrants of the nation,[172] while annual mean temperatures increased significantly over the past decades.[173] Water restrictions are frequently in place in many regions and cities of Australia in response to chronic shortages due to urban population increases and localised drought.[174][175]
Economy
The Super Pit gold mine in Kalgoorlie, Australia’s largest open cut mine.[176]
Australia has a market economy with high GDP per capita and low rate of poverty. The Australian dollar is the currency for the nation, including Christmas Island, Cocos (Keeling) Islands, and Norfolk Island, as well as the independent Pacific Island states of Kiribati, Nauru, and Tuvalu. After the 2006 merger of the Australian Stock Exchange and the Sydney Futures Exchange, the Australian Securities Exchange is now the ninth largest in the world.[177] Ranked third in the Index of Economic Freedom (2010),[178] Australia is the world’s thirteenth largest economy and has the ninth highest per capita GDP; higher than that of the United Kingdom, Germany, France, Canada, Japan, and the United States. The country was ranked second in the United Nations 2010 Human Development Index and first in Legatum‘s 2008 Prosperity Index.[9] All of Australia’s major cities fare well in global comparative livability surveys;[179] Melbourne reached first place on The Economist’s 2011 World’s Most Livable Cities list, followed by Sydney, Perth, and Adelaide in sixth, eighth, and ninth place respectively.[180] Total government debt in Australia is about $190 billion.[181] Australia has among the highest house prices and some of the highest household debt levels in the world.[182]
Destination and value of Australian exports in 2006[183]
An emphasis on exporting commodities rather than manufactured goods has underpinned a significant increase in Australia’s terms of trade since the start of the century, due to rising commodity prices. Australia has a balance of payments that is more than 7 per cent of GDP negative, and has had persistently large current account deficits for more than 50 years.[184] Australia has grown at an average annual rate of 3.6 per cent for over 15 years, in comparison to the OECD annual average of 2.5 per cent.[184] There are differing opinions based on evidence as to whether or not Australia had been one of the few OECD nations to avoid experiencing a recession during the late 2000s global financial downturn.[185][185][186] Six of Australia’s major trading partners had been in recession which in turn affected Australia, and economic growth was hampered significantly over recent years.[187][188] The Hawke Government floated the Australian dollar in 1983 and partially deregulated the financial system.[189] The Howard Government followed with a partial deregulation of the labour market and the further privatisation of state-owned businesses, most notably in the telecommunications industry.[190] The indirect tax system was substantially changed in July 2000 with the introduction of a 10 per cent Goods and Services Tax (GST).[191] In Australia’s tax system, personal and company income tax are the main sources of government revenue.[192] In July 2011, there were 11,450,500 people employed, with an unemployment rate of 5.1 per cent.[193] Youth unemployment (15–24) rose from 8.7 per cent to 9.7 per cent over 2008–2009.[194] Over the past decade, inflation has typically been 2–3 per cent and the base interest rate 5–6 per cent. The service sector of the economy, including tourism, education, and financial services, accounts for about 70 per cent of GDP.[195] Rich in natural resources, Australia is a major exporter of agricultural products, particularly wheat and wool, minerals such as iron-ore and gold, and energy in the forms of liquified natural gas and coal. Although agriculture and natural resources account for only 3 per cent and 5 per cent of GDP respectively, they contribute substantially to export performance. Australia’s largest export markets are Japan, China, the US, South Korea, and New Zealand.[196] Australia is the world’s fourth largest exporter of wine, in an industry contributing $5.5 billion per annum to the nation’s economy.[197]
Demography
| Historic population (Estimated) [198] | ||
|---|---|---|
| Year | Indigenous population | |
| pre 1788 | 750,000 to 1,000,000 [47] | |
| Year | Non Indigenous population | Annual increase % |
| 1788 | 900 | — |
| 1800 | 5,200 | 14.6% |
| 1850 | 405,400 | 8.7% |
| Year | Total population | Annual increase % |
| 1900 | 3,765,300 | — |
| 1910 | 4,525,100 | 1.8% |
| 1920 | 5,411,000 | 1.8% |
| 1930 | 6,501,000 | 1.8% |
| 1940 | 7,078,000 | 0.9% |
| 1950 | 8,307,000 | 1.6% |
| 1960 | 10,392,000 | 2.2% |
| 1970 | 12,663,000 | 2.0% |
| 1980 | 14,726,000 | 1.5% |
| 1990 | 17,169,000 | 1.5% |
| 2000 | 19,169,100 | 1.1% |
| 2010 | 20,971,000 | 0.9% |
For generations, the vast majority of immigrants came from the British Isles, and the people of Australia are still mainly of British or Irish ethnic origin. In the 2006 Australian census, the most commonly nominated ancestry was Australian (37.13 per cent),[199] followed by English (32 per cent), Irish (9 per cent), Scottish (8 per cent), Italian (4 per cent), German (4 per cent), Chinese (3 per cent), and Greek (2 per cent).[200] Australia’s population has quadrupled since the end of World War I,[201] much of the increase from immigration. Following World War II and through to 2000, almost 5.9 million of the total population settled in the country as new immigrants, meaning that nearly two out of every seven Australians were born overseas.[202] Most immigrants are skilled,[203] but the immigration quota includes categories for family members and refugees.[203] By 2050, Australia’s population is currently projected to reach around 42 million.[204] In 2001, 23.1 per cent of Australians were born overseas; the five largest immigrant groups were those from the United Kingdom, New Zealand, Italy, Vietnam, and China.[196][205] Following the abolition of the White Australia policy in 1973, numerous government initiatives have been established to encourage and promote racial harmony based on a policy of multiculturalism.[206] In 2005–06, more than 131,000 people emigrated to Australia, mainly from Asia and Oceania.[207] The migration target for 2010–11 is 168,700, compared to 67,900 in 1998–99.[208] The Indigenous population—mainland Aborigines and Torres Strait Islanders—was counted at 410,003 (2.2 per cent of the total population) in 2001, a significant increase from 115,953 in the 1976 census.[209] A large number of Indigenous people are not identified in the Census due to undercount and cases where their Indigenous status is not recorded on the form; after adjusting for these factors, the ABS estimated the true figure for 2001 to be around 460,140 (2.4 per cent of the total population).[210] Indigenous Australians experience higher than average rates of imprisonment and unemployment,[211] lower levels of education, and life expectancies for males and females that are 11–17 years lower than those of non-indigenous Australians.[196][212][213] Some remote Indigenous communities have been described as having “failed state“-like conditions.[214][215][216][217][218] In common with many other developed countries, Australia is experiencing a demographic shift towards an older population, with more retirees and fewer people of working age. In 2004, the average age of the civilian population was 38.8 years.[219] A large number of Australians (759,849 for the period 2002–03)[220]live outside their home country.
| Largest populated areas in Australia (June 2010 Australian Bureau of Statistics estimate)[221] | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Rank | City Name | State | Pop. | Rank | City Name | State | Pop. | view · talk · edit Sydney  Melbourne |
|||
| 1 | Sydney | NSW | 4,575,532 | 11 | Greater Hobart | TAS | 214,705 | ||||
| 2 | Melbourne | VIC | 4,077,036 | 12 | Geelong | VIC | 178,650 | ||||
| 3 | Brisbane | QLD | 2,043,185 | 13 | Townsville | QLD | 172,316 | ||||
| 4 | Perth | WA | 1,696,065 | 14 | Cairns | QLD | 150,920 | ||||
| 5 | Adelaide | SA | 1,203,186 | 15 | Toowoomba | QLD | 131,258 | ||||
| 6 | Gold Coast–Tweed | QLD / NSW | 591,473 | 16 | Darwin | NT | 127,532 | ||||
| 7 | Newcastle | NSW | 546,788 | 17 | Launceston | TAS | 106,153 | ||||
| 8 | Canberra–Queanbeyan | ACT / NSW | 410,419 | 18 | Albury–Wodonga | NSW / VIC | 106,052 | ||||
| 9 | Wollongong | NSW | 292,190 | 19 | Ballarat | VIC | 96,097 | ||||
| 10 | Sunshine Coast | QLD | 251,081 | 20 | Bendigo | VIC | 91,713 | ||||
Language
Nearly three quarters of Australians live in metropolitan cities and coastal areas. The beach is an integral part of the Australian identity.[222]
The Barossa Valley is a wine-producing region in South Australia. Fewer than 15 per cent of Australians live in rural areas.
Although Australia has no official language, English is so entrenched that it has become the de facto national language.[2] Australian English is a major variety of the language with a distinctive accent and lexicon. Grammar and spelling are similar to that of British English with some notable exceptions.[223] According to the 2006 census, English is the only language spoken in the home for close to 79 per cent of the population. The next most common languages spoken at home are Italian (1.6 per cent), Greek (1.3 per cent) and Cantonese (1.2 per cent);[224] a considerable proportion of first- and second-generation migrants are bilingual. A 2010–2011 study by the Australia Early Development Index found that the most common language spoken by children after English was Arabic, followed by Vietnamese, Greek, Chinese, and Hindi.[225] Between 200 and 300 Indigenous Australian languages are thought to have existed at the time of first European contact, of which only about 70 have survived. Many of these are exclusively spoken by older people; only 18 Indigenous languages are still spoken by all age groups.[226] At the time of the 2006 Census, 52,000 Indigenous Australians, representing 12 per cent of the Indigenous population, reported that they spoke an Indigenous language at home.[227] Australia has a sign language known as Auslan, which is the main language of about 5,500 deaf people.[228]
Religion
Australia has no state religion. In the 2006 census, 64 per cent of Australians listed themselves as Christian, including 26 per cent as Roman Catholic and 19 per cent as Anglican. About 19 per cent of the population cited “No religion” (which includes humanism, atheism, agnosticism and rationalism), which was the fastest-growing group from 2001 to 2006, and a further 12 per cent did not answer (the question is optional) or did not give a response adequate for interpretation. The largest non-Christian religion in Australia is Buddhism (2.1 per cent), followed by Islam (1.7 per cent), Hinduism (0.8 per cent) and Judaism (0.5 per cent). Overall, fewer than 6 per cent of Australians identify with non-Christian religions.[229] Weekly attendance at church services in 2004 was about 1.5 million: about 7.5 per cent of the population.[230] An international survey, made by the private, not-for profit German think-tank, the Bertelsmann Foundation, found that “Australia is one of the least religious nations in the western world, coming in 17th out of 21 [countries] surveyed” and that “Nearly three out of four Australians say they are either not at all religious or that religion does not play a central role in their lives.”.[231] A survey of 1,718 Australians by the Christian Research Association at the end of 2009 suggested that the numbers of people attending religious services per month in Australia has dropped from 23 per cent in 1993 to 16 per cent in 2009, and while 60 per cent of 15 to 29-year-old respondents in 1993 identified with Christian denominations, 33 per cent did in 2009.[232]
Education
School attendance is compulsory throughout Australia. All children receive 11 years of compulsory education from the age of 6 to 16 (Year 1 to 10),[233] before they can undertake two more years (Years 11 and 12), contributing to an adult literacy rate that is assumed to be 99 per cent. A preparatory year prior to Year 1, although not compulsory, is almost universally undertaken.[233] In the Programme for International Student Assessment, Australia regularly scores among the top five of thirty major developed countries (member countries of the Organisation for Economic Co-operation and Development). Government grants have supported the establishment of Australia’s 38 universities; all but one is public.[citation needed] OECD places Australia as among the most expensive nations to attend university.[234] There is a state-based system of vocational training, known as TAFE Institutes, and many trades conduct apprenticeships for training new tradespeople.[235] Approximately 58 per cent of Australians aged from 25 to 64 have vocational or tertiary qualifications,[196] and the tertiary graduation rate of 49 per cent is the highest among OECD countries. The ratio of international to local students in tertiary education in Australia is the highest in the OECD countries.[236]
Health
Life expectancy in Australia in 2006 was 78.7 years for males and 83.5 years for females.[237] Australia has the highest rates of skin cancer in the world,[238] while cigarette smoking is the largest preventable cause of death and disease.[239] Australia has one of the highest proportions of overweight citizens among developed nations.[240]
Total expenditure on health (including private sector spending) is around 9.8 per cent of GDP.[241] Australia introduced universal health care in 1975.[242] Known as Medicare it is now nominally funded by an income tax surcharge known as the Medicare levy, currently set at 1.5 per cent.[243] The states manage hospitals and attached outpatient services, while the Commonwealth funds the Pharmaceutical Benefits Scheme (reducing the costs of medicines) and general practice.[242]
Culture
The Royal Exhibition Building in Melbourne was the first building in Australia to be listed as a UNESCO World Heritage Site in 2004[244]
Since 1788, the basis of Australian culture has been strongly influenced by Anglo-Celtic Western culture.[245][246] Distinctive cultural features have also arisen from Australia’s natural environment and Indigenous cultures.[247][248] Since the mid-20th century, American popular culture has strongly influenced Australia, particularly through television and cinema.[249] Other cultural influences come from neighbouring Asian countries, and through large-scale immigration from non-English-speaking nations.[249][250]
Arts
Sunlight Sweet by Australian landscape artist Arthur Streeton.
Australian visual arts are thought to have begun with the cave and bark paintings of its Indigenous peoples. The traditions of Indigenous Australians are largely transmitted orally, through ceremony and the telling of Dreamtime stories.[251] From the time of European settlement, a theme in Australian art has been the natural landscape,[247] seen for example in the works of Albert Namatjira,[252] Arthur Streeton and others associated with the Heidelberg School,[247] and Arthur Boyd.[253] The country’s landscape remains a source of inspiration for Australian modernist artists; it has been depicted in acclaimed works by the likes of Sidney Nolan,[254] Fred Williams,[255] Sydney Long,[256] and Clifton Pugh.[257] Australian artists influenced by modern American and European art include cubist Grace Crowley,[258] surrealist James Gleeson,[259] and pop artist Martin Sharp.[260] Contemporary Indigenous Australian art is the only art movement of international significance to emerge from Australia[261][262] and “the last great art movement of the 20th century”;[263] its exponents have included Emily Kngwarreye.[264][265] Art critic Robert Hughes has written several influential books about Australian history and art, and was described as the “world’s most famous art critic” by The New York Times.[266] The National Gallery of Australia and state galleries maintain Australian and overseas collections.[267]
Many of Australia’s performing arts companies receive funding through the federal government’s Australia Council.[268] There is a symphony orchestra in each state,[269] and a national opera company, Opera Australia,[270] well-known for its famous soprano Joan Sutherland.[271] At the start of the 20th century, Nellie Melba was one of the world’s leading opera singers.[272] Ballet and dance are represented by The Australian Ballet and various state companies. Each state has a publicly funded theatre company.[273][274][275]
Performance of Aboriginal song and dance in the Australian National Maritime Museum in Sydney
Australian literature has also been influenced by the landscape; the works of writers such as Banjo Paterson, Henry Lawson, and Dorothea Mackellar captured the experience of the Australian bush.[276] The character of the nation’s colonial past, as represented in early literature, is popular with modern Australians.[247] In 1973, Patrick White was awarded the Nobel Prize in Literature,[277] the first Australian to have achieved this.[278] Australian winners of the Man Booker Prize have included Peter Carey and Thomas Keneally;[279] David Williamson, David Malouf, and J. M. Coetzee, who recently became an Australian citizen, are also renowned writers,[280] and Les Murray is regarded as “one of the leading poets of his generation”.[281]
Media
The Australian cinema industry began with the 1906 release of The Story of the Kelly Gang, which is regarded as being the world’s first feature-length film;[282] but both Australian feature film production and the distribution of British-made features declined dramatically after World War I as American studios and distributors monopolised the industry,[283] and by the 1930s around 95 per cent of the feature films screened in Australia were produced in Hollywood. By the late 1950s feature film production in Australia had effectively ceased and there were no all-Australian feature films made in the decade between 1959 and 1969.[284] Thanks to initiatives by the Gorton and Whitlam federal governments, the New Wave of Australian cinema of the 1970s brought provocative and successful films, some exploring the nation’s colonial past, such as Picnic at Hanging Rock and Breaker Morant,[285] while the so-called “Ocker” genre produced several highly successful urban-based comedy features including The Adventures of Barry McKenzie and Alvin Purple.[286][287][288] Later hits included Mad Max and Gallipoli.[289][290] More recent successes included Shine and Rabbit-Proof Fence.[291][292] Notable Australian actors include Judith Anderson,[293] Errol Flynn,[294] Nicole Kidman, Hugh Jackman, Heath Ledger, Geoffrey Rush, and Cate Blanchett—current joint director of the Sydney Theatre Company.[295][296] Australia has two public broadcasters (the Australian Broadcasting Corporation and the multicultural Special Broadcasting Service), three commercial television networks, several pay-TV services,[297] and numerous public, non-profit television and radio stations. Each major city has at least one daily newspaper,[297] and there are two national daily newspapers, The Australian and The Australian Financial Review.[297] In 2010, Reporters Without Borders placed Australia 18th on a list of 178 countries ranked by press freedom, behind New Zealand (8th) but ahead of the United Kingdom (19th) and United States (20th).[298] This relatively low ranking is primarily because of the limited diversity of commercial media ownership in Australia;[299] most print media are under the control of News Corporation and Fairfax Media.[300]
Cuisine
The food of Indigenous Australians was largely influenced by the area in which they lived. Most tribal groups subsisted on a simple hunter-gatherer diet, hunting native game and fish and collecting native plants and fruit. The general term for native Australian flora and fauna used as a source of food is bush tucker.[301][302] The first settlers introduced British food to the continent[303] which much of what is now considered typical Australian food is based on the Sunday roast has become an enduring tradition for many Australians.[304] Since the beginning of the 20th century, food in Australia has increasingly been influenced by immigrants to the nation, particularly from Southern European and Asian cultures.[303][304] Australian wine is produced in 60 distinct production areas totaling approximately 160,000 hectares, mainly in the southern, cooler parts of the country. The wine regions in each of these states produce different wine varieties and styles that take advantage of local climates and soil types. The predominant varieties are Shiraz, Cabernet Sauvignon, Chardonnay, Merlot, Sémillon, Pinot noir, Riesling, and Sauvignon blanc.[305][306][307][197][308][309] In 1995, an Australian red wine, Penfolds Grange, won the Wine Spectator award for Wine of the Year, the first time a wine from outside France or California achieved this distinction.[310]
Sport
Around 24 per cent Australians over the age of 15 regularly participate in organised sporting activities in Australia.[196] Australia has strong international teams in cricket, field hockey, netball, rugby league, and rugby union, having been Olympic or world champions at least twice in each sport in the last 25 years for both men and women where applicable.[312][313][314][315][316][317][318][319] Australia is also powerful in track cycling, rowing, and swimming, having consistently been in the top-five medal-winners at Olympic or World Championship level since 2000.[320][321][322] Swimming is the strongest of these sports; Australia is the second-most prolific medal winner in the sport in Olympic history.[323][324][325] Some of Australia’s most internationally well-known and successful sportspeople are swimmers Dawn Fraser, Murray Rose, Shane Gould, and Ian Thorpe; sprinters Shirley Strickland, Betty Cuthbert, and Cathy Freeman;[326] tennis players Rod Laver, Roy Emerson, Ken Rosewall, Evonne Goolagong, and Margaret Court; cricketers Donald Bradman and Shane Warne; three-time Formula One world champion Jack Brabham; five-time motorcycle grand prix world champion Mick Doohan; golfers Greg Norman and Karrie Webb;[327] cyclist Hubert Opperman; and prodigious billiards player Walter Lindrum.[328] Nationally, other popular sports include Australian rules football, horse racing, squash, surfing, soccer, and motor racing. The annual Melbourne Cup horse race and the Sydney to Hobart yacht race attract intense interest. Australia has participated in every summer Olympics of the modern era,[329] and every Commonwealth Games.[330] Australia hosted the 1956 Summer Olympics in Melbourne and the 2000 Summer Olympics in Sydney,[331] and has ranked among the top six medal-takers since 2000.[332] Australia has also hosted the 1938, 1962, 1982, and 2006 Commonwealth Games.[333] Other major international events held in Australia include the Australian Open tennis grand slam tournament, international cricket matches, and the Australian Formula One Grand Prix. Sydney hosted the 2003 Rugby World Cup and the annual Australia–New Zealand Bledisloe Cup is keenly watched. The highest-rating television programs include sports telecasts such as the summer Olympics, FIFA World Cup, Rugby League State of Origin, and the grand finals of the National Rugby League and Australian Football League.[334] Skiing in Australia began in the 1860s and snow sports take place in the Australian Alps and parts of Tasmania.
Kanad
It has been claimed that Kashyapa, later known as Kanada (Sanskrit: कणाद; also transliterated as Canada as well as other forms) was a Hindu sage and philosopher who founded the philosophical school of Vaisheshika. [1] He talked of Dvyanuka (biatomic molecule) and tryanuka (triatomic molecule).[citation needed] He probably lived around the 2nd century BCE,[2] while other sources claim he lived in the 6th Century BC. [3] [4] It is believed that he was born in Prabhas Kshetra (near Dwaraka) in Gujarat, India.
His primary area of study was Rasavādam, considered to be a type of alchemy. He is said to have believed that all living beings are composed of five elements: water, fire, earth, air, ether. Vegetables have only water, insects have water and fire, birds have water, fire, earth and air, and Humans, the top of the creation, have ether—the sense of discrimination (time, space, mind) are one. He theorized that Gurutva was responsible for the falling of objects on the Earth.
Many believe that Kanada originated the concept of atom. An interesting story states that this theory occurred to him while he was walking with food in his hand. As he nibbled at the food in his hand, throwing away the small particles, it occurred to him that he could not divide the food into further parts and thus the idea of a matter which cannot be divided further came into existence. He called that indivisible matter anu, i.e. atom.
Adherents of the school of philosophy founded by Kanada considered the atom to be indestructible, and hence eternal. They believed atoms to be minute objects invisible to the naked eye which come into being and vanish in an instant. This Indian concept of the atom was developed independently[5] and possibly prior (depending on which dates one accepts for the life of Kanada) to the development of the idea in the Greco-Roman world. Indian theories about the atom are greatly abstract and enmeshed in philosophy as they were based on logic and not on personal experience or experimentation. Thus the Indian theories lacked an empirical base, but in the words of A.L. Basham, the veteran Australian Indologist “they were brilliant imaginative explanations of the physical structure of the world, and in a large measure, agreed with the discoveries of modern physics.”[6]
According to author Dilip M. Salwi, “if Kanada’s sutras are analysed, one would find that his atomic theory was far more advanced than those forwarded later by the Greek philosophers, Leucippus and Democritus.”[7]
Netbal
Netball is a ball sport played between two teams of seven players. Its development, derived from early versions of basketball, began in England in the 1890s. By 1960 international playing rules had been standardised for the game, and the International Federation of Netball and Women’s Basketball (later renamed the International Federation of Netball Associations (IFNA)) was formed. As of 2011, IFNA comprises more than 60 national teams organized into five global regions.
Games are played on a rectangular court with raised goal rings at each end. Each team attempts to score goals by passing a ball down the court and shooting it through its goal ring. Players are assigned specific positions, which define their roles within the team and restrict their movement to certain areas of the court. During general play, a player with the ball can hold onto it for only three seconds before shooting for a goal or passing to another player. The winning team is the one that scores the most goals. Netball games are 60 minutes long. Variations have been developed to increase the game’s pace and appeal to a wider audience.
Netball is most popular in Commonwealth nations, specifically in schools, and is predominantly played by women. According to the IFNA, netball is played by more than 20 million people in more than 80 countries. Major transnational competitions take place, including the Netball Superleague in Great Britain and the ANZ Championship in Australia and New Zealand. Three major competitions take place internationally: the quadrennial World Netball Championships, the Commonwealth Games, and the yearly World Netball Series. In 1995 netball became an International Olympic Committee recognised sport.
History
Women in England playing netball on a grass court, 1910
Netball emerged from early versions of basketball and evolved into its own sport as the number of women participating in sports increased. Basketball was invented in 1891 by James Naismith in the United States. The game was initially played indoors between two teams of nine players, using an association football ball that was thrown into closed-end peach baskets.[12] Naismith’s game spread quickly across the United States and variations of the rules soon emerged. Physical Education instructor Senda Berenson developed modified rules for women in 1892; these eventually gave rise to women’s basketball. Around this time separate intercollegiate rules were developed for men and women.[13] The various basketball rules converged into a universal set in the United States.
Martina Bergman-Österberg introduced a version of basketball in 1893 to her female students at the Physical Training College in Hampstead, London.[14] The rules of the game were modified at the college over several years: the game moved outdoors and was played on grass; the baskets were replaced by rings that had nets; and in 1897 and 1899, rules from women’s basketball in the United States were incorporated.[13][15] Madame Österberg’s new sport acquired the name “net ball”.[16] The first codified rules of netball were published in 1901 by the Ling Association, later the Physical Education Association of the United Kingdom.[11][17] From England, netball spread to other countries in the British Empire. Variations of the rules and even names for the sport arose in different areas: “women’s (outdoor) basketball” arrived in Australia around 1900 and in New Zealand from 1906,[11][18] while “netball” was being played in Jamaican schools by 1909.[19]
A goal is scored at a women’s netball game in New Zealand, circa 1920s.
From the start, netball was viewed as an appropriate sport for women to play, with restricted movement that appealed to contemporary notions of women’s participation in sports, while remaining distinct from potential rival male sports.[11][20] Netball became a popular women’s sport in countries where it was introduced and spread rapidly through school systems. School leagues and domestic competitions emerged during the first half of the 20th century,[21][22] and in 1924 the first national governing body was established in New Zealand.[18] International competition was initially hampered by a lack of funds and varying rules in different countries. Australia hosted New Zealand in the first international game of netball in Melbourne on 20 August 1938; Australia won 40–11.[18] Efforts began in 1957 to standardise netball rules globally: by 1960 international playing rules had been standardised, and the International Federation of Netball and Women’s Basketball, later the International Federation of Netball Associations (IFNA), was formed to administer the sport worldwide.[23]
Representatives from England, Australia, New Zealand, South Africa, and the West Indies were part of a 1960 meeting in Sri Lanka that standardised the rules for the game.[24] The game spread to other African countries in the 1970s.[25][26] South Africa was prohibited from competing internationally from 1969 to 1994 due to apartheid.[27][28] In the United States, Netball’s popularity also increased during the 1970s, particularly in the New York area, and the United States of America Netball Association was created in 1992.[29] The game also became popular in the Pacific Island nations of the Cook Islands, Fiji and Samoa during the 1970s.[30] Even though netball was played in Sri Lanka as early as 1926, an official governing body was not created there until 1972.[31] Netball Singapore was created in 1962,[32] and the Malaysian Netball Association was created in 1978.[33]
In Australia, the term women’s basketball was used to refer to both netball and basketball.[34] During the 1950s and 1960s, a movement arose to change the Australian name of the game from women’s basketball to netball in order to avoid confusion between the two sports. The Australian Basketball Union offered to pay the costs involved to alter the name, but the netball organisation rejected the change.[34] In 1970 the Council of the All Australia Netball Association officially changed the name to “netball” in Australia.[11]
In 1963, the first international tournament was held in Eastbourne, England. Originally called the World Tournament, it later became known as the World Netball Championships.[35] Following the first tournament, one of the organisers, Miss R. Harris, declared,
England could learn from the mistakes in the past from the empty stands at Eastbourne. To get the right publicity and the right status desired, the game must emerge from the school playground. Netball should be part of a sports centre where social events could also be held.[35]
The World Netball Championships have been held every four years since, most recently in 2011. The World Youth Netball Championships started in Canberra in 1988, and have been held roughly every four years since. In 1995, the International Olympic Committee designated netball as an Olympic recognised sport.[11] Three years later it debuted at the 1998 Commonwealth Games in Kuala Lumpur.[23] Other international competitions also emerged in the late 20th century, including the Nations Cup and the Asian Netball Championship.[31]
[edit] Gender
Men and women play together during a mixed netball game in Australia.
As of 2006, the IFNA recognises only women’s netball.[36] Men’s netball teams exist in some areas but attract less attention from sponsors and spectators.[37] Men’s netball started to become popular in Australia during the 1980s, and the first men’s championship was held in 1985.[36] In 2004, New Zealand and Fiji sent teams to compete in the Australian Mixed and Men’s National Championships.[36] By 2006, mixed netball teams in Australia had as many male participants as rugby union.[38][39] Other countries with men’s national teams include Canada, Fiji, Jamaica, Kenya, Pakistan and the United Arab Emirates.[40] Unlike women’s netball at elite and national levels, men’s and mixed gendered teams are largely self-funded.[36]
An all transgendered netball team from Indonesia competed at the 1994 Gay Games in New York City.[41] The team had been the Indonesian national champions.[41] At the 2000 Gay Games VI in Sydney, netball and volleyball were the two sports with the highest rates of transgendered athletes participating.[42] There were eight teams of indigenous players, with seven identifying as transgendered.[42] They came from places like Palm Island in northern Queensland, Samoa, Tonga and Papua New Guinea.[42] Teams with transgendered players were allowed to participate in several divisions including men’s, mixed and transgendered; they were not allowed to compete against the cisgendered women’s teams.[42]
[edit] Description and rules
A netball court’s dimensions. The court is divided into thirds and shooting circles are at each end.
The objective of a game is to score more goals than the opposition. Goals are scored when a team member positioned in the attacking shooting circle shoots the ball through the goal ring. The goal rings are 380 millimetres (15 in) in diameter and sit atop 3.05-metre (10.0 ft)-high goal posts that have no backboards.[43] A 4.9-metre (16 ft)-radius semi-circular “shooting circle” is an area at each end of the court. The goal posts are located within the shooting circle. Each team defends one shooting circle and attacks the other.[43] The netball court is 30.5 metres (100 ft) long, 15.25 metres (50.0 ft) wide, and divided lengthwise into thirds. The ball is usually made of leather or rubber, measures 680 to 710 millimetres (27 to 28 in) in circumference, and weighs 397 to 454 grams (14.0 to 16.0 oz).[44][45] A normal game consists of four 15-minute quarters[44][46] and can be played outdoors or in a covered stadium.
Each team is allowed seven players on the court.[47] Each player is assigned a specific position, which limits her movement to a certain area on the court. A “bib” worn by each player indicates her position.[48] Only two positions are permitted in the attacking shooting circle, and can therefore shoot for a goal. Similarly, only two positions are permitted in the defensive shooting circle; they try to prevent the opposition from shooting goals. Other players are restricted to two thirds of the court, with the exception of the Centre, who may move anywhere on the court except for a shooting circle.[49]
Australia v England 12 October 2011 test match held in Canberra
At the beginning of every quarter and after a goal has been scored, play starts with a player in the Centre position passing the ball from the centre of the court. These “centre passes” alternate between the teams, regardless of which team scored the last goal. When the umpire blows the whistle to restart play, four players from each team can move into the centre third to receive the pass. The centre pass must be caught or touched in the centre third.[50][51] The ball is then moved up and down the court through passing and must be touched by a player in each adjacent third of the court. Players can hold the ball for only three seconds at any time. It must be released before the foot they were standing on when they caught it touches the ground again.[44] Contact between players is only permitted if it does not impede an opponent or the general play. When defending a pass or shot players must be at least 90 centimetres (35 in) away from the player with the ball. If illegal contact is made, the player who contacted cannot participate in play until the player taking the penalty has passed or shot the ball.[52] If the ball is held in two hands and either dropped or a shot at goal is missed, the same player cannot be the first to touch it unless it first rebounds off the goal.[53]
[edit] Variants
[edit] Indoor netball
Indoor netball is a variation of netball, played exclusively indoors, in which the playing court is surrounded on each side and overhead by a net. The net prevents the ball from leaving the court, permitting faster play by reducing playing stoppages.[54]
Different forms of indoor netball exist. In a seven-per-side version called “action netball”, seven players per team play with rules similar to netball. However, a game is split into 15-minute halves with a three-minute break in between. This version is played in Australia,[55] New Zealand,[56] South Africa[57] and England.[58]
A six-per-side version of the sport is also played in New Zealand. Two Centres per team can play in the whole court except the shooting circles; the remaining attacking and defending players are each restricted to one half of the court, including the shooting circles. The attacking and Centre players may shoot from outside the shooting circle for a two-point goal.[59][60]
A five-per-side game is also common in indoor netball. Players can move throughout the court, with the exception of the shooting circles, which are restricted to certain attacking or defending players.
[edit] Fastnet
Fastnet is a variation on the rules of netball designed to make games faster and more television-friendly. The World Netball Series promotes it to raise the sport’s profile and attract more spectators and greater sponsorship.[61][62] The game is much shorter, with each quarter lasting only six minutes and only a two-minute break between quarters.[63] The coaches can give instructions from the sideline during play, and unlimited substitutions are allowed.[63] Like six-per-side indoor netball, attacking players may shoot two-point goals from outside the shooting circle.[63][64] Each team can separately nominate one “power play” quarter, in which each goal scored by that team is worth double points and the centre pass is taken by the team that conceded the goal.[63]
[edit] For children
Children playing netball in South Africa
The rules for children are similar to those for adults, except the length of each quarter can be reduced and the height of the goal may be lower.
Fun Net is a version of netball for five– to seven-year-olds developed by Netball Australia that aims to improve basic netball skills using games and activities.[65] The Fun Net program runs for 8–16 weeks. There are no winners or losers. The goal posts are 2.4 metres (7 ft 10 in) high, and a smaller ball is used.[66]
Netball Australia also runs a modified game called Netta aimed at 8– to 11-year-olds.[67] The same goals and ball are used, but players rotate positions during the game, permitting each player to play each position.[68] Netta was created to develop passing and catching skills. Its rules permit six seconds between catching and passing the ball, instead of the three seconds permitted in the adult game.[67] Most players under 11 play this version at netball clubs.[68]
A similar version called High Five Netball is promoted by the All England Netball Association.[69] It is also aimed at 9– to 11-year-old girls and consists of just five positions.[69] The players swap positions during the game.[70] When a player is not on the court, she is expected to help the game in some other way, such as being the timekeeper or scorekeeper.[69] The game is played over four quarters, with each quarter lasting six minutes.[69][70]
[edit] Governance
The recognised international governing body of netball is the International Federation of Netball Associations (IFNA), based in Manchester, England.[17] When it was founded in 1960, the organisation was called the International Federation of Netball and Women’s Basketball.[23] The IFNA is responsible for compiling world rankings for national teams, maintaining the rules for netball and organising several major international competitions. It is governed by a congress that meets every two years, a board of directors that meets three times a year, a Chief Executive Officer and a Secretariat.[23]
As of August 2011, the IFNA claimed 74 national members in five regions.[23] Each region has an IFNA Regional Federation.[71]
The IFNA is affiliated with the General Association of International Sports Federations, the International World Games Association and the Association of IOC Recognised International Sports Federations.[72] It is also a signatory to the World Anti-Doping Code.[73]
[edit] International competition
A pass takes place during a women’s netball game in Fiji.
Netball is a popular participant sport in countries of the Commonwealth of Nations.[74][75] Non-Commonwealth entities with full IFNA membership include Switzerland, Taiwan, Thailand, Argentina, Bermuda, the Cayman Islands and the United States, along with former Commonwealth members Zimbabwe, Ireland and Hong Kong.[76] According to the IFNA, over 20 million people play netball in more than 80 countries.[23][77] International tournaments are held among countries in each of the five IFNA regions, either annually or every four years. School leagues and national club competitions have been organised in England,[78] Australia,[11] New Zealand[18] and Jamaica[19] since the early 20th century. Franchise-based netball leagues did not emerge until the late 1990s. These competitions sought to increase the profile of the sport in their respective countries. Despite widespread local interest, participation was largely amateur.[79]
Netball was one of three new sports included in the 1998 Commonwealth Games and has been a fixture ever since.[80] At the 2010 Commonwealth Games, 12 teams competed.[80] Australia and New Zealand have won two golds and two silvers each, while England has three bronzes and Jamaica one bronze.[81]
The major international tournament in Africa is organised by the Confederation of Southern African Netball Associations, which invites teams from Botswana, Namibia, Zambia, Malawi, South Africa, Lesotho, Swaziland, Zimbabwe and the Seychelles to take part.[82] The tournament is hosted by a country within the region; senior and under 21 teams compete.[82] The tournament has served as a qualifier for the World Championships.[83] South Africa launched a new domestic competition in 2011 called Netball Grand Series. It features eight regional teams from South Africa and is aimed at increasing the amount of playing time for players. It runs for 17 weeks and replaces the National Netball League, which was played over only two weeks. According to Proteas captain Elsje Jordaan it was hoped that the competition would create an opportunity for players to become professional.[84]
A player from the New South Wales Swifts (red) prepares to shoot for a goal against the Melbourne Vixens.
The American Federation of Netball Associations (AFNA) hosts two tournaments each year: the Caribbean Netball Association (CNA) Under 16 Championship and the AFNA Senior Championship.[85] The CNA championship involves two divisions of teams from the Caribbean islands. In 2010 five teams competed in two rounds of round robin matches in the Championship Division, while four teams competed in the Developmental Division.[86] Jamaica, which has lost only once in the tournament,[87] decided not to play the 2011 tournament.[86] The AFNA Senior Championship includes Canada and the USA along with the Caribbean nations. The tournament serves as a qualifier for the World Championship. Jamaica, with its high ranking, does not have to qualify; this leaves two spots to the other teams in the tournament.[88]
The Asian Netball Championship is held every four years. The seventh Asian games were held in 2009 and featured Singapore, Thailand, Maldives, Taiwan, Malaysia, Sri Lanka, Hong Kong, India and Pakistan.[89] There is also an Asian Youth Netball Championship for girls under 21 years of age, the seventh of which was held in 2010.[90]
The major netball competition in Europe is the Netball Superleague, which features nine teams from England, Wales and Scotland.[91][92] The league was created in 2005.[16] Matches are broadcast on Sky Sports.[93]
Netball has been featured at the Pacific Games, a multi-sport event with participation from 22 countries from around the South Pacific.[94] The event is held every four years and has 12 required sports; the host country chooses the other four. Netball is not a required sport and has missed selection, particularly when former French or American territories host the games.[95]
The ANZ Championship is a Trans-Tasman competition that has been broadcast on television in both New Zealand and Australia since 2008.[96] It is contested among ten teams from Australia and New Zealand. It began in April 2008, succeeding Australia’s Commonwealth Bank Trophy and New Zealand’s National Bank Cup as the pre-eminent netball league in those countries.[97] The competition is held annually between April and July, consisting of 69 matches played over 17 weeks. The ANZ Championship saw netball become a semi-professional sport in both countries, with increased media coverage and player salaries.[98][99]
[edit] Major championships
There are three major international netball competitions.
The most important competition in netball is the World Netball Championships held every four years. The first was held in 1963 at the Chelsea College of Physical Education at Eastbourne, England, with 11 nations competing. Since its inception the competition has been dominated primarily by the Australian and New Zealand teams, with ten and four titles respectively. The only other team to receive a championship title is Trinidad and Tobago in 1979. That year there were no finals and the title was shared as New Zealand, Australia and Trinidad and Tobago all finished on equal points at the end of the round robin.[100]
The World Series is a competition among the top six national netball teams according to the IFNA World Rankings.[101] It is organised by the IFNA in conjunction with the national governing bodies of the six competing nations, UK Sport, and the host city’s local council.[102] The All England Netball Association covers air travel, accommodation, food and local travel expenses for all teams, while the respective netball governing bodies cover player allowances.[103] It is held over three days, with each team playing each other once during the first two days in a round-robin format. The four highest-scoring teams advance to the semi-finals; the winners face each other in the Grand Final.[104] The competition features modified fastnet rules and has been likened to Twenty20 cricket and rugby sevens.[105][106] A new format featuring shorter matches with modified rules was designed to make the game more appealing to spectators and television audiences.[105] The World Series was held for the first time in October 2009 and is scheduled to be held annually in England until at least 2011.
Netball gained Olympic recognition in 1995 after 20 years of lobbying.[11][107] Although it has never been played at the Summer Olympics, politicians and administrators have been campaigning to have it included in the near future.[108][109] Its absence from the Olympics has been seen by the netball community as a hindrance in the global growth of the game by limiting access to media attention and funding sources.[25][110][111] Some funding sources became available with recognition in 1995,[112] including the International Olympic Committee, national Olympic committees, national sport organisations, and state and federal governments.[112][113]
[edit] See also
[edit] Notes
- ^ Numbers are taken where available from the 48 member nations of the International Federation of Netball Associates.[1] (Cook Islands 1000,[2] Fiji 5,000,[3] New Zealand 135,000,[4] Papua New Guinea 10,000,[5] Samoa 2,000,[6] England 75,000,[7] Scotland 1,800,[8] Australia 330,000,[9] Hong Kong 1,200,[10]). No current numbers are available for Vanuatu, Botswana, Ghana, Kenya, Lesotha, Malawi, Namibia, South Africa, Swaziland, Tanzania, Uganda, Zimbabwe, Zambia, Gibraltar, Malta, Northern Ireland, Ireland, Wales, Switzerland, China, India, Malaysia, Republic of the Maldives, Pakistan, Sri Lanka, Thailand, Argentina, Antigua & Barbuda, Barbados, Bermuda, Canada, Cayman Islands, Grenada, Jamaica, Trinidad & Tobago, St. Lucia, St Vincent and the Grenadines and the United States.
Human body
The human body is the entire structure of a human organism, and consists of a head, neck, torso, two arms and two legs. By the time the human reaches adulthood, the body consists of close to 100 trillion cells,[1] the basic unit of life. These cells are organised biologically to eventually form the whole body.
Size, type and proportion
|
Constituents of the human body
In a normal man weighing 60 kg |
||
| Constituent | Weight [2] | Percent of atoms[2] |
|---|---|---|
| Oxygen | 38.8 kg | 25.5 % |
| Carbon | 10.9 kg | 9.5 % |
| Hydrogen | 6.0 kg | 63 % |
| Nitrogen | 1.9 kg | 1.4 % |
| Calcium | 1.2 kg | 0.3 % |
| Phosphorus | 0.6 kg | 0.2 % |
| Potassium | 0.2 kg | 0.06 % |
The average height of an adult male human (in developed countries) is about 1.7–1.8 m (5’7″ to 5’11”) tall and the adult female about 1.6–1.7 m (5’2″ to 5’7″) tall.[3] This size is firstly determined by genes and secondly by diet. Body type and body composition are influenced by postnatal factors such as diet and exercise[citation needed].
[edit] Systems
The organ systems of the body include the musculoskeletal system, cardiovascular system, digestive system, endocrine system, integumentary system, urinary system, lymphatic system, immune system, respiratory system, nervous system and reproductive system.
Anterior (frontal) view of the opened heart. White arrows indicate normal blood flow.
[edit] Cardiovascular system
The cardiovascular system comprises the heart, veins, arteries and capillaries. The primary function of the heart is to circulate the blood, and through the blood, oxygen and vital minerals are transferred to the tissues and organs that comprise the body. The left side of the main organ (left ventricle and left atrium) is responsible for pumping blood to all parts of the body, while the right side (right ventricle and right atrium) pumps only to the lungs for re-oxygenation of the blood.[4][5] The heart itself is divided into three layers called the endocardium, myocardium and epicardium, which vary in thickness and function.[6]
[edit] Digestive system
The digestive system provides the body’s means of processing food and transforming nutrients into energy. The digestive system consists of the – buccal cavity, esophagus, stomach, small intestine, large intestine ending in the rectum and anus. These parts together are called the alimentary canal (digestive tract).
[edit] Integumentary system
The integumentary system is the largest organ system in the human body, and is responsible for protecting the body from most physical and environmental factors. The largest organ in the body, is the skin. The integument also includes appendages, primarily the sweat and sebaceous glands, hair, nails and arrectores pili (tiny muscles at the root of each hair that cause goose bumps).
[edit] Lymphatic system
The main function of the lymphatic system is to extract, transport and metabolise lymph, the fluid found in between cells. The lymphatic system is very similar to the circulatory system in terms of both its structure and its most basic function (to carry a body fluid).
[edit] Musculoskeletal system
The human musculoskeletal system consists of the human skeleton, made by bones attached to other bones with joints, and skeletal muscle attached to the skeleton by tendons.
[edit] Bones
An adult human has approximately 206 distinct bones:
- Spine and vertebral column (26)
- Cranium (8)
- Face (14)
- Hyoid bone, sternum and ribs (26)
- Upper extremities (70)
- Lower extremities (62)
[edit] Nervous system
The nervous system consists of cells that communicate information about an organism’s surroundings and itself.
[edit] Reproductive system
Human reproduction takes place as internal fertilization by sexual intercourse. During this process, the erect penis of the male is inserted into the female‘s vagina until the male ejaculates semen, which contains sperm, into the female’s vagina. The sperm then travels through the vagina and cervix into the uterus or fallopian tubes for fertilization of the ovum.
The human male reproductive system is a series of organs located outside the body and around the pelvic region of a male that contribute towards the reproductive process. The primary direct function of the male reproductive system is to provide the male gamete or spermatozoa for fertilization of the ovum.
The major reproductive organs of the male can be grouped into three categories. The first category is sperm production and storage. Production takes place in the testes which are housed in the temperature regulating scrotum, immature sperm then travel to the epididymis for development and storage. The second category are the ejaculatory fluid producing glands which include the seminal vesicles, prostate, and the vas deferens. The final category are those used for copulation, and deposition of the spermatozoa (sperm) within the female, these include the penis, urethra, vas deferens and Cowper’s gland.
The human female reproductive system is a series of organs primarily located inside of the body and around the pelvic region of a female that contribute towards the reproductive process. The human female reproductive system contains three main parts: the vagina, which acts as the receptacle for the male’s sperm, the uterus, which holds the developing fetus, and the ovaries, which produce the female’s ova. The breasts are also an important reproductive organ during the parenting stage of reproduction.
The vagina meets the outside at the vulva, which also includes the labia, clitoris and urethra; during intercourse this area is lubricated by mucus secreted by the Bartholin’s glands. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the fallopian tubes. At certain intervals, typically approximately every 28 days, the ovaries release an ovum, which passes through the fallopian tube into the uterus. The lining of the uterus, called the endometrium, and unfertilized ova are shed each cycle through a process known as menstruation.
Mornin
The word morning originally referred to the sunrise. Morning precedes midday, afternoon, and night in the sequence of a day.
Morning is the part of the day usually reckoned from dawn to noon. The name (which comes from the Middle English word morwening) was formed from the analogy of evening using the word “morn” (in Middle English morwen), and originally meant the coming of the sunrise as evening meant the beginning of the close of the day. The Middle English morwen dropped over time and became morwe, then eventually morrow, which properly means “morning”, but was soon used to refer to the following day (i.e., “tomorrow”), as in other Germanic languages—English is unique in restricting the word to the newer usage. The Spanish word “mañana” has two meanings in English: “morning,” and “tomorrow.”
Another definition of morning is the first half of the day – the period between midnight and 11:59am. The most obvious manifestation of this meaning is in English speaking countries where the greeting changes from “good night” to “good morning” when midnight passes.
Morning may also be used in a strictly personal sense, to refer to the period immediately following waking up, irrespective of the current time of day. In this sense, morning encompasses the (mostly menial) prerequisites for full productivity and life in public (i.e. cleaning, a morning meal—often breakfast, dressing, etc). The boundaries of such morning periods are by necessity idiosyncratic, but they are typically considered to have ended on reaching a state of full readiness for the day’s productive activity. This modern permutation of morning is due largely to the worldwide spread of electricity, and the concomitant independence from natural light sources.[1]
A morning newspaper is one on sale in the mornings (as opposed to an evening newspaper, on sale from about noon onwards). In practice (though this may vary according to country) this means that a morning newspaper is available in early editions from before midnight on the night before its cover date, further editions being printed and distributed during the night. Previews of tomorrow’s newspapers are often a feature of late night news programmes, such as Newsnight in the United Kingdom.
Morning meals include breakfast, though logically this need not be in the morning, and are varied across cultures. Brunch is a late morning meal.
The ability of a person to wake up effectively in the morning may be influenced by a gene called “Period 3”. This gene comes in two forms, a “short” and a “long” variant. It seems to affect the person’s preference for mornings or evenings. People who carry the long variant were over-represented as morning people, while the ones carrying the short variant were evening preference people.[1]
The word morning originally referred to the sunrise. Morning precedes midday, afternoon, and night in the sequence of a day.
Morning is the part of the day usually reckoned from dawn to noon. The name (which comes from the Middle English word morwening) was formed from the analogy of evening using the word “morn” (in Middle English morwen), and originally meant the coming of the sunrise as evening meant the beginning of the close of the day. The Middle English morwen dropped over time and became morwe, then eventually morrow, which properly means “morning”, but was soon used to refer to the following day (i.e., “tomorrow”), as in other Germanic languages—English is unique in restricting the word to the newer usage. The Spanish word “mañana” has two meanings in English: “morning,” and “tomorrow.”
Another definition of morning is the first half of the day – the period between midnight and 11:59am. The most obvious manifestation of this meaning is in English speaking countries where the greeting changes from “good night” to “good morning” when midnight passes.
Morning may also be used in a strictly personal sense, to refer to the period immediately following waking up, irrespective of the current time of day. In this sense, morning encompasses the (mostly menial) prerequisites for full productivity and life in public (i.e. cleaning, a morning meal—often breakfast, dressing, etc). The boundaries of such morning periods are by necessity idiosyncratic, but they are typically considered to have ended on reaching a state of full readiness for the day’s productive activity. This modern permutation of morning is due largely to the worldwide spread of electricity, and the concomitant independence from natural light sources.[1]
A morning newspaper is one on sale in the mornings (as opposed to an evening newspaper, on sale from about noon onwards). In practice (though this may vary according to country) this means that a morning newspaper is available in early editions from before midnight on the night before its cover date, further editions being printed and distributed during the night. Previews of tomorrow’s newspapers are often a feature of late night news programmes, such as Newsnight in the United Kingdom.
Morning meals include breakfast, though logically this need not be in the morning, and are varied across cultures. Brunch is a late morning meal.
The ability of a person to wake up effectively in the morning may be influenced by a gene called “Period 3”. This gene comes in two forms, a “short” and a “long” variant. It seems to affect the person’s preference for mornings or evenings. People who carry the long variant were over-represented as morning people, while the ones carrying the short variant were evening preference people.[1]
The word morning originally referred to the sunrise. Morning precedes midday, afternoon, and night in the sequence of a day.
Morning is the part of the day usually reckoned from dawn to noon. The name (which comes from the Middle English word morwening) was formed from the analogy of evening using the word “morn” (in Middle English morwen), and originally meant the coming of the sunrise as evening meant the beginning of the close of the day. The Middle English morwen dropped over time and became morwe, then eventually morrow, which properly means “morning”, but was soon used to refer to the following day (i.e., “tomorrow”), as in other Germanic languages—English is unique in restricting the word to the newer usage. The Spanish word “mañana” has two meanings in English: “morning,” and “tomorrow.”
Another definition of morning is the first half of the day – the period between midnight and 11:59am. The most obvious manifestation of this meaning is in English speaking countries where the greeting changes from “good night” to “good morning” when midnight passes.
Morning may also be used in a strictly personal sense, to refer to the period immediately following waking up, irrespective of the current time of day. In this sense, morning encompasses the (mostly menial) prerequisites for full productivity and life in public (i.e. cleaning, a morning meal—often breakfast, dressing, etc). The boundaries of such morning periods are by necessity idiosyncratic, but they are typically considered to have ended on reaching a state of full readiness for the day’s productive activity. This modern permutation of morning is due largely to the worldwide spread of electricity, and the concomitant independence from natural light sources.[1]
A morning newspaper is one on sale in the mornings (as opposed to an evening newspaper, on sale from about noon onwards). In practice (though this may vary according to country) this means that a morning newspaper is available in early editions from before midnight on the night before its cover date, further editions being printed and distributed during the night. Previews of tomorrow’s newspapers are often a feature of late night news programmes, such as Newsnight in the United Kingdom.
Morning meals include breakfast, though logically this need not be in the morning, and are varied across cultures. Brunch is a late morning meal.
The ability of a person to wake up effectively in the morning may be influenced by a gene called “Period 3”. This gene comes in two forms, a “short” and a “long” variant. It seems to affect the person’s preference for mornings or evenings. People who carry the long variant were over-represented as morning people, while the ones carrying the short variant were evening preference people.[1]
Giraffe
The giraffe (Giraffa camelopardalis) is an African even-toed ungulate mammal, the tallest of all extant land-living animal species, and the largest ruminant. Its scientific name, which is similar to its archaic English name of camelopard, refers to its irregular patches of color on a light background, which bear a token resemblance to a leopard‘s spots, and its face, which is similar to that of a camel. The average mass for an adult male giraffe is 1,200 kilograms (2,600 lb) while the average mass for an adult female is 830 kilograms (1,800 lb).[3][4] It is approximately 4.3 metres (14 ft) to 5.2 metres (17 ft) tall, although the tallest male recorded stood almost 6 metres (20 ft).[3][4]
The giraffe is related to other even-toed ungulates, such as deer and cattle, but is placed in a separate family, the Giraffidae, consisting of only the giraffe and its closest relative, the okapi, and their extinct relatives. Its range extends from Chad in Central Africa to South Africa. Giraffes usually inhabit savannas, grasslands, or open woodlands. However, when food is scarce they will venture into areas with denser vegetation. They prefer areas with plenty of acacia growth. They will drink large quantities of water when available, which enables them to live for extended periods in arid areas.
Etymology
The name giraffe has its earliest known origins in the Arabic word الزرافة al-zirāfah, perhaps from an African name. It appears in English from the 16th century on, often in the Italianate form giraffa. The species name camelopardalis (camelopard) is derived from its early Roman name, where it was described as having characteristics of both a camel and a leopard.[5] The English word camelopard first appeared in the 14th century and survived in common usage well into the 19th century. The Afrikaans language retained it.
Taxonomy and evolution
Comparison of the African Miocene giraffids: Palaeotragus (two top) and Climacoceras (two bottom)
The giraffe is one of only two living species of the family Giraffidae, along with the okapi. The family was once much more extensive, with over 10 fossil genera described. An early ancestor of the giraffids was a 3 m (9.8 ft) tall antelope-like mammal that roamed Europe and Asia some 30–50 million years ago (mya).[6] Closer ancestors of modern giraffes likely evolved 8 mya in southern central European, arising via the family Palaeomerycidae. Animals of the family Antilocapridae (survived by the pronghorn) and the giraffids arose from the palaeomerycids.[7] The earliest known giraffid was Climacoceras, which still resembled deer, having large antler-like ossicones. It first appeared in the early Miocene epoch. Later examples include the genera Palaeotragus (from which the okapi arose) and Samotherium, which appeared in the early-to-mid-Miocene. They were both tall at the shoulder, and had developed the simple, unbranched ossicones of modern giraffids, but still had relatively short necks.[8] From the late Pliocene onwards, the variety of giraffids drastically declined. The genus Bohlinia entered China and northern India due to climate change. From here, the genus Giraffa arose and included a number of long-necked species. Around 7 mya, Giraffa giraffes entered Africa via Ethiopia.[7] Further climate changes caused the extinction of the Asian giraffes while the African giraffes survived and radiated into several different species,[7] such as Giraffa jumae, which do not survive today.[8] G. camelopardalis arose around 1 mya in East Africa.[7]
The giraffe was one of the many species first described by Linnaeus in 1758. He gave it the binomial name of Cervus camelopardalis in the 10th edition of his Systema Naturae.[9] Brisson erected the genus Giraffa in 1762.[citation needed]
Subspecies
Genetic subdivision in the giraffe based on mitochondrial DNA sequences[10]
Different authorities recognize different numbers of subspecies, differentiated by size, colour and pattern variations and range.[1][2][11] Some of these subspecies may prove to be separate species[2] as they appear to be reproductively isolated despite their mobility.[12] The subspecies recognized by most recent authorities are:
- G. c. camelopardalis,[13] the nominate subspecies, is known as the Nubian Giraffe. Its coat pattern has large, four-sided spots of chestnut brown on an off-white background and no spots on inner sides of the legs or below the hocks. It is found in eastern Sudan and northeastern DR Congo. It has been estimated that fewer than 250 remain in the wild, but little is known about this subspecies and consequently this estimate is labelled with great uncertainty.[14] It is very rare in captivity, although kept at Al Ain Zoo in the United Arab Emirates.[15]
- G. c. reticulata,[13] known as the Reticulated[13] or Somali Giraffe, has a coat pattern of well defined patches that are usually bright orange-brown in colour.[16] These patches have sharp edges and are separated by bold, bright white lines.[16] It ranges from northeastern Kenya, into southern Ethiopia and Somalia. It has been estimated that fewer than 5.000 remain in the wild,[14] and based on ISIS records it is among the most common in zoos, with more than 450 kept.[17]
- G. c. angolensis, the Angolan or Smoky Giraffe, has large spots with some notches around the edges, extending down the entire lower leg. It is found in southern Angola, northern Namibia, southwestern Zambia, Botswana and western Zimbabwe. It has been estimated that fewer than 20,000 remain in the wild,[14] and based on ISIS records approximately 20 are kept in zoos.[17]
- G. c. antiquorum,[13] the Kordofan Giraffe, has smaller, more irregular spots that cover the inner legs. Its distribution includes southern Chad, Central African Republic and northern Cameroon. Populations in Cameroon were formerly included in G. c. peralta instead, but this was incorrect.[18] Fewer than 3,000 are believed to remain in the wild.[14] Considerable confusion has existed over the status of this subspecies and G. c. peralta in zoos. In 2007 it was shown that all “G. c. peralta” in European zoos actually are G. c. antiquorum.[18] Consequently, approximately 65 are kept in zoos based on ISIS records.[17]
- G. c. tippelskirchi,[13] known as the Maasai Giraffe[13] or Kilimanjaro Giraffe, has jagged-edged, vine-leaf shaped spots of dark brown on a brownish-cream background.[16] It is the darkest coloured subspecies.[16] It occurs in central and southern Kenya and Tanzania. It is estimated that fewer than 40,000 remain in the wild,[14] and based on ISIS records approximately 100 are kept in zoos.[17]
- G. c. rothschildi,[13] is known variously as the Rothschild Giraffe[13] or Baringo Giraffe or Ugandan Giraffe. Its coats bears deep brown, blotched or rectangular spots with poorly defined cream lines. Its legs are mostly white with no pattern.[16] Its range includes Uganda and west-central Kenya, especially near Lake Baringo. It may also occur in southern Sudan.[19] Fewer than 700 are believed to remain in the wild,[14] and based on ISIS records more than 450 are kept in zoos.[17]
- G. c. giraffa, the South African Giraffe, has rounded or blotched spots, some with star-like extensions on a light tan background, running down to the hooves. It is found in northern South Africa, southern Botswana, southern Zimbabwe and southwestern Mozambique. It is estimated that fewer than 12,000 remain in the wild,[14] and based on ISIS records approximately 45 are kept in zoos.[17]
- G. c. thornicrofti,[13] called the Thornicroft Giraffe[13] or Rhodesian Giraffe, has star-shaped or leafy spots extend to the lower leg. It is restricted to the Luangwa Valley in eastern Zambia. Fewer than 1,500 remain in the wild,[14] and based on ISIS records none are kept in zoos.[17]
- G. c. peralta,[13] commonly known as the West African Giraffe[13] or Nigerian Giraffe, has numerous pale, yellowish red spots. It is endemic to southern Niger. With fewer than 220 individuals remaining in the wild, it is the rarest giraffe subspecies.[14] Giraffes in Cameroon were formerly believed to be this subspecies, but are actually G. c. antiquorum.[18] This has also resulted in some confusion over its status in zoos, but in 2007 it was established that all “G. c. peralta” kept in European zoos actually are G. c. antiquorum.[18]
Formerly, the Kordofan and West African Giraffes were regarded as a single subspecies, but genetic evidence has confirmed that they represent two separate subspecies.[18] Comparably, the Rothschild’s Giraffe has been considered a hybrid population,[11] but genetic evidence has confirmed that it is a valid subspecies.[20] By contrast, scientists have proposed four other subspecies — Cape Giraffe (G. c. capensis), Lado Giraffe (G. c. cottoni), Congo Giraffe (G. c. congoensis), and Transvaal Giraffe (G. c. wardi) — but today none of these is widely accepted.[1] One genetic study on Smoky Giraffes suggests that the northern Namib Desert and Etosha National Park populations are distinct subspecies.[21]
Although giraffes of these populations interbreed freely under conditions of captivity, suggesting that they are subspecific populations, genetic testing published in 2007 has been interpreted to show that there may be at least six species of giraffe that are reproductively isolated and not interbreeding, even though no natural obstacles, like mountain ranges or impassable rivers block their mutual access. The study found that the two giraffe populations that live closest to each other— the reticulated giraffe (G. camelopardalis reticulata) of north Kenya, and the Masai giraffe (G. c. tippelskirchi) in south Kenya— separated genetically between 0.13 and 1.62 million years ago, judging from genetic drift in nuclear and mitochondrial DNA.[20]
The implications for conservation of as many as eleven such cryptic species and subspecies were summarised by David Brown for BBC News: “Lumping all giraffes into one species obscures the reality that some kinds of giraffe are on the brink. Some of these populations number only a few hundred individuals and need immediate protection.”[22]
Anatomy and morphology
Giraffe skeleton on display by The Museum of Osteology, Oklahoma City, Oklahoma.
Male giraffes are up to 5.5 metres (18 ft) tall at the horn tips, and weigh between 800 and 1,930 kilograms (1,800 and 4,300 lb). Females are between 4 and 4.5 metres (13 and 14.8 ft) tall and weigh between 550 and 1,180 kilograms (1,200 and 2,600 lb). The coat is made up of brown blotches or patches separated by lighter hair. Each giraffe has a unique coat pattern.[23] Besides camouflage, the patches may serve as thermal windows, being the site of large blood vessels and large sweat glands.[24] The giraffe’s fur may serve as a chemical defence, and is full of antibiotics and parasite repellents that give the animal a characteristic scent. Old males are sometimes nicknamed “stink bulls”. There are at least eleven main aromatic chemicals in the fur, although indole and 3-methylindole are responsible for most of their smell. Because the males have a stronger odour than the females, it is also suspected that it has a sexual function.[25]
Horns
Both sexes have prominent horns, formed from ossified cartilage, and known as ossicones. The appearance of horns is a reliable method of identifying the sex of giraffes, with the females displaying tufts of hair on the top of the horns, whereas males’ horns are larger and tend to be bald on top — the hairs worn away due to necking in combat. Males sometimes develop calcium deposits which form bumps on their skull as they age, which can give the appearance of up to three additional horns.[26] The horns are well vascularized as may also have a thermoregulatory function.[24]
Legs and locomotion
Giraffes also have slightly elongated forelegs, about 10% longer than their hind legs, and can reach a sprint speed of up to 60 km/h (37 mph).[27] It cannot sustain a lengthy chase. The apparent inflexibility of its legs give it a stiff gait when walking.[28] When running the giraffe thrusts its front legs into the air and when they touch the ground they push off again.[29] When the hind legs land together the process begins again.[29] The giraffe is briefly airborne when running.[29] When hunting adult giraffes, lions try to knock the lanky animal off its feet and pull it down.[30] Giraffes are difficult and dangerous prey. The giraffe defends itself with a powerful kick. A single well-placed kick from an adult giraffe can kill a predator.[28] Lions are the only predators which pose a serious threat to an adult giraffe.[31] Most attacks on giraffes occur at watering holes, when the bent-over animals are at their most vulnerable and least attentive.
Giraffes usually sleep standing up but do lie down occasionally.[citation needed]
Swimming
Although no definitive study has been publicly conducted, giraffes are assumed to be unable to swim. It has been estimated that the giraffe’s proportionally larger limbs have very high rotational inertias and this would make rapid swimming motions strenuous.[32] A swimming giraffe would be forced into a posture where the neck is sub-horizontal and since it has thorax that is pulled downwards by the large fore limbs it would not be able to move the neck and limbs synchronously as a giraffe would be able to do when moving on land. This may further hamper the animal’s ability to move its limbs effectively underwater.[32]
A computer simulation conducted by Scientific American suggested that while a giraffe could float, “they would be clumsy and unstable in water”.[33] The simulation suggests the giraffe’s high density in its limb bones would make it slow and suffer from high drag.ibid. Furthermore, the weight of the forelimbs and shoulder would pull the front of the giraffe down, straining its neck.ibid.
Neck
An adult male giraffe feeding high up on an acacia.
The giraffe’s extreme altitude is a consequence of its extremely elongated neck, which can be over 2 m (7 ft) in length,[34] accounting for nearly half of the giraffe’s vertical height. The increase in neck length results from the disproportionate elongation of the cervical vertebrae, rather than the addition of more vertebrae. The cervical vertebrae comprise about 45–50% of the giraffe vertebral column, compared to the 30% typical of similar large ungulates, including the giraffe’s closest extant relative, the okapi. This elongation, which occurs in large part after birth,[35] is a 150% increase in vertebrae length over similar sized animals – in fact, the non-cervical sections of the giraffe vertebral column exhibit identical proportions to those in okapi.[citation needed]
In addition to their elongated cervical vertebrae, in giraffes the point of articulation between the cervical and thoracic vertebrae is shifted to lie between T1 and T2, the first and second thoracic vertebrae, rather than between C7 and T1, as in most other ruminants.[34][35] This allows C7 to contribute directly to increased neck length, and has sparked the suggestion that T1 is actually C8, and giraffes have added an extra cervical vertebra.[36] However, this proposition is generally not accepted, as T1 has other morphological features, such as an articulating rib, deemed diagnostic of thoracic vertebrae. Also, the exceptions to the mammalian constraint of seven cervical vertebrae are generally characterized by increased neurological anomalies and maladies, symptoms that have not been observed in giraffes.[34]
There are two main hypotheses regarding the evolutionary origin and maintenance of elongation in giraffe necks.[37] The “competing browsers hypothesis” was originally suggested by Charles Darwin and only challenged recently. It suggests that competitive pressure from smaller browsers, such as kudu, steenbok, and impala, drove the elongation of the neck so giraffes could reach nutrients competitors could not. This advantage is real – giraffes can and do feed up to 5 m, while most of their competitors, kudu, can only feed up to about 2 m (7 ft).[38] There is also research suggesting that browsing competition below 2 m is intense, and giraffes feed more efficiently (gaining more leaf biomass per bite) higher in the canopy.[39][40] However, scientists disagree about just how much time giraffes spend feeding at levels unreachable to other browsers.[37][38][41] Although giraffes can feed as low as 0.5 m and as high as 6 m off the ground, it appears that they most often feed between 2 and 4 m (7–14 ft).[41] However, elephants also routinely feed at heights up to 5 m (they knock down only a minority of the trees they feed on), and are likely competitors at these heights. Competition for food with other giraffes could also favor the evolution of tall necks.[citation needed]
The other main theory, the sexual selection hypothesis, proposes that the long necks evolved as a secondary sexual characteristic, giving males an advantage in “necking” contests (see below) to establish dominance and obtain access to sexually receptive females.[42] In support of this theory, males have proportionally larger necks than females,[37][42] and males with longer, bigger necks are more successful in dominance displays and courtship behavior.[43] However, a major criticism of this theory is that it fails to adequately explain why female giraffes also have long necks.[44]
Bending down to drink is more strenuous for a giraffe than for other ungulates.
Circulatory system
Modifications to the giraffe’s structure have evolved, particularly to the circulatory system. A giraffe’s heart, which can weigh up to 10 kg (22 lb)[28] and measure about 60 cm (2 ft) long, must generate approximately double the normal blood pressure for an average large mammal to maintain blood flow to the brain.[28] In the upper neck, a complex pressure-regulation system called the rete mirabile prevents excess blood flow to the brain when the giraffe lowers its head to drink.[28]
The jugular veins also contain several (most commonly seven) valves to minimise blood flowing back into the head and assist it getting to the inferior vena cava and right atrium in the same situation.[45] Conversely, the blood vessels in the lower legs are under great pressure (because of the weight of fluid pressing down on them). In other animals such pressure would force the blood out through the capillary walls; giraffes, however, have a very tight sheath of thick skin over their lower limbs which maintains high extravascular pressure in the same way as a pilot’s g-suit.[13]
Lifestyle
Social structure and breeding habits
Giraffes normally gather around a food source.
Male giraffe mounting a female. Only dominant males will be able to mate.
While giraffes are usually found in groups, the composition of these groups is more fluid than in other social ungulates.[46] They are a largely transient species with few strong social bonds and aggregations usually disband every few hours, although calving groups can last weeks to months.[47] For research purposes, a “group” has been defined as “a collection of individuals that are less than a kilometre apart and moving in the same general direction.”[48] Giraffe groups can range from over 40 individuals to only a few individuals with the latter being more common.[49] Female giraffes associate in groups of a dozen or so members, occasionally including a few younger males. Calves and sub-adults are rarely alone.[48][50] Giraffe groups with young tend to feed in more open areas, presumably to provide better visibility to detect predators. This may reduce their feeding efficiency.[41]
Reproduction is broadly polygamous, with a few older males impregnating the fertile females. Male giraffes determine female fertility by tasting the female’s urine in order to detect estrus, in a multi-step process known as the Flehmen response.[47][48] Once a estrous female is detected, the male will them attempt to court her.[48][50] Males prefer younger females, possibly because the latter are more fertile,[47][48][50] while females prefer older, more dominant males.[47][48][50] During courtship, dominant males will displace subordinates from the presence of the females, by staring and walking towards them. Thus the female prolongs the courtship process for as long as possible so only the most dominant male remains and copulation will follow.
Although generally quiet and non-vocal, giraffes have been heard to communicate with various sounds. Courting males will emit loud coughs.[31] Females will call their young by whistling or bellowing. Calves will bleat, moo, or make mewing sounds. In addition, giraffes will grunt, snort, hiss, or make strange flute-like sounds. Recent research has provided evidence that the giraffes produce infrasound.[51]
Two young, Maasai Giraffes, Serengeti National Parkm Tanzania. About 1 week old. One in background still has umbilical cord.
Birthing, parental care, and lifespan
Giraffe gestation lasts between 400 and 460 days, after which a single calf is normally born, although twins occasionally occur.[52] The mother gives birth standing up and the embryonic sack usually bursts when the baby falls to the ground. Newborn giraffes are about 1.8 m (5 ft. 11 in.) tall.
Within a few hours of being born, calves can run around and are indistinguishable from a week-old calf; however, for the first two weeks, they spend most of their time lying down, guarded by the mother.[47][53] It has been speculated that their characteristic spotted pattern provides a certain degree of camouflage. Mothers with calves will gather in nursery herds which are usually made up of two or more infants and/or juveniles and their mothers moving or browsing together.[53] Mothers in a groups may sometimes leave their calves with one female while they travelled to other areas. It is what’s known as a “calving pool”.[53] Males largely play no role in raising the young.
The young can fall prey to lions, Nile crocodiles, leopards, spotted hyenas, and wild dogs. Mother giraffes will defend their young by placing themselves between the young and the predator and kicking the predator.[50] Giraffes only defend their own young and form calving herds for selfish reasons.[53] Only 25 to 50% of giraffe calves reach adulthood. Maximum lifespan is ~25 years in the wild[13] and 28 years in captivity.[54]
Sleep
The giraffe has one of the shortest sleep requirements of any mammal, which averages only 4.5 or 4.6 hours per day.[55][56][57]
Necking
Male giraffes will engage in necking for various reasons, notably combat and homosexual courtship.
Male giraffes often engage in necking, which has been described as having various functions. One of these is combat. Battles can be fatal, but are more often less severe, generally ending when one giraffe surrenders to the other. The longer the neck, and the heavier the head at the end of the neck, the greater the force a giraffe is able to deliver in a blow. It has also been observed that males that are successful in necking have greater access to estrous females, so the length of the neck may be a product of sexual selection.[58]
After a necking duel, a giraffe can land a powerful blow with his head — occasionally knocking a male opponent to the ground. These fights rarely last more than a few minutes or end in physical harm.
Another function of necking is homosexual, in which two males caress and court each other, leading up to mounting and climax. Such interactions between males are more frequent than heterosexual coupling.[59] In one study, up to 94% of observed mounting incidents took place between two males. The proportion of same sex activities varied between 30 and 75%, and at any given time one in twenty males were engaged in non-combative necking behaviour with another male. Only 1% of same-sex mounting incidents occurred between females.[60]
Diet
Giraffe extending its tongue to feed. Its tongue, lips and palate are tough enough to deal with sharp thorns in trees.
Giraffes browse on the twigs of trees, preferring trees of the genera Acacia, Commiphora and Terminalia, and also eat grass and fruit.[11][61] The tongue, lips and palate are tough, which allows them to feed on trees with sharp thorns. The giraffe’s tongue is about 45 centimetres (18 in)) long and prehensile, allowing the animal to grasp leaves with it. In Southern Africa, giraffes feed on all acacias, especially Acacia erioloba. A giraffe can eat 65 pounds (29 kg) of leaves and twigs daily, but can survive on just 15 pounds (6.8 kg).[61]
The giraffe requires less food than typical grazing animals, because the foliage it eats has more concentrated nutrition and it has a more efficient digestive system.[11] During the wet season, food is abundant and giraffes disperse widely, but during the dry season they need to congregate around evergreen trees and bushes.[11] As a ruminant, it first chews its food, then swallows for processing and then visibly regurgitates the semi-digested cud up their necks and back into the mouth, to chew again. This process is usually repeated several times for each mouthful. The giraffe can survive without water for extended periods.[61] Compared with domestic cattle, giraffes have a comparatively short small intestine and a comparatively long large intestine, giving it a small ratio of small:large intestine.[62]
Stereotypic behavior
Many animals when kept in captivity, such as in zoos, display abnormal behaviours. Such unnatural behaviours are known as stereotypic behaviours.[63] In particular, giraffes show distinct patterns of stereotypic behaviours when removed from their natural environment. Due to a subconscious response to suckle milk from their mother, something which many human-reared giraffes and other captive animals do not experience, giraffes resort instead to excessive tongue use on inanimate objects.[64]
Human interactions
Painting of a giraffe taken from Somalia to China during the Ming Dynasty
In art and culture
Ancient Egyptian art depicting Nubians with a giraffe (c. 1358-1350 BCE)
Arab prophets and poets considered the giraffe the “queen of beasts” for what they saw as its delicate features and fragile form.[65] Eastern sultans prized them as special pets.[65] Giraffes were also known to the people of the Mediterranean region during antiquity.[65] Ten of these animals were apparently kept by Pompey at his theater in Rome.[65] During the Middle Ages, giraffes apparently were mostly forgotten by Europeans except in legends from Arab travelers.[65] The Medici giraffe was a giraffe presented to Lorenzo de’ Medici in 1486. It caused a great stir on its arrival in Florence,[66] being reputedly the first living giraffe to be seen in Italy since the days of Ancient Rome. Another famous giraffe, called Zarafa, was brought from Africa to Paris in the early 19th century and kept in a menagerie for 18 years.[67] Giraffe is a novel by the author J. M. Ledgard. The work concerns a true incident in which 49 giraffes were slaughtered in the Czech Republic (then Czechoslovakia) in 1975 following the suspected outbreak of disease amongst the group. The novel contains extensive information about the species, including the long history of European fascination with the beast and its captivity in zoos.
Giraffes can be seen in paintings, including the famous painting of a giraffe which was taken from Somalia to China in 1414. The giraffe was placed in a Ming Dynasty zoo.[68] At one point the giraffe was associated with the mythical Qilin, and a derivative of that name (kirin) is still used as the word for giraffe in Japan, Taiwan, and Korea.
Giraffes continue to have a presence in modern popular culture; most notably Toys “R” Us mascot Geoffrey the Giraffe. They also appear as miscellaneous characters in films like The Lion King and Dumbo. They have had more prominent roles with Melman from Madagascar and Longrack from the Transformers universe.
Scientific inspiration
Giraffes have been used as examples for introducing ideas in evolution, especially to illustrate the ideas of Lamarck. Lamarck believed that the giraffe’s long neck developed as a result of ancestral giraffe’s reaching to browse on the leaves of tall trees.[69] In addition the coat patterns of several subspecies of giraffe have been modelled using reaction-diffusion mechanisms.[70] NASA has studied the giraffe’s circulatory system and used the animal’s ability to keep blood from pooling in its lower body as a model to help astronauts returning from space.[71]
Conservation
The last viable population of the West African Giraffe is between Kouré and the Dosso Reserve in Niger.
Overall, the giraffe is regarded as Least Concern from a conservation perspective by the International Union for Conservation of Nature (IUCN), as it still is widespread and occurs in numerous reserves.[2] However, the giraffe has been extirpated from many parts of its former range, including Burkina Faso, Eritrea, Guinea, Malawi, Mauritania and Senegal.[2] It may also have disappeared from Angola, Mali and Nigeria.[2] Two subspecies, the West African Giraffe (G. c. peralta) and the Rothschild Giraffe (G. c. rothschildi), have been classified as endangered[19][72] with wild populations of each of these numbering in the hundreds.[14] Additionally, it has been suggested that the Nubian Giraffe (G. c. camelopardalis) is the most threatened of all giraffes[11] and may number fewer than 250, but little recent information is available and consequently that estimate is labelled with considerable uncertainty.[14]
Giraffes are hunted for their tails, hides and meat.[61] The tails are used as good luck charms, thread and flyswatters.[61] In addition, habitat destruction also hurts the giraffe. In the Sahel trees are cut down for firewood and to make way for livestock. Normally, giraffes are able to cope with livestock since they feed in the trees above their heads. The giraffe is a protected species in most of its range. The total African giraffe population has been estimated to range from 110,000 to 150,000. Kenya (45,000), Tanzania (30,000), and Botswana (12,000), have the largest national populations.[73] More recent estimates suggest fewer than 80,000 rema
Satur
In Roman mythology, Saturn is the god of agriculture. The associated Greek god, Cronus, was the son of Uranus and Gaia and the father of Zeus (Jupiter). Saturn is the root of the English word “Saturday” (see Appendix 5).
Saturn has been known since prehistoric times. Galileo was the first to observe it with a telescope in 1610; he noted its odd appearance but was confused by it. Early observations of Saturn were complicated by the fact that the Earth passes through the plane of Saturn’s rings every few years as Saturn moves in its orbit. A low resolution image of Saturn therefore changes drastically. It was not until 1659 that Christiaan Huygens correctly inferred the geometry of the rings. Saturn’s rings remained unique in the known solar system until 1977 when very faint rings were discovered around Uranus (and shortly thereafter around Jupiter and Neptune).
Saturn was first visited by NASA’s Pioneer 11 in 1979 and later by Voyager 1 and Voyager 2. Cassini (a joint NASA / ESA project) arrived on July 1, 2004 and will orbit Saturn for at least four years.
Saturn is visibly flattened (oblate) when viewed through a small telescope; its equatorial and polar diameters vary by almost 10% (120,536 km vs. 108,728 km). This is the result of its rapid rotation and fluid state. The other gas planets are also oblate, but not so much so.
Saturn is the least dense of the planets; its specific gravity (0.7) is less than that of water.
Like Jupiter, Saturn is about 75% hydrogen and 25% helium with traces of water, methane, ammonia and “rock”, similar to the composition of the primordial Solar Nebula from which the solar system was formed.
Saturn’s interior is similar to Jupiter’s consisting of a rocky core, a liquid metallic hydrogen layer and a molecular hydrogen layer. Traces of various ices are also present.
Saturn’s interior is hot (12000 K at the core) and Saturn radiates more energy into space than it receives from the Sun. Most of the extra energy is generated by the Kelvin-Helmholtz mechanism as in Jupiter. But this may not be sufficient to explain Saturn’s luminosity; some additional mechanism may be at work, perhaps the “raining out” of helium deep in Saturn’s interior.
The bands so prominent on Jupiter are 
much fainter on Saturn. They are also much wider near the equator. Details in the cloud tops are invisible from Earth so it was not until the Voyager encounters that any detail of Saturn’s atmospheric circulation could be studied. Saturn also exhibits long-lived ovals (red spot at center of image at right) and other features common on Jupiter. In 1990, HST observed an enormous white cloud near Saturn’s equator which was not present during the Voyager encounters; in 1994 another, smaller storm was observed (left).
Two prominent rings (A and B) and one faint ring (C) can be seen from the Earth. The gap between the A and B rings is known as the Cassini division. The much fainter gap in the outer part of the A ring is known as the Encke Division (but this is somewhat of a misnomer since it was very likely never seen by Encke). The Voyager pictures show four additional faint rings. Saturn’s rings, unlike the rings of the other planets, are very bright (albedo 0.2 – 0.6).
Though they look continuous from the Earth, the rings are actually composed of innumerable small particles each in an independent orbit. They range in size from a centimeter or so to several meters. A few kilometer-sized objects are also likely.
Saturn’s rings are extraordinarily thin: though they’re 250,000 km or more in diameter they’re less than one kilometer thick. Despite their impressive appearance, there’s really very little material in the rings — if the rings were compressed into a single body it would be no more than 100 km across.
The ring particles seem to be composed primarily of water ice, but they may also include rocky particles with icy coatings.
Voyager confirmed the existence of puzzling radial inhomogeneities in the rings called “spokes” which were first reported by amateur astronomers (left). Their nature remains a mystery, but may have something to do with Saturn’s magnetic field.
Saturn’s outermost ring, the F-ring, is a complex structure made up of several smaller rings along which “knots” are visible. Scientists speculate that the knots may be clumps of ring material, or mini moons. The strange braided appearance visible in the Voyager 1 images (right) is not seen in the Voyager 2 images perhaps because Voyager 2 imaged regions where the component rings are roughly parallel. They are prominent in the Cassini images which also show some as yet unexplained wispy spiral structures.
There are complex tidal resonances between some of Saturn’s moons and the ring system: some of the moons, the so-called “shepherding satellites” (i.e. Atlas, Prometheus and Pandora) are clearly important in keeping the rings in place; Mimas seems to be responsible for the paucity of material in the Cassini division, which seems to be similar to the Kirkwood gaps in the asteroid belt; Pan is located inside the Encke Division and S/2005 S1 is in the center of the Keeler Gap. The whole system is very complex and as yet poorly understood.
The origin of the rings of Saturn (and the other jovian planets) is unknown. Though they may have had rings since their formation, the ring systems are not stable and must be regenerated by ongoing processes, perhaps the breakup of larger satellites. The current set of rings may be only a few hundred million years old.
Like the other jovian planets, Saturn has a significant magnetic field.
When it is in the nighttime sky, Saturn is easily visible to the unaided eye. Though it is not nearly as bright as Jupiter, it is easy to identify as a planet because it doesn’t “twinkle” like the stars do. The rings and the larger satellites are visible with a small astronomical telescope. There are several Web sites that show the current position of Saturn (and the other planets) in the sky. More detailed and customized charts can be created with a planetarium program.
Saturn’s Satellites
Saturn has 53 named satellites (as of spring 2010):
- The three pairs Mimas-Tethys, Enceladus-Dione and Titan-Hyperion interact gravitationally in such a way as to maintain stable relationships between their orbits: the period of Mimas’ orbit is exactly half that of Tethys, they are thus said to be in a 1:2 resonance; Enceladus-Dione are also 1:2; Titan-Hyperion are in a 3:4 resonance.
- See Scott Sheppard’s site for the latest about recently discovered moons (there are lots).
- There are 9 more that have been discovered but as yet not named.
Major moons:
Distance Radius Mass Satellite (000 km) (km) (kg) Discoverer Date --------- -------- ------ ------- ---------- ----- Pan 134 10 ? Showalter 1990 Atlas 138 14 ? Terrile 1980 Prometheus 139 46 2.70e17 Collins 1980 Pandora 142 46 2.20e17 Collins 1980 Epimetheus 151 57 5.60e17 Walker 1980 Janus 151 89 2.01e18 Dollfus 1966 Mimas 186 196 3.80e19 Herschel 1789 Enceladus 238 260 8.40e19 Herschel 1789 Tethys 295 530 7.55e20 Cassini 1684 Telesto 295 15 ? Reitsema 1980 Calypso 295 13 ? Pascu 1980 Dione 377 560 1.05e21 Cassini 1684 Helene 377 16 ? Laques 1980 Rhea 527 765 2.49e21 Cassini 1672 Titan 1222 2575 1.35e23 Huygens 1655 Hyperion 1481 143 1.77e19 Bond 1848 Iapetus 3561 730 1.88e21 Cassini 1671 Phoebe 12952 110 4.00e18 Pickering 1898
Saturn’s Rings
Radius Radius approx. approx. Name inner outer width position mass (kg) ---- ------ ------ ----- -------- -------- D-Ring 67,000 74,500 7,500 (ring) Guerin Division C-Ring 74,500 92,000 17,500 (ring) 1.1e18 Maxwell Division 87,500 88,000 500 (divide) B-Ring 92,000 117,500 25,500 (ring) 2.8e19 Cassini Division 115,800 120,600 4,800 (divide) Huygens Gap 117,680 (n/a) 285-440 (subdiv) A-Ring 122,200 136,800 14,600 (ring) 6.2e18 Encke Minima 126,430 129,940 3,500 29%-53% Encke Division 133,410 133,740 Keeler Gap 136,510 136,550 F-Ring 140,210 30-500 (ring) G-Ring 165,800 173,800 8,000 (ring) 1e7? E-Ring 180,000 480,000 300,000 (ring) Notes: * distance is kilometers from Saturn's center * the "Encke Minima" is a slang term used by amateur astronomers, not an official IAU designation
This categorization is actually somewhat misleading as the density of particles varies in a complex way not indicated by a division into neat regions: there are variations within the rings; the gaps are not entirely empty; the rings are not perfectly circular.
More about Saturn and its Satellites
- more Saturn images
- from NSSDC
- Cassini Home Page at JPL
- Saturn Events from TAMU
- Saturn’s Ring System
- the cause of the ring gaps, from Phil Plait’s excellent Bitsize Astronomy site
- Saturn Ring Plane Crossings
- Voyager Saturn Science Summary
- Saturn Ring Plane Crossing info from JPL, info and images from STScI
- Sun Crossing of Saturn’s Ring Plane from WIYN Observatory
- Historical Background of Saturn’s Rings and satellites (from JPL)
- Saturnian System Nomenclature Tables
- Saturn’s rings in natural color from Cassini
Open Issues
- How does Saturn generate its internal heat?
- What are the “spokes” in the rings?
- What is the origin of the rings? What does that tell us about the origin of the solar system as a whole? Why are Saturn’s rings so much more dramatic than the others?
- The NASA/ESACassini orbiter entered into orbit around Saturn on July 1st, 2004. In addition to an extensive survey of Saturn and its major moons, it will drop a probe (called Huygens, built by the European Space Agency) onto the surface of Titan.
Read more about Saturn l Saturn facts, pictures and information. by nineplanets.org
Jupiter
Jupiter is the fourth brightest object in the sky (after the Sun, the Moon and Venus). It has been known since prehistoric times as a bright “wandering star”. But in 1610 when Galileo first pointed a telescope at the sky he discovered Jupiter’s four large moons Io, Europa, Ganymede and Callisto (now known as the Galilean moons) and recorded their motions back and forth around Jupiter. This was the first discovery of a center of motion not apparently centered on the Earth. It was a major point in favor of Copernicus‘s heliocentric theory of the motions of the planets (along with other new evidence from his telescope: the phases of Venus and the mountains on the Moon). Galileo’s outspoken support of the Copernican theory got him in trouble with the Inquisition. Today anyone can repeat Galileo’s observations (without fear of retribution 🙂 using binoculars or an inexpensive telescope.
Jupiter was first visited by Pioneer 10 in 1973 and later by Pioneer 11, Voyager 1, Voyager 2 and Ulysses. The spacecraft Galileo orbited Jupiter for eight years. It is still regularly observed by the Hubble Space Telescope.
The gas planets do not have solid surfaces, their gaseous material simply gets denser with depth (the radii and diameters quoted for the planets are for levels corresponding to a pressure of 1 atmosphere). What we see when looking at these planets is the tops of clouds high in their atmospheres (slightly above the 1 atmosphere level).
Jupiter is about 90% hydrogen and 10% helium (by numbers of atoms, 75/25% by mass) with traces of methane, water, ammonia and “rock”. This is very close to the composition of the primordial Solar Nebula from which the entire solar system was formed. Saturn has a similar composition, but Uranus and Neptune have much less hydrogen and helium.
Our knowledge of the interior of Jupiter (and the other gas planets) is highly indirect and likely to remain so for some time. (The data from Galileo‘s atmospheric probe goes down only about 150 km below the cloud tops.)
Jupiter probably has a core of rocky material amounting to something like 10 to 15 Earth-masses.
Above the core lies the main bulk of the planet in the form of liquid metallic hydrogen. This exotic form of the most common of elements is possible only at pressures exceeding 4 million bars, as is the case in the interior of Jupiter (and Saturn). Liquid metallic hydrogen consists of ionized protons and electrons (like the interior of the Sun but at a far lower temperature). At the temperature and pressure of Jupiter’s interior hydrogen is a liquid, not a gas. It is an electrical conductor and the source of Jupiter’s magnetic field. This layer probably also contains some helium and traces of various “ices“.
The outermost layer is composed primarily of ordinary molecular hydrogen and helium which is liquid in the interior and gaseous further out. The atmosphere we see is just the very top of this deep layer. Water, carbon dioxide, methane and other simple molecules are also present in tiny amounts.
Recent experiments have shown that hydrogen does not change phase suddenly. Therefore the interiors of the jovian planets probably have indistinct boundaries between their various interior layers.
Three distinct layers of clouds are believed to exist consisting of ammonia ice, ammonium hydrosulfide and a mixture of ice and water. However, the preliminary results from the Galileo probe show only faint indications of clouds (one instrument seems to have detected the topmost layer while another may have seen the second). But the probe’s entry point (left) was unusual — Earth-based telescopic observations and more recent observations by the Galileo orbiter suggest that the probe entry site may well have been one of the warmest and least cloudy areas on Jupiter at that time.
Data from the Galileo atmospheric probe also indicate that there is much less water than expected. The expectation was that Jupiter’s atmosphere would contain about twice the amount of oxygen (combined with the abundant hydrogen to make water) as the Sun. But it now appears that the actual concentration much less than the Sun’s. Also surprising was the high temperature and density of the uppermost parts of the atmosphere.
Jupiter and the other gas planets have high velocity winds which are confined in wide bands of latitude. The winds blow in opposite directions in adjacent bands. Slight chemical and temperature differences between these bands are responsible for the colored bands that dominate the planet’s appearance. The light colored bands are called zones; the dark ones belts. The bands have been known for some time on Jupiter, but the complex vortices in the boundary regions between the bands were first seen by Voyager. The data from the Galileo probe indicate that the winds are even faster than expected (more than 400 mph) and extend down into as far as the probe was able to observe; they may extend down thousands of kilometers into the interior. Jupiter’s atmosphere was also found to be quite turbulent. This indicates that Jupiter’s winds are driven in large part by its internal heat rather than from solar input as on Earth.
The vivid colors seen in Jupiter’s clouds are probably the result of subtle chemical reactions of the trace elements in Jupiter’s atmosphere, perhaps involving sulfur whose compounds take on a wide variety of colors, but the details are unknown.
The colors correlate with the cloud’s altitude: blue lowest, followed by browns and whites, with reds highest. Sometimes we see the lower layers through holes in the upper ones.
The Great Red Spot (GRS) has been seen by Earthly observers for more than 300 years (its discovery is usually attributed to Cassini, or Robert Hooke in the 17th century). The GRS is an oval about 12,000 by 25,000 km, big enough to hold two Earths. Other smaller but similar spots have been known for decades. Infrared observations and the direction of its rotation indicate that the GRS is a high-pressure region whose cloud tops are significantly higher and colder than the surrounding regions. Similar structures have been seen on Saturn and Neptune. It is not known how such structures can persist for so long.
Jupiter radiates more energy into space than it receives from the Sun. The interior of Jupiter is hot: the core is probably about 20,000 K. The heat is generated by the Kelvin-Helmholtz mechanism, the slow gravitational compression of the planet. (Jupiter does NOT produce energy by nuclear fusion as in the Sun; it is much too small and hence its interior is too cool to ignite nuclear reactions.) This interior heat probably causes convection deep within Jupiter’s liquid layers and is probably responsible for the complex motions we see in the cloud tops. Saturn and Neptune are similar to Jupiter in this respect, but oddly, Uranus is not.
Jupiter is just about as large in diameter as a gas planet can be. If more material were to be added, it would be compressed by gravity such that the overall radius would increase only slightly. A star can be larger only because of its internal (nuclear) heat source. (But Jupiter would have to be at least 80 times more massive to become a star.)
Jupiter has a huge magnetic field, much stronger than Earth’s. Its magnetosphere extends more than 650 million km (past the orbit of Saturn!). (Note that Jupiter’s magnetosphere is far from spherical — it extends “only” a few million kilometers in the direction toward the Sun.) Jupiter’s moons therefore lie within its magnetosphere, a fact which may partially explain some of the activity on Io. Unfortunately for future space travelers and of real concern to the designers of the Voyager and Galileo spacecraft, the environment near Jupiter contains high levels of energetic particles trapped by Jupiter’s magnetic field. This “radiation” is similar to, but much more intense than, that found within Earth’s Van Allen belts. It would be immediately fatal to an unprotected human being.
The Galileo atmospheric probe discovered a new intense radiation belt between Jupiter’s ring and the uppermost atmospheric layers. This new belt is approximately 10 times as strong as Earth’s Van Allen radiation belts. Surprisingly, this new belt was also found to contain high energy helium ions of unknown origin.
Jupiter has rings like Saturn’s, but much fainter and smaller (right). They were totally unexpected and were only discovered when two of the Voyager 1 scientists insisted that after traveling 1 billion km it was at least worth a quick look to see if any rings might be present. Everyone else thought that the chance of finding anything was nil, but there they were. It was a major coup. They have since been imaged in the infra-red from ground-based observatories and by Galileo.
Unlike Saturn’s, Jupiter’s rings are dark (albedo about .05). They’re probably composed of very small grains of rocky material. Unlike Saturn’s rings, they seem to contain no ice.
Particles in Jupiter’s rings probably don’t stay there for long (due to atmospheric and magnetic drag). The Galileo spacecraft found clear evidence that the rings are continuously resupplied by dust formed by micrometeor impacts on the four inner moons, which are very energetic because of Jupiter’s large gravitational field. The inner halo ring is broadened by interactions with Jupiter’s magnetic field.
In July 1994, Comet Shoemaker-Levy 9 collided with Jupiter with spectacular results (left). The effects were clearly visible even with amateur telescopes. The debris from the collision was visible for nearly a year afterward with HST.
When it is in the nighttime sky, Jupiter is often the brightest “star” in the sky (it is second only to Venus, which is seldom visible in a dark sky). The four Galilean moons are easily visible with binoculars; a few bands and the Great Red Spot can be seen with a small astronomical telescope. There are several Web sites that show the current position of Jupiter (and the other planets) in the sky. More detailed and customized charts can be created with a planetarium program.
Jupiter’s Satellites
Jupiter has 63 known satellites (as of Feb 2004): the four large Galileanmoons plus many more small ones some of which have not yet been named:
- Jupiter is very gradually slowing down due to the tidal drag produced by the Galilean satellites. Also, the same tidal forces are changing the orbits of the moons, very slowly forcing them farther from Jupiter.
- Io, Europa and Ganymede are locked together in a 1:2:4 orbital resonanceand their orbits evolve together. Callisto is almost part of this as well. In a few hundred million years, Callisto will be locked in too, orbiting at exactly twice the period of Ganymede (eight times the period of Io).
- Jupiter’s satellites are named for other figures in the life of Zeus (mostly his numerous lovers).
- Many more small moons have been discovered recently but have not as yet been officially confirmed or named. The most up to date info on them can be found at Scott Sheppard’s site.
Distance Radius Mass Satellite (000 km) (km) (kg) Discoverer Date --------- -------- ------ ------- ---------- ----- Metis 128 20 9.56e16 Synnott 1979 Adrastea 129 10 1.91e16 Jewitt 1979 Amalthea 181 98 7.17e18 Barnard 1892 Thebe 222 50 7.77e17 Synnott 1979 Io 422 1815 8.94e22 Galileo 1610 Europa 671 1569 4.80e22 Galileo 1610 Ganymede 1070 2631 1.48e23 Galileo 1610 Callisto 1883 2400 1.08e23 Galileo 1610 Leda 11094 8 5.68e15 Kowal 1974 Himalia 11480 93 9.56e18 Perrine 1904 Lysithea 11720 18 7.77e16 Nicholson 1938 Elara 11737 38 7.77e17 Perrine 1905 Ananke 21200 15 3.82e16 Nicholson 1951 Carme 22600 20 9.56e16 Nicholson 1938 Pasiphae 23500 25 1.91e17 Melotte 1908 Sinope 23700 18 7.77e16 Nicholson 1914
Values for the smaller moons are approximate. Many more small moons are not listed here.
Jupiter’s Rings
Distance Width Mass Ring (km) (km) (kg) ---- -------- ----- ------ Halo 100000 22800 ? Main 122800 6400 1e13 Gossamer 129200 214200 ?
(distance is from Jupiter’s center to the ring’s inner edge)
More about Jupiter and its satellites
- more Jupiter images
- from NSSDC
- Voyager Jupiter Science Summary
- Galileo Education and Public Outreach (including the latest images)
- Jupiter’s Rings from JPL
- Galileo report on Jupiter’s rings (1998)
- Jupiter’s Ring System
- Jupiter Events from TAMU
- Online from Jupiter, NASA information about the Galileo mission for K-12 educators
- The Discovery of the Galilean Satellites
- Jovian System Nomenclature Tables
- Preliminary! Galileo Probe Results from JPL and ARC and LANL
- Galileo Probe Mission “Quick-look” Science Summary 1/25/96 from ARC
- Galileo science report 3/18/96
- Galileo Probe Results suggest our theories of the origin of the solar system need revision
- The Jupiter Satellite Page by Scott Sheppard
Open Issues
- Galileo‘s atmospheric probe provides our first direct measurements of Jupiter’s atmosphere, our first real data about the chemistry of a gas planet. The initial data indicate a major new mystery — why is there so little water in Jupiter’s atmosphere? There is a building consensus that the probe encountered an unusually dry area but more details are needed.
- Just how deep into the interior do the zonal winds extend? What mechanism drives them?
- Why is the GRS so persistent? There are actually several theoretical models that seem to work. We need more data to decide between them.
- How can we get more direct information about the interior? Liquid metallic hydrogen has been produced in a lab at Lawrence Livermore National Laboratory but much about its properties is still unknown.
- Why are Jupiter’s rings so dark while Saturn’s are so bright?
Read more about Jupiter l Jupiter facts, pictures and information. by nineplanets.org
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