Saturday, January 31, 2009


The Cheetah (Acinonyx jubatus) is an atypical member of the cat family ( Felidae) that hunts by speed rather than by stealth or pack tactics. It is the fastest of all terrestrial animals and can reach speeds of up to 100 km/h (62 mph) in short bursts.

Description

The cheetah's body is svelte and muscular, though it seems slender and almost fragile in build. Its chest is deep and its waist narrow. It has a small head and short muzzle, high-placed eyes, large nostrils for maximal oxygen intake, and small round ears. The fur of the cheetah is yellow with round black spots which help to camouflage it and black tear lines on the sides of the muzzle. The adult animal weighs from 40 to 65 kg (90 to 140 lb). Its total body length is from 112 to 135 cm (45 in to 55 in), while the tail can measure up to 84 cm (33 in).

A Cheetah in Serengeti National Park, Tanzania

Cheetahs also have a rare fur pattern mutation, and cheetahs with larger, blotchy, merged spots are known as 'King Cheetahs'. It was once thought to be a separate sub-species, but it is merely a mutation of the African Cheetah. A 'King Cheetah' has only been seen in the wild a handful of times, but they have been bred in captivity (see below).

Cheetahs are not true big cats, as they can purr as they inhale, but cannot roar. By contrast, lions, tigers, leopards, and jaguars can roar but cannot purr, except while exhaling. However, cheetahs are still considered by many to be the smallest of the big cats. While it is often mistaken for a leopard, the cheetah does have distinguishing features, such as the long tear-drop shaped lines on each side of its nose that run from the corner of its eyes to its mouth. The body frame of a cheetah is also very different from that of the leopard, most notably so in its thinner and extra long tail. The cheetah’s coat is tan, or buff colored, with black spots measuring from ¾ to 1 ¼ inches across. There are no spots on its white belly, and the tail has spots which merge to form four to six dark rings at the end. The cheetah's tail usually ends in a bushy white tuft. Male cheetahs are slightly larger than females and have a slightly bigger head, but it is difficult to tell males and females apart by appearance alone. The cheetah is a vulnerable species. Out of all the big cats, it is the least able to adapt to new environments. They have always proved difficult to breed in captivity, but recently a few zoos have been successful. Once widely shot for its fur, the cheetah now suffers more from the loss of both habitat and prey. The cheetah is considered the most primitive of all cats, and until recently was thought to have evolved approximately 18 million years ago, although new research puts the last common ancestor of all 37 existing species of feline more recently, at 11 million years. The cheetah has lions and hyenas as natural enemies. The cheetah's paws have only semi-retractable claws, the only of its type amongst the species of cat, and offer the cat extra grip in its high-speed pursuits. It should be noted that the ligament structure of the cheetah's claws is the same as those of other cats, it simply lacks the sheath of skin and fur present in other varieties, and therefore the claws are always visible. With the exception of the dewclaw, the claw itself is also much shorter and straighter than other cats.

Classification

The genus name, Acinonyx, means "no-move-claw" in Greek, while the species name, jubatus, means "maned" in Latin, a reference to the mane found in cheetah cubs. It is the only cat that cannot completely retract its claws. Even when retracted, the claws remain visible and are used for grip during the cheetah's acceleration and maneuvering, performing the same function as canine claws.

The English word "cheetah" comes from Hindi chiitaa, which is perhaps derived from Sanskrit chitraka, meaning "the spotted one". Other major European languages use variants of the medieval Latin gattus pardus, meaning "cat-leopard": French guépard; Italian ghepardo; Spanish and Portuguese guepardo (also used chita); and German Gepard.

Reproduction and social life

Cheetahs in Masai Mara game reserve, Kenya

Cheetah acquires sexual maturity in 20 to 24 months. Mating season is throughout the year. Females give birth to one to five kittens¹ after a gestation of ninety to ninety-five days. The kittens weigh from 150 to 300 g (5 to 10 oz.) at birth. Unlike some other cats, cheetahs are born with their characteristic spots. Cheetah kittens are also born with a downy underlying fur on their necks, extending to mid-back. This gives them a mane or mohawk type appearance, this fur is shed as the cheetahs grow older. Death-rate is very high during the early weeks and up to 90% of the kittens are killed during this time by lions, hyenas or even by eagles. They leave their mother between thirteen and twenty months after birth. The cheetah can live over twenty years, but their life is often short for they lose their speed due to old age. Unlike other felines, the adult females do not have true territories and seem to avoid each other, though some mother/daughter pairs have been known to continue for small periods of time. Males sometimes form small groups, especially when they come from the same litter. Usually these groups consist of two or three brothers. Coalitions of many male cheetahs are much more successful at winning and keeping territories than the ones who live alone. Life span is up to 12 years in wild, much longer in captivity.

¹Cheetah young are referred to as kittens because although they are considered a big cat, they are not one of the "great cats". Great cats include lions, tigers, jaguars and leopards. The great cats are distinguished from the other big cats (cheetahs, pumas, snow leopards and clouded leopards) with their ability to purr. The young of the 'great cats' are called cubs, while the young of other large cats are usually referred to as kittens.

Food

A running cheetah

Cheetahs are carnivores, eating mostly mammals under 40 kg (90 lb), including Thomson's gazelles, and impala. Wildebeest and calves are hunted when cheetahs hunt together. Guinea fowl and hares are also hunted. While the other big cats mainly hunt by night, the cheetah is a diurnal hunter. It hunts usually either early in the morning or later in the night when it is not so hot, but there is still enough light - cheetahs hunt by vision rather than by scent. Prey is stalked to within ten to thirty meters (30-100 ft), then chased. Using their tails to maintain balance, cheetahs can make sharp turns if needed. The chase is usually over in less than a minute and if the cheetah fails to make a quick catch, it will often give up rather than waste energy. Another reason a cheetah may give up is because running at such high speeds puts a great deal of strain on the cheetah's body. The temperature within the cheetah reaches such high temperatures that it would be deadly to continue, this is why cheetahs are often seen resting even after they have caught their prey. Roughly half of the chases are successful. The cheetah kills its prey by tripping it during the chase, then biting it on the underside of the throat to suffocate it, for the cheetah is not strong enough to break the necks of the gazelles it mainly hunts. Then the cheetah proceeds to devour its catch as quickly as possible, for it is unable to defend itself against lions and hyenas.

Habitat

The range of the cheetah

Cheetahs are found in the wild primarily in Africa, but in the past their range extended into northern India. Conservationists using camera traps have recently discovered surviving poplations in Iran and are taking steps to protect them. In much of their former range they were domesticated by aristocrats and used to hunt antelopes in much the same way as is still done with members of the greyhound family. Aside from an estimated 200 cheetahs living in Iran (Khorasan Province), the distribution of cheetahs is now limited to Africa. There are 5 subspecies of cheetah in the genus Acinonyx: four in Africa and one in Iran. The endangered subspecies, Acinonyx jubatus venaticus lives in Asia (Iran). In 1990, there were reports in The Times of India of a cheetah sighting in eastern India. There is a chance some cheetahs remain in India, though it is doubtful.There have been sightings of the Asiatic cheetah in southwestern Pakistan (Balochistan province) in the last decade,so there might be small population in Pakistan. The cheetah prefers to live in an open biotope, such as semi- desert, prairie, and thick brush

Genetics

Cheetah mother with cub.

Cheetahs have unusually low genetic variability and high abnormal sperm count. Skin grafts between non-related cheetahs illustrate this point in that there is no rejection of the donor skin. It is thought that they went through a prolonged period of inbreeding following a genetic bottleneck during the last ice age. They probably evolved in Africa during the Miocene epoch (26 million to 7.5 million years ago), before migrating to Asia. New research by a team lead by Warren Johnson and Stephen O’Brien of the Laboratory of Genomic Diversity (National Cancer Institute in Frederick, Maryland, US) has recently placed the last common ancestor of all existing cat species as living in Asia c. 11 million years ago, which may lead to revision and refinement of existing ideas about cheetah evolution. Now extinct species include: Acinonyx pardinensis (Pliocene epoch), much larger than modern cheetahs and found in Europe, India, and China; Acinonyx intermedius (mid- Pleistocene period), found over the same range. The extinct genus Miracinonyx was extremely cheetah-like, but recent DNA analysis has shown that Miracinonyx inexpectatus, Miracinonyx studeri, and Miracinonyx trumani (early to late Pleistocene epoch), found in North America and called the "North American Cheetah" are not true cheetahs, instead being close relatives to the puma.

King Cheetah

The king cheetah was first noted in Zimbabwe in 1926. In 1927, the naturalist Reginald Innes Pocock declared it a separate species, but reversed this decision in 1939 due to lack of evidence. In 1928, a skin purchased by Lord Rothschild was found to be intermediate in pattern between the king cheetah and spotted cheetah and Abel Chapman considered it to be a colour form of the spotted cheetah. 22 such skins were found between 1926 and 1974. Since 1927, king cheetahs were reported 5 more times in the wild. Although strangely marked skins had come from Africa, a live king cheetah was not photographed until 1974 in South Africa's Kruger National Park. Cryptozoologists Paul and Lena Bottriell photographed one during an expedition in 1975. They also managed to obtain stuffed specimens. It appeared larger than a spotted cheetah and its fur had a different texture. There was another wild sighting in 1986 - the first for 7 years. By 1987, 38 specimens had been recorded, many from pelts.

Its species status was resolved in 1981 when king cheetahs were born at the De Wildt Cheetah Center in South Africa. In May 1981, two spotted sisters gave birth there and each litter contained one king cheetah. The sisters had both mated with a wild-caught male from the Transvaal area (where King Cheetahs had been recorded). Further King Cheetahs were later born at the Centre. This mutation has been reported in Zimbabwe, Botswana and in the northern part of South Africa's Transvaal province.

Other Cheetah Colour Morphs

Other rare colour morphs included speckled cheetahs, melanistic cheetahs, albino cheetahs and grayish cheetahs. Most were reported in Indian cheetahs, particularly in captive specimens kept for hunting.

The Moghul Emperor of India, Jahangir, recorded having a white cheetah presented to him in 1608. In the memoirs of Tuzuk-i-Jahangiri, the Emperor says that in the third year of his reign: Raja Bir Singh Deo brought a white cheetah to show me. Although other sorts of creatures, both birds and beasts have white varieties .... I had never seen a white cheetah. Its spots, which are (usually) black, were of a blue colour, and the whiteness of the body also inclined to blue-ishness. This suggests a chinchilla mutation which restricts the amount of pigment on the hair shaft. Although the spots were formed of black pigment, the less dense pigmentation gives a hazy, grayish effect. As well as Jahangir's white cheetah at Agra, a report of "incipient albinism" has come from Beaufort West according to Guggisberg.

In a letter to "Nature in East Africa", HF Stoneham reported a melanistic cheetah (black with ghost markings) in the Trans-Nzoia District of Kenya in 1925. Vesey Fitzgerald saw a melanistic cheetah in Zambia in the company of a spotted cheetah. Red (erythristic) cheetahs have dark tawny spots on a golden background. Cream (isabelline) cheetahs have pale red spots on a pale background. Some desert region cheetahs are unusually pale; probably they are better camouflaged and therefore better hunters and more likely to breed and pass on their paler colouration. Blue (maltese or gray) cheetahs have variously been described as white cheetahs with grey-blue spots (chinchilla) or pale grey cheetahs with darker grey spots (maltese mutation). A cheetah with hardly any spots was shot in Tanzania on 1921 (Pocock), it had only a few spots on the neck and back and these were unusually small.

Woolly Cheetah

Woolly cheetahs were variants of cheetahs that had longer, denser fur. They have been reported several times and were thought to be a separate species. The reports came in the 1800s when unusual specimens were shot rather than captured alive, hence the mutation has apparently vanished. Woolly cheetahs had thicker bodies and stouter limbs than normal cheetahs though this may be an optical illusion caused by the long hair. They had dense, woolly hair especially on the tail and neck where it formed a ruff or mane. The long fur made the normal spotted cheetah pattern indistinct and the animals appeared pale fawn with dark, round blotches. Long hair in cats is due to a recessive (hidden) gene, so the gene may still be present in a few individuals. However, the cheetah gene pool is unusually uniform so the lack of modern longhaired cheetahs means the mutation has probably vanished.

In 1877, Philip Sclater of the Zoological Society of London wrote of a recent acquisition by the zoo: It presents generally the appearance of a cheetah, but is thicker in the body, and has shorter and stouter limbs, and a much thicker tail. When adult it will probably be considerably larger than the cheetah, and is larger even now than our three specimens of that animal. The fur is much more woolly and dense than in the cheetah, as is particularly noticeable on the ears, mane and tail.

The whole of the body is of a pale isabelline colour, rather paler on the belly and lower parts, but covered all over, including the belly, with roundish dark fulvous blotches. There are no traces of the black spots which are so conspicuous in all of the varieties of the cheetah which I have seen, nor of the characteristic black line between the mouth and eye.

Although described as blotched, a painting of the cheetah depicts it as freckled and the artist mistakenly added "eyeliner" markings which were not present in the actual specimen. In 1878, a second woolly cheetah was reported as a preserved specimen in the South African Museum. Both the London and South African specimens had come from Beaufort West. In 1884, a third skin was obtained from the same area, though this had more distinct spots and was a little smaller. By the 1880s, the trophy hunters had eliminated the woolly cheetah.

In Harmsworth Natural History (1910), R Lydekker wrote of the "hunting leopard" or "chita" (old spelling of cheetah) in which he distinguished it from the "normal" cheetah: "The hunting leopard of South Africa has been stated to differ from the Indian animal in its stouter build, thicker tail, and denser and more woolly fur, the longest hairs occurring on the neck, ears, and tail. This woolly hunting leopard was regarded by its describer as a distinct species (Cynaelurus lanius), but it is, at most, only a local race, of which the proper name is C. jubatus guttatus."

Economic importance

Lying cheetah.

Cheetah fur was formerly regarded as a status symbol. Today, cheetahs have a growing economic importance for ecotourism and they are also found in zoos. Because cheetahs are far less aggressive than other big cats, kittens are sometimes sold as pets. This is an illegal trade, because international conventions forbid private ownership of wild animals or species threatened with extinction.

Cheetahs were formerly, and are sometimes still hunted because many farmers believe that they eat livestock. When the species came under threat, numerous campaigns were launched to try to educate farmers and encourage them to conserve cheetahs. Recent evidence has shown that if a cheetah can avoid it they will not attack and eat livestock, preferring their wild prey. However, they have no problem with including farmland as part of their territory, leading to conflict.

Ancient Egyptians often kept them as pets. They were also tamed and trained for hunting. Cheetahs would be taken to hunting fields in low-sided carts or by horseback, hooded and blind folded, and kept on leashes while dogs flushed out their prey. When the prey was near enough, the cheetahs would be released and their blind-folds removed. This tradition was passed on to the ancient Persians and carried to India. This practice continued into the twentieth century by Indian princes. Cheetahs continued to be associated with royalty and elegance, their use as pets spreading just as their hunting skills were. Other such princes and kings kept them as pets, including Gengis Khan and Charlemagne, who boasted of having kept cheetahs within their palace grounds. As recently as the 1930's the Emperor of Abyssinia, Haile Selassie, was often photographed leading a cheetah by a leash.

Conservation status

Cheetah cubs have a high mortality rate due to genetic factors and predation by carnivores in competition with the cheetah, such as the lion and hyena. Some biologists now believe that they are too inbred to flourish as a species.

Cheetahs are included on the IUCN list: vulnerable species (African subspecies threatened, Asiatic subspecies in critical situation) as well as on the US ESA: threatened species - Appendix I of CITES (Convention on International Trade in Endangered Species). Approximately 12,400 cheetahs remain in the wild in 25 African countries; Namibia has the most, with about 2,500. Another 100-200 are thought to remain in Iran. There have been successful breeding programs, including the use of in-vitro fertilization, in zoos around the world.