| Cheetah[1] Temporal range: Late Pliocene to Recent |
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|---|---|
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Family: | Felidae |
| Genus: | Acinonyx |
| Species: | A. jubatus |
| Binomial name | |
| Acinonyx jubatus (Schreber, 1775) |
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| Type species | |
| Acinonyx venator Brookes, 1828 (= Felis jubata, Schreber, 1775) by monotypy |
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| Subspecies | |
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See text. |
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| The range of the cheetah | |
The cheetah (Acinonyx jubatus) is a large-sized feline (family Felidae) inhabiting most of Africa and parts of the Middle East. The cheetah is the only extant member of the genus Acinonyx, most notable for modifications in the species' paws. As such, it is the only felid with non-retractable claws and pads that, by their scope, disallow gripping (therefore cheetahs cannot climb vertical trees, although they are generally capable of reaching easily accessible branches). The cheetah, however, achieves by far the fastest land speed of any living animal—between 112 and 120 km/h (70 and 75 mph)[3][4] in short bursts covering distances up to 500 m (1,600 ft), and has the ability to accelerate from 0 to over 100 km/h (62 mph) in three seconds.[5]
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The word "cheetah" is derived from the Sanskrit word citrakāyaḥ, meaning "variegated", via the Hindi चीता cītā.[6]
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.
The cheetah has unusually low genetic variability. This is accompanied by a very low sperm count, motility, and deformed flagella.[7] Skin grafts between unrelated cheetahs illustrate the former point in that there is no rejection of the donor skin. It is thought that the species went through a prolonged period of inbreeding following a genetic bottleneck during the last ice age. This suggests that genetic monomorphism did not prevent the cheetah from flourishing across two continents for thousands of years.[8]
The cheetah likely evolved in Africa during the Miocene epoch (26 million to 7.5 million years ago), before migrating to Asia. Recent research has placed the last common ancestor of all existing populations as living in Asia 11 million years ago, which may lead to revision and refinement of existing ideas about cheetah evolution.[9]
The now-extinct species include: Acinonyx pardinensis (Pliocene epoch), much larger than the modern cheetah 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 cougar.[10]
Although many sources list six or more subspecies of cheetah, the taxonomic status of most of these subspecies is unresolved[says who?]. Acinonyx rex—the king cheetah (see below)—was abandoned as a subspecies after it was discovered that the variation was caused by a single recessive gene. The subspecies Acinonyx jubatus guttatus, the woolly cheetah, may also have been a variation due to a recessive gene. Some of the most commonly recognized subspecies include:[11]
The cheetah's chest is deep and its waist is narrow. The coarse, short fur of the cheetah is tan with round black spots measuring from 2 to 3 cm (0.79 to 1.2 in) across, affording it some camouflage while hunting. There are no spots on its white underside, but the tail has spots, which merge to form four to six dark rings at the end. The tail usually ends in a bushy white tuft. The cheetah has a small head with high-set eyes. Black "tear marks" running from the corner of its eyes down the sides of the nose to its mouth keep sunlight out of its eyes and aid in hunting and seeing long distances. Although it can reach high speeds, its body cannot stand long distance running, because it is more suited to short bursts of speed.
The adult cheetah weighs from 35 to 72 kg (77 to 160 lb). Its total head-and-body length is from 110 to 150 cm (43 to 59 in), while the tail can measure 60 to 84 cm (24 to 33 in) in length.[12][13][14] Cheetahs are 66 to 94 cm (26 to 37 in) tall at the shoulder. Males tend to be slightly larger than females and have slightly bigger heads, but there is not a great variation in cheetah sizes and it is difficult to tell males and females apart by appearance alone. Compared to a similarly sized leopard, the cheetah is generally shorter-bodied, but is longer tailed and taller (it averages about 90 cm (35 in) tall) and so it appears more streamlined.
Some cheetahs have a rare fur pattern mutation of larger, blotchy, merged spots. Known as "king cheetahs," they were once thought to constitute a separate subspecies but are in fact African cheetahs; their unusual fur pattern is the result of a single recessive gene.[15] The "king cheetah" has only been seen in the wild a handful of times, but it has been bred in captivity.
The cheetah's paws have semi-retractable claws (known only in three other cat species: the fishing cat, the flat-headed cat and the Iriomote cat), offering extra grip in its high-speed pursuits. 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 dewclaw itself is much shorter and straighter than that of other cats.
Adaptations that enable the cheetah to run as fast as it does include large nostrils that allow for increased oxygen intake, and an enlarged heart and lungs that work together to circulate oxygen efficiently. During a typical chase, its respiratory rate increases from 60 to 150 breaths per minute.[7] While running, in addition to having good traction due to its semi-retractable claws, the cheetah uses its tail as a rudder-like means of steering to allow it to make sharp turns, necessary to outflank prey animals that often make such turns to escape.
Unlike "true" big cats, the cheetah can purr as it inhales, but cannot roar. By contrast, the big cats can roar but cannot purr, except while exhaling. The cheetah is still considered by some to be the smallest of the big cats. While it is often mistaken for the leopard, the cheetah does have distinguishing features, such as the aforementioned long "tear-streak" lines that run from the corners of its eyes to its mouth, and spots that are not "rosettes". The thinner body frame of the cheetah is also very different from that of the leopard.
The cheetah is a vulnerable species. Of all the big cats, it is the least able to adapt to new environments. It has always proved difficult to breed in captivity, although recently a few zoos have managed to succeed at this. Once widely hunted for its fur, the cheetah now suffers more from the loss of both habitat and prey.
The cheetah was formerly considered to be particularly primitive among the cats and to have evolved approximately 18 million years ago. New research, however, suggests the last common ancestor of all 40 existing species of felines lived more recently than that—about 11 million years ago. The same research indicates the cheetah, while highly derived morphologically, is not of particularly ancient lineage, having separated from its closest living relatives (Puma concolor, the cougar, and Puma yaguarondi, the jaguarundi) around five million years ago.[10] These felids have not changed appreciably since they first appeared in the fossil record.
The king cheetah is a rare mutation of cheetah characterized by a distinct fur pattern. It was first noted in what was then Southern Rhodesia (modern-day 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, but in 1928, a skin purchased by Walter Rothschild was found to be intermediate in pattern between the king cheetah and spotted cheetah and Abel Chapman considered it to be a color form of the spotted cheetah. Twenty-two such skins were found between 1926 and 1974. Since 1927, the king cheetah was reported five 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 in seven years. By 1987, thirty-eight specimens had been recorded, many from pelts.
Its species status was resolved in 1981 when king cheetahs were born at the De Wildt Cheetah and Wildlife Centre 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. It has been known to exist in Zimbabwe, Botswana and in the northern part of South Africa's Transvaal province. A recessive gene must be inherited from both parents for this pattern to appear, which is one reason why it is so rare.
Other rare color morphs of the species include speckles, melanism, albinism and gray coloration. Most have been reported in Indian cheetahs, particularly in captive specimens kept for hunting.
The Mughal Emperor of India, Jahangir, recorded having a white cheetah presented to him in 1608. In the memories of Tuzk-e-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", H. F. 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 coloration. Blue (Maltese or grey) 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 in 1921 (Pocock); it had only a few spots on the neck and back, and these were unusually small.
There are several geographically isolated populations of cheetah, all of which are found in Africa or southwestern Asia. A small population (estimated at about fifty) survive in the Khorasan Province of Iran, where conservationists are taking steps to protect them.[16]. There have also been several unconfirmed reports of Asiatic Cheetahs in the Balochistan province of Pakistan, with at least one dead animal being discovered recently. [17]
The cheetah thrives in areas with vast expanses of land where prey is abundant. The cheetah likes to live in an open biotope, such as semidesert, prairie, and thick brush, though it can be found in a variety of habitats. In Namibia, for example, it lives in grasslands, savannahs, areas of dense vegetation, and mountainous terrain.
In much of its former range, the cheetah was tamed by aristocrats and used to hunt antelopes in much the same way as is still done with members of the greyhound group of dogs.
Females reach maturity in twenty to twenty-four months, and males around twelve months (although they do not usually mate until at least three years old), and mating occurs throughout the year. A study of cheetahs in the Serengeti showed females are sexually promiscuous and often have cubs by many different males.[18]
Females give birth to up to nine cubs after a gestation period of ninety to ninety-eight days, although the average litter size is three to five. Cubs weigh from 150 to 300 g (5.3 to 11 oz) at birth. Unlike some other cats, the cheetah is born with its characteristic spots. Cubs are also born with a downy underlying fur on their necks, called a mantle, extending to mid-back. This gives them a mane or Mohawk-type appearance; this fur is shed as the cheetah grows older. It has been speculated this mane gives a cheetah cub the appearance of the honey badger (ratel), to scare away potential aggressors.[19] Cubs leave their mother between thirteen and twenty months after birth. Life span is up to twelve years in the wild, but up to twenty years in captivity.
Unlike males, females are solitary and tend to avoid each other, though some mother/daughter pairs have been known to be formed for small periods of time. The cheetah has a unique, well-structured social order. Females live alone, except when they are raising cubs and they raise their cubs on their own. The first eighteen months of a cub's life are important; cubs must learn many lessons, because survival depends on knowing how to hunt wild prey species and avoid other predators. At eighteen months, the mother leaves the cubs, who then form a sibling ("sib") group that will stay together for another six months. At about two years, the female siblings leave the group, and the young males remain together for life.
Males are often social and may group together for life, usually with their brothers in the same litter; although if a cub is the only male in the litter then two or three lone males may form a group, or a lone male may join an existing group. These groups are called coalitions. In one Serengeti, 41% of the adult males were solitary, 40% lived in pairs and 19% lived in trios.[20]
A coalition is six times more likely to obtain an animal territory than a lone male, although studies have shown that coalitions keep their territories just as long as lone males— between four and four and a half years.
Males are territorial. Females' home ranges can be very large and a territory including several females' ranges is impossible to defend. Instead, males choose the points at which several of the females' home ranges overlap, creating a much smaller space, which can be properly defended against intruders while maximizing the chance of reproduction. Coalitions will try their best to maintain territories to find females with whom they will mate. The size of the territory also depends on the available resources; depending on the part of Africa, the size of a male's territory can vary greatly from 37 to 160 km2 (14 to 62 sq mi).
Males mark their territory by urinating on objects that stand out, such as trees, logs, or termite mounds. The whole coalition contributes to the scent. Males will attempt to kill any intruders, and fights result in serious injury or death.
Unlike males and other felines, females do not establish territories. Instead, the area they live in is termed a home range. These overlap with other females' home ranges, often those of their daughters, mothers, or sisters. Females always hunt alone, although cubs will accompany their mothers to learn to hunt once they reach the age of five to six weeks.
The size of a home range depends entirely on the availability of prey. Cheetahs in southern African woodlands have ranges as small as 34 km2 (13 sq mi), while in some parts of Namibia they can reach 1,500 km2 (580 sq mi).
The cheetah cannot roar, but does have the following vocalizations:
The cheetah is a carnivore, eating mostly mammals under 40 kg (88 lb), including the Thomson's gazelle, the Grant's gazelle, the springbok and the impala. The young of larger mammals such as wildebeests and zebras are taken at times, and adults too, when the cats hunt in groups. Guineafowl and hares are also prey. 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 evening when it is not so hot, but there is still enough light.
The cheetah hunts by vision rather than by scent. Prey is stalked to within 10–30 m (33–98 ft), then chased. This is usually over in less than a minute, and if the cheetah fails to make a catch quickly, it will give up. The cheetah has an average hunting success rate of around 50%.[7]
Running at speeds between 112 and 120 km/h (70 and 75 mph) puts a great deal of strain on the cheetah's body. When sprinting, the cheetah's body temperature becomes so high that it would be deadly to continue; this is why the cheetah is often seen resting after it has caught its prey. If it is a hard chase, it sometimes needs to rest for half an hour or more. The cheetah kills its prey by tripping it during the chase, then biting it on the underside of the throat to suffocate it; the cheetah is not strong enough to break the necks of the four-legged prey it mainly hunts. The bite may also puncture a vital artery in the neck. Then the cheetah proceeds to devour its catch as quickly as possible before the kill is taken by stronger predators.
The diet of a cheetah is dependent upon the area in which it lives. For example, on the East African plains, its preferred prey is the Thomson's gazelle. This small antelope is shorter than the cheetah (about 53–67 cm (21–26 in) tall and 70–107 cm (28–42 in) long), and also cannot run faster than the cheetah (only up to 80 km/h (50 mph)), which combine to make it an appropriate prey. Cheetahs look for individuals which have strayed some distance from their group, and do not necessarily seek out old or weak ones.
Despite their speed and hunting prowess, cheetahs are largely outranked by other large predators in most of their range. Because they have evolved for short bursts of extreme speed at the expense of their power, they cannot defend themselves against most of Africa's other predator species. They usually avoid fighting and will surrender a kill immediately to even a single hyena, rather than risk injury. Because cheetahs rely on their speed to obtain their meals, any injury that slows them down could essentially be life threatening.
A cheetah has a 50% chance of losing its kill to other predators.[7] Cheetahs avoid competition by hunting at different times of the day and by eating immediately after the kill. Due to the reduction in habitat in Africa, cheetahs in recent years have faced greater pressure from other native African predators as available range declines.
The cheetah's mortality is very high during the early weeks of its life; up to 90% of cheetah cubs are killed during this time by lions, leopards, hyenas, wild dogs, or even by eagles. Cheetah cubs often hide in thick brush for safety. Mother cheetahs will defend their young and are at times successful in driving predators away from their cubs. Coalitions of male cheetahs can also chase away other predators, depending on the coalition size and the size and number of the predator. Because of its speed, a healthy adult cheetah has few enemies.[25]
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. Cheetahs are far less aggressive than other felids and can be tamed, so cubs are sometimes illegally sold as pets.
Cheetahs were formerly, and sometimes still are, 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 cheetahs will not attack and eat livestock if they can avoid doing so, as they prefer their wild prey. However, they have no problem with including farmland as part of their territory, leading to conflict.
Ancient Egyptians often kept cheetahs as pets, and also tamed and trained them for hunting. (But not domesticated i.e., bred under human control.) Cheetahs would be taken to hunting fields in low-sided carts or by horseback, hooded and blindfolded, and kept on leashes while dogs flushed out their prey. When the prey was near enough, the cheetahs would be released and their blindfolds removed. This tradition was passed on to the ancient Persians and brought to India, where the practice was continued by Indian princes into the twentieth century. 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 Genghis Khan and Charlemagne, who boasted of having kept cheetahs within their palace grounds. Akbar the Great, ruler of the Mughal Empire from 1556 to 1605, kept as many as 1000 cheetahs.[7] As recently as the 1930s the Emperor of Ethiopia, Haile Selassie, was often photographed leading a cheetah by a leash.
Cheetah cubs have a high mortality rate due to predation by other carnivores, such as the lion and hyena, and perhaps genetic factors. It has been suggested that the low genetic diversity of cheetahs is a cause of poor sperm, birth defects, cramped teeth, curled tails, and bent limbs. Some biologists even believe that they are too inbred to flourish as a species.[26] Note, however, that they lost most of their genetic diversity thousands of years ago (see the beginning of this article), and yet seem to have only been in decline in the last century or so, suggesting factors other than genetics are mainly responsible.
Cheetahs are included on the International Union for Conservation of Nature (IUCN) list of vulnerable species (African subspecies threatened, Asiatic subspecies in critical situation) as well as on the US Endangered Species Act: threatened species - Appendix I of CITES (Convention on International Trade in Endangered Species). Approximately 12,400 cheetahs remain in the wild in twenty-five African countries; Namibia has the most, with about 2,500. Another fifty to sixty critically endangered Asiatic cheetahs are thought to remain in Iran. There have been successful breeding programs, including the use of in vitro fertilisation, in zoos around the world.
Founded in Namibia in 1990, the Cheetah Conservation Fund's mission is to be the world’s resource charged with protecting the cheetah and ensuring its future on our planet. The organization works with all stakeholders within the cheetah’s ecosystem to develop best practices in research, education and ecology and create a sustainable model from which all other species, including people, will benefit.
The South African Cheetah Conservation Foundation has close links and assists in training and sharing program successes with other countries where cheetahs live, including Botswana, South Africa, Zimbabwe, Iran and Algeria. The organization's international program includes distributing materials, lending resources and support, and providing training through Africa and the rest of the world.
Cheetahs have been known to exist in India for a very long time, but as a result of hunting and other causes, cheetahs have been extinct in India since the 1940s. A captive propagation project has been proposed. Minister of Environment and Forests Jairam Ramesh told the Rajya Sabha on 7 July 2009, "The cheetah is the only animal that has been described extinct in India in the last 100 years. We have to get them from abroad to repopulate the species." He was responding to a call for attention from Rajiv Pratap Rudy of the Bharatiya Janata Party (BJP). "The plan to bring back the cheetah, which fell to indiscriminate hunting and complex factors like a fragile breeding pattern is audacious given the problems besetting tiger conservation." Two naturalists, Divya Bhanusinh and MK Ranjit Singh, suggested importing cheetahs from Africa, after which they will be bred in captivity and, in time, released in the wild.[27]