The cheetah (Acinonyx jubatus) is a large feline (family Felidae, subfamily Felinae) inhabiting most of Africa and parts of the Middle East. It is the only extant member of the genus Acinonyx. The cheetah can run faster than any other land animal— as fast as 96.5 to 104 km/h (60.0 to 65 mph) 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.
This cat is also notable for modifications in the species' paws. It is one of the few felids with semi-retractable claws.
Genetics, evolution, and classification
The genus name, Acinonyx, means "no-move-claw" in Greek, while the species name, jubatus, means "maned" or "crested" in Latin, a reference to the dorsal crest found in cheetah cubs.The cheetah has unusually low genetic variability. This is accompanied by a very low sperm count, motility, and deformed flagella. 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.
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.
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.
Subspecies
Although many sources list six or more subspecies of cheetah, the taxonomic status of most of these subspecies is unresolved. Acinonyx rex—the king cheetah—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:- Asiatic cheetah (Acinonyx jubatus venaticus): Asia (Afghanistan, India, Iran, Iraq, Israel, Jordan, Oman, Pakistan, Saudi Arabia, Syria, Russia)
- Northwest African cheetah (Acinonyx jubatus hecki): Northwest Africa (Algeria, Djibouti, Egypt, Mali, Mauritania, Morocco, Niger, Tunisia) and western Africa (Benin, Burkina Faso, Ghana, Mali, Mauritania, Niger, and Senegal)
- Acinonyx jubatus raineyii: eastern Africa (Kenya, Somalia, Tanzania, and Uganda)
- Acinonyx jubatus jubatus: southern Africa (Angola, Botswana, Democratic Republic of the Congo, Mozambique, Malawi, South Africa, Tanzania, Zambia, Zimbabwe and Namibia)
- Acinonyx jubatus soemmeringii: central Africa (Cameroon, Chad, Central African Republic, Ethiopia, Nigeria, Niger, and Sudan)
- Acinonyx jubatus velox
Range and habitat
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.It is possible, though doubtful, that some cheetahs remain in India.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.
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.
Reproduction and behavior
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.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. 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.
Territories
Males
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.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.
Females
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).
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