Cheetah

The cheetah (Acinonyx jubatus) is a member of the cat family (Felidae) that is unique for making up in speed and stealth what it lacks in climbing abilities. As such, it is placed in its own genus, Acinonyx. It is the fastest of all land animals and can reach speeds between 112 kilometres per hour (70 mph) and 120 kilometres per hour (75 mph) in short bursts up to 460 metres (500 yd), and has the ability to accelerate from 0 to 110 kilometres per hour (68 mph) in three seconds, more quickly than most supercars.

The word "cheetah" is derived from the Sanskrit word chitrakāyaḥ, meaning "variegated body", via the Hindi

Description

The cheetah has a slender, long-legged body with blunt semi-retractable claws. Its chest is deep and its waist is narrow. The coarse, short fur of the cheetah is tan with round black spots measuring from 2 centimetres (0.79 in) to 3 centimetres (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" run from the corner of its eyes down the sides of the nose to its mouth to keep sunlight out of its eyes and to aid in hunting and seeing long distances.

The adult animal weighs from 40 kilograms (88 lb) to 65 kilograms (140 lb). Its total body length is from 115 centimetres (45 in) to 135 centimetres (53 in), while the tail can measure up to 84 centimetres (33 in) in length. 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 centimetres (35 in) tall) and so it appears more streamlined.

Some cheetahs also have a rare fur pattern mutation: cheetahs with larger, blotchy, merged spots are known as 'king cheetahs'. It was once thought to be a separate subspecies, but it is merely a mutation of the African cheetah. 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 the cat 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 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. 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 who 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. However, 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. The body frame of the cheetah is also very different from that of the leopard, most notably so in its thinner and longer tail, and unlike the leopard, its spots are not arranged into rosettes.

The cheetah is a vulnerable species. Out 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 been successful. 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 puts the last common ancestor of all 40 existing species of feline more recently, at 11 million years. The same research indicates that the cheetah, while highly derived morphologically, is not a particularly ancient lineage, having separated from its closest living relatives (the cougar Puma concolor and the jaguarundi Puma yaguarondi) around 5 million years ago.

Subspecies

For a short time it was thought that there were six subspecies of cheetah, but Acinonyx rex - the king cheetah (see below) - was abandoned after it was discovered the variation was only a recessive gene. The subspecies Acinonyx jubatus guttatus - the woolly cheetah - may also have been a variation due to a recessive gene. There are six subspecies recognized:

• Asiatic Cheetah (Acinonyx jubatus venaticus): northern Africa (Algeria, Djibouti, Egypt, Mali, Mauritania, Morocco, Niger, Tunisia and Western Sahara) and Asia (Afghanistan, India, Iran, Iraq, Israel, Jordan, Oman, Pakistan, Saudi Arabia, Syria, Russia and the Commonwealth of Independent States)
• Northwest African Cheetah (Acinonyx jubatus hecki): 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 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