Cheetah

The cheetah (Acinonyx jubatus) is a large feline (family Felidae, subfamily Felinae) inhabiting most of Africa and parts of Iran. It is the only extant member of the genusAcinonyx. The cheetah can run faster than any other land animal— as fast as 112 to 120 km/h (70 to 75 mph) in short bursts covering distances up to 500 m (1,600 ft), and has the ability to accelerate from 0 to 100 km/h (62 mph) in three seconds.

Its main hunting strategy is to run down swift prey such as various antelope species and hares. Almost every facet of the cheetah's anatomy has evolved to maximise its success in the chase, the result of an evolutionary arms race with its prey. Due to this specialisation, however, the cheetah is poorly equipped to defend itself against other large predators, with speed being its main means of defence.

Etymology

The word "cheetah" is derived from the Sanskrit word citrakāyaḥ, meaning "variegated", from the Hindi 'चीता' (cītā)

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 geneticvariability. This is accompanied by a very low sperm count, motility, and deformedflagella. 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 agenetic 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

 

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, Bangladesh, India, Iran, Iraq, Israel, Jordan, Oman,Pakistan, Saudi Arabia, Syria, Russia) Current range is in Iran. Extinct in other Asian countries.

·         Northwest African cheetah (Acinonyx jubatus hecki): Northwest Africa (Algeria, Mali, Mauritania, Morocco, Niger,Tunisia) and western Africa (Benin, Burkina Faso, Ghana, Mali, Mauritania, Nigeria, and Senegal)

·         Tanzanian cheetah (Acinonyx jubatus raineyii): Eastern Africa (Kenya, Somalia, Tanzania, and Uganda)

·         South African cheetah (Acinonyx jubatus jubatus): southern Africa (Angola, Botswana, Democratic Republic of the Congo, Mozambique, Malawi, Namibia, South Africa, Tanzania, Zambia and Zimbabwe) Introduced in Swaziland.

·         Sudan cheetah (Acinonyx jubatus soemmeringii): Northeast Africa (Djibouti, Egypt, Eritrea, Ethiopia, Libya, Somalia,South Sudan and Sudan) and central Africa (Cameroon, Chad, Central African Republic, Nigeria, and Niger)

·         Description

·         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 1.18 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. Its thin and fragile body make it well-suited to short bursts of high speed, but not to long-distance running.

·         Agility, rather than raw speed, accounts for much of the cheetah's ability to catch prey. Cheetahs can accelerate four times as fast as a human (thanks to greater muscle power) and can slow down by 14 kilometers per hour in one stride. They can hunt successfully in densely vegetated areas.

·         The adult cheetah weighs from 21 to 72 kg (46 to 159 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. 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. 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, with the exception of the dewclaw, the claws are always visible. The dewclaw 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. 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.

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

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.

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.

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.