North American Cheetah
The cheetah is a large feline 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 in short bursts covering distances up to, and has the ability to accelerate from O to 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. Etymology The word “cheetah” is derived from the Sanskrit word meaning “variegated”, via the Hindi . 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 enetic 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, 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, much larger than the modern cheetah and found in Europe, India, and China; Acinonyx intermedius, 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, 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 : Asia . Current range is in Iran, Pakistan and Afghanistan. Extinct in other Asian countries. Northwest African cheetah : Northwest Africa and western Africa Acinonyx Jubatus raineyii: eastern Africa Acinonyx Jubatus Jubatus: southern Africa Acinonyx Jubatus soemmeringii: central Africa Acinonyx Jubatus velox Description The cheetah’s chest is deep and its waist is narrow.
The coarse, short fur of the heetah is tan with round black spots measuring from across, affording it some 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 bility to catch prey. Cheetahs can accelerate four times as fast as a human and can slow down by 14 kilometers per hour in one stride. They can hunt successfully in dense forests. The adult cheetah weighs from . Its total head-and-body length is from, while the tail can measure in length. Cheetahs are 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 horter-bodied, but is longer tailed and taller 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, offering extra grip in its high-speed pursuits.
The ligament structure of the heetah’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.
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. However, new research suggests the last common ancestor of all 40 existing species of felines lived more recently than about 11 million years ago. The same research indicates that the cheetah, while highly derived morphologically, is not of particularly ancient lineage, having separated from its closest living relatives around