субота, 20. децембар 2008.

Cheetah (Acinonyx jubatus) part II

Cheetah (Acinonyx jubatus)

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% - half of its chases result in failure. Running at speeds up to 112 km/h (70 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, for 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 58–70 cm (23–28 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. More than half of the cheetah cubs are killed by lions, hyenas, and leopards.

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 and a very low sperm count, which also suffers from low motility and deformed flagellae. Skin grafts between non-related cheetahs illustrate this point in that there is no rejection of the donor skin. It is thought that it went through a prolonged period of inbreeding following a genetic bottleneck during the last ice age. It probably evolved in Africa during the Miocene epoch (26 million to 7.5 million years ago), before migrating to Asia. New research by a team led by Warren Johnson and Stephen O'Brien of the Laboratory of Genomic Diversity (National Cancer Institute in Frederick, Maryland, United States) has recently placed the last common ancestor of all existing cat species as living in Asia 11 million years ago, which may lead to revision and refinement of existing ideas about cheetah evolution. 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.


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. Other populations have been elevated to subspecies level, and there are again 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 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
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 big cats and can be tamed, so cubs are sometimes illegaly 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. 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. Cheetah cubs have a high mortality rate due to genetic factors and predation by carnivores in competition with the cheetah, such as the lion and hyena. Recent inbreeding causes cheetahs to share very similar genetic profiles. This has led to poor sperm, birth defects, cramped teeth, curled tails, and bent limbs. Some biologists now believe that they are too inbred to flourish as a species. 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 an internationally recognized centre of excellence in research and education on cheetahs and their eco-systems, working with all stakeholders to achieve best practice in the conservation and management of the world's cheetahs. The CCF has also set stations throughout South Africa in order to keep the conservation effort going. The Cheetah Conservation Foundation, a South African based organisation, was set up in 1993 for cheetah protection.

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