Onager

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How to read a taxoboxAsiatic wild ass
Khulan am Wasser Abend.jpg
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Perissodactyla
Family: Equidae
Genus: Equus
Subgenus: Asinus
Species: E. hemionus
Binomial name
Equus hemionus
Pallas, 1775

Asiatic wild ass, or Asian wild ass, is the common name for a wild member of the horse family Equidae, Equus hemionus, characterized by distinctive white markings on the anterior part of the rump and on the posterior part of the shoulder and a stripe down the back that is bordered by white. This odd-toed ungulate is found native in Mongolia, China, India, Iran, and Turkmenistan and has been reintroduced to other nations in its former range as well. It is one of several species of asses in the horse family. The Asiatic wild ass also is known as the onager, although this more specifically refers to one of the subspecies, E. h. onager, of Iran.

The Asiatic wild ass are important parts of desert and grassland ecosystems, and while the fast-running adults can outrun most predators, members of the species, notably the young and infirm, are susceptible to predators such as the pack-hunting wolves. The Asiatic wild ass also provides functions for human beings, both directly in the form of meat and also in the form of tourism.

However, like many other large grazing animals (with the notable exception of domesticated species, such as the horse and donkey), its range has contracted greatly under the pressures of hunting and habitat loss. As a species, the Asiatic wild ass is considered to be Endangered, and even the Mongolian khulan subspecies (E. h. hemionus), which represents almost eighty percent of the global population, is at risk and has declined significantly in recent years.

Contents

Overview and description

The Asiatic wild ass (Equus hemionus) is a member of the Equidae, a family of odd-toed ungulate mammals of horses and horse-like animals. There are three basic groups recognized in Equidae—horses, asses, and zebras—although all extant equids are in the same genus of Equus. The Asiatic wild ass is one of three or four extant species of asses, which are placed together in the subgenus Asinus. The other species known as asses are the African wild ass (E. africanus, sometimes E. asinus), donkey or ass (E. asinus), and kiang (E. kiang). The kiang is related to the Asiatic wild ass and in some classifications it is a subspecies of the Asiatic wild ass, listed as E. hemionus kiang.

Asiatic wild asses have a shoulder height of about 108 to 126 centimeters (43-50 inches) (Grzimek et al. 2004), a head-body length of about 2.1 meters (6.9 feet), and a weight from 200 to 290 kilograms (441-639 pounds).

Asiatic wild asses are a little more horse-like than are donkeys, but are short-legged compared to horses. Their coloring varies depending on the season. They are generally reddish-brown in color during the summer, becoming yellowish-brown in the winter months. They have a black stripe bordered in white that extends down the middle of the back. The erect mane is dark in color. They have a white belly and chest and distinctive white markings on the posterior part of the shoulder and anterior part of the rump (Grzimek et al. 2004). The muzzle is white with the area around the nostrils and the lips grayish (Grzimek et al. 2004).

They are notoriously untameable. Equids were used in ancient Sumer to pull wagons around 2600 B.C.E. and are represented as pulling chariots on the Standard of Ur, a Sumarian artifact, at around the same time. While these have been suggested to be Asiatic wild asses, they are now thought to have been domestic African wild asses (Clutton-Brock 1992).

Subspecies

Four or five extant and one extinct subspecies currently are recognized (Moehlman et al. 2008):

  • Mongolian wild ass or Mongolian kulan, Equus hemionus hemionus (Northern Mongolia)
    • Gobi kulan or dziggetai, Equus hemionus luteus, is considered likely to be synonym of E. h. hemionus (Moehlman et al. 2008)
  • Indian wild ass or khur, Equus hemionus khur (India)
  • Turkmenian kulan or Turkmen kulan, Equus hemionus kulan (Turkmenistan, but reintroduced into Kazakhstan, Uzbekistan, and Ukraine)
  • Persian onager or onager, Equus hemionus onager (Iran, introduced in Saudi Arabia)
  • Syrian wild ass, Equus hemionus hemippus (extinct since 1927, formerly from the Arabian Peninsula to Syria)

Distribution and habitat

The four (or five) remaining subspecies are found in limited ranges in Mongolia, China, India, Iran, and Turkmenistan. The species once had a much wider range, including Russia, Kazakhstan, Saudi Arabia, Armenia, Azerbaijan, Turkey, Ukraine, Syria, Lebanon, Jordan, Iraq, Afghanistan, and Pakistan. Populations now have been reintroduced in Kazakhstan, Uzbekistan, southern Israel, and Ukraine, but the populations in Urkraine, Israel, and Saudi Arabia are not the subspecies that originally was found there (Moelhman et al. 2008).

The largest subspecies population is the Mongolian wild ass (E. h. hemionus) in northern Mongolia and adjacent northern China, with an estimate in 2003 at about 18,000 individuals. Southern Mongolia has the largest population of Asiatic wild ass in the world with an estimated 80 percent of the global population. (The kulan population in China may be a seasonal population migrating from Mongolia.) However, this once more widely distributed subspecies has experienced a major population and range size decline and now is found only in the Gobi Desert region. The Indian khur (E. h. khur) likewise once was widespread in India and Pakistan, but now is apparently found only in the Little Rann of Kutch in Gujarat, India, although there are reports of it being found along the India-Pakistan border. This is the second largest subpopulaton with an estimated size of 3,900 in 2004. There are an estimated 1300 Turkmen kulan in Trukmenistan in 2005, and about 600 onagers in Iran (Moelhman et al. 2008)

The Asiatic wild ass inhabits steppe, mountain steppe, desert plains, and semi-desert areas, and are usually found in desert steppe (Moelhman et al. 2008). They can lie in extreme salt desert conditions (Grzimek et al. 2004).

Behavior, diet, and reproduction

Asiatic wild asses are herbivores and tend to be predominately grazers when grass is plentiful, but during the dry season and in drier habitats they browse for a significant part of their diet.

Females and their offspring tend to form relatively small, stable groups, of fewer than five individuals, but there are temporary aggregations and these herds may number up to 1,200 individuals. Breeding is seasonal and gestation time is eleven months. Young are born between April and September, with the births tending to occur over a two to three month span, with a peak between mid June and mid July. The age when females first reproduce is five years, and females typically produce one live foal every three years. The first year survival rate is about fifty percent (Moehlman et al. 2008, Grzimek et al. 2004).

Conservation

The Asiatic wild ass is experiencing numerous threats to its survival, including loss of habitat (from human settlement, cultivation, overgrazing, development activities, salt extraction), poaching for meat and skins, competition with domestic livestock, and competition for water. Poaching is a particularly serious threat. The Turkmen kulan (Equus hemionus kulan) suffered a catastropic decline in the late 1990s as a result of poaching for the sale of meat and the Mongolian kulan (E. h. hemionus) currently is suffering from illegal hunting for meat and skins (Moehlman et al. 2008).

The Asiatic wild ass is listed as Endangered, since its population is estimated to have declined by more than fifty percent over the past 16 years and is expected to decline by more than fifty percent over the next 10 to 21 years. Its historic range has been greatly reduced and it is now extinct in many nations where it once was found. The largest remaining subspecies, the Mongolian khulan (E. h. hemionus) declined from an estimated population size of 43,165 in 1997 to 18,411 +/- 898 in 2003 (Moehlman et al. 2008).

The Asiatic wild ass is legally protected in Mongolia, Iran, India, and Turkemistan. There have been successful reintroduction projects in a number of nations, including Kazakhstan, Uzbekistan, Turkmenistan, Iran, Israel, Saudi Arabia, and Ukraine. The risk of a healthy population being quickly reduced in numbers is evident in the case of the Badkhyz Preserve in Turkmenistan; a population that had been only 200 animals in the mid-1940s grew to 6,000 animals by 1993 when they were protected, but then they were killed in large numbers in the late 1990s when they migrated from the reserve in the summer months and were soon down to about 600 animals (Moehlman et al. 2008).

References

  • Clutton-Brock, J. 1992. Horse Power: A History of the Horse and the Donkey in Human Societies. Harvard University Press. ISBN 9780674406469.
  • Duncan, P. (ed.). 1992. Zebras, Asses, and Horses: An Action Plan for the Conservation of Wild Equids. IUCN/SSC Equid Specialist Group. Gland, Switzerland: IUCN.
  • Grzimek, B., D. G. Kleiman, V. Geist, and M. C. McDade, Grzimek's Animal Life Encyclopedia. Detroit: Thomson-Gale, 2004. ISBN 0307394913.
  • Moehlman, P. D. 2004. Equidae. In B. Grzimek, D. G. Kleiman, V. Geist, and M. C. McDade, Grzimek's Animal Life Encyclopedia. Detroit: Thomson-Gale, 2004. ISBN 0307394913.
  • Moehlman, P. D., N. Shah, and C. Feh. 2008. Equus hemionus. In IUCN, 2008 IUCN Red List of Threatened Species. Database entry includes justification for why this species is Endangered. Retrieved February 7, 2009.
  • Savage, R. J. G., and M. R. Long. 1986. Mammal Evolution: An Illustrated Guide. New York: Facts on File. ISBN 081601194X.


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