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Lifespan, longevity, and ageing

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Maximum longevity: 26.2 years (captivity) Observations: Record longevity in captivity is 26.2 years (Richard Weigl 2005).
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Reproduction

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Equus hemionus are monogamous. Stallions tend to stay with the mare and foal year-round. (Feh et al, 2001)

Mating System: monogamous

Less than half of the foals born survive through the first year. (Feh et al, 2001)

Breeding season: April to October

Range number of offspring: 1 (high) .

Average number of offspring: 0.5.

Average gestation period: 11-12 months.

Average weaning age: 12-24 months.

Average age at sexual or reproductive maturity (female): 3-4 years.

Average age at sexual or reproductive maturity (male): 3-4 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous

Average gestation period: 339 days.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (male)
Sex: male:
1187 days.

Average age at sexual or reproductive maturity (female)
Sex: female:
1157 days.

Other than predator defense by the male, the mare mostly raises the foal. (Feh et al, 2001)

Parental Investment: male parental care ; female parental care

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Untitled

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Substantial competition occurs between wild asses and domestic herds. The habitat of E. hemionus is often restricted from the optimal to the most arid parts of an area by this competition. (Glenn, 1999)

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Bradley Reuter, University of Michigan-Ann Arbor
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Behavior

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Perception Channels: tactile ; chemical

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Bradley Reuter, University of Michigan-Ann Arbor
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Conservation Status

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The Syrian wild ass (E. hemionus hemippus) went extinct in 1927. The subspecies found in southern Mongolia (E. hemionus hemionus) contains several thousand individuals. All of the other subspecies exist in the hundreds. Conservation status varies from subspecies to subspecies. (Reading et al, 2001)

The largest threat to all of the six subspecies is competition with livestock. The species is desired by nomadic livestock herders for harvesting.

US Federal List: endangered

CITES: appendix i

IUCN Red List of Threatened Species: critically endangered

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Benefits

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The protected status of the Asian wild ass has been challenged recently by nomadic herders and other farmers in Mongolia. They believe populations in southern Mongolia are becoming too large. The Asian wild ass competes with domestic grazers for water and food resources. (Reading et al., 2001)

Negative Impacts: crop pest

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Benefits

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During the first half of the 1900s, Asian wild asses were hunted for meat and for their coats. (Glenn, 1999)

Positive Impacts: food

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Trophic Strategy

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The Asian wild ass is strictly herbivorous. They tend to eat perennial grasses (noncotyledons) that are of species of Stipa or Agropyron. They also eat herbs and bark. (Glenn, 1999)

Plant Foods: leaves; wood, bark, or stems

Primary Diet: herbivore (Folivore )

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Bradley Reuter, University of Michigan-Ann Arbor
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Distribution

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In the late Pleistocene, Equus hemionus flourished as far east as West Germany. Currently, at least one subspecies has been found in Russia, China, Iran, and India. However, the major population (over half the total number) of E. hemionus is found in southern Mongolia. (Feh et al, 2001)

Biogeographic Regions: palearctic (Native ); oriental (Native )

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Bradley Reuter, University of Michigan-Ann Arbor
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Habitat

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E. hemionus prefers flat country. It primarily grazes and rests on highland or lowland desert, semidesert or steppe. They are never found more than 30 km from a permanent oasis or spring. (Glenn, 1999)

Habitat Regions: temperate

Terrestrial Biomes: desert or dune

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Bradley Reuter, University of Michigan-Ann Arbor
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Life Expectancy

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In captivity, Asian wild asses have lived for 26 years. The oldest found specimen in the wild was 12-14 years old. Most E. hemionus live between four and eight years. A majority of these die between four and six years old, not long after entering sexual maturity. (Feh et al, 2001)

Range lifespan
Status: wild:
14 (high) years.

Range lifespan
Status: captivity:
26 (high) years.

Typical lifespan
Status: wild:
4 to 8 years.

Average lifespan
Status: captivity:
38.8 years.

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Morphology

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The color of the Asian wild ass varies depending on distribution and season. As a rule, they are reddish brown in the summer and lighten to yellowish brown in the winter. The underneath part of the animals is white or buff. These asses are characterized by a thick black stripe with white edges that runs down the middle of their backs. They also have small feet and short legs. Individuals may be 1-1.4 m tall at the shoulders. (Glenn, 1999)

Range mass: 200 to 260 kg.

Range length: 1.98 to 2.44 m.

Other Physical Features: endothermic ; bilateral symmetry

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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Bradley Reuter, University of Michigan-Ann Arbor
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Associations

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E. hemionus has a well-developed strategy for anti-predator defense. Stallions from more than one family group cooperate to chase off predators. The frequent occurrence of large groups aids this ability. Wolves are the only known predator of the Asian wild ass other than humans. (Feh et al, 2001)

Known Predators:

  • gray wolves (Canis lupus)
  • humans (Homo sapiens)
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Reuter, B. 2002. "Equus hemionus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Equus_hemionus.html
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Bradley Reuter, University of Michigan-Ann Arbor
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Biology

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The Asiatic wild ass eats grasses when available, but will browse on shrubs and trees at other times or in drier habitats (7). It has also been seen feeding on seed pods and breaking up woody vegetation with its hooves to get at more succulent herbs growing at the base of woody plants (6). During spring and summer in Mongolia, the succulent plants of the Zygophyllaceae family form an important component of the diet of the Mongolian wild ass (5). This subspecies is also known to eat snow in winter as a substitute for water (6). At other times when natural water points are unavailable, the Mongolian wild ass will dig holes in dry riverbeds to access sub-surface water. The water holes dug by the wild asses are often subsequently visited by domestic livestock, as well as other wild animals (5) (6). Breeding is seasonal, the gestation period in this species is 11 months, and most births occur from April to September. Females with young tend to form groups of up to five females. Males have been observed holding harems of females, but in other studies they defend territories that attract females. It is likely that differences in behaviour and social structure are the result of changes in climate, vegetation cover, predation and hunting (6). In Mongolia alone, the wild ass seems to adopt harem type social groups in the southwest and territorial based social groups in the south and southeast (5). However, further research is needed to properly understand the dynamics underlying the social behaviour of this species (1) (5).
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Conservation

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The Asiatic wild ass does occur in a number of protected sites where targeted conservation action has been taken. Domestic animals have been removed from some protected areas, and artificial watering holes have been made. Hay is provided for the species and there are hefty fines for poaching. Moreover, the species is legally protected in many of the countries in which it occurs (6). The priority for future conservation measures is: to ensure the protection of this species in particularly vulnerable parts of its range; to encourage the involvement of local people in the conservation of the Asiatic wild ass; and to conduct further research into the behaviour, ecology and taxonomy of the species (1). Fortunately several Asiatic wild ass research programmes considering these issues are already underway (5) (6).
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Description

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The Asiatic wild ass is the most horse-like of all the species of ass (4). The general colour of its coat varies with the seasons, appearing light brown over the cold winter and reddish brown during the hot summer (2) (4). The belly, buttocks and muzzle are white, and most Asiatic wild asses, with the exception of the Mongolian wild ass (5), have a broad black dorsal stripe, bordered with white (2) (4).
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Habitat

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The Asiatic wild ass inhabits flat steppe, semi-desert or desert and is always found within 30 km of a source of water (1) (5).
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Range

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Around 40,000 years ago, in the late Pleistocene era, Asian wild asses extended as far west as Germany (6). The current distribution of this species is vastly reduced (7). The Mongolian wild ass is found only in southern Mongolia and parts of northern China, but is by far the most abundant remaining subspecies. The sub-population in southern Mongolia alone accounts for almost 80 percent of the species' entire population (5) (6). All other populations number fewer than a hundred individuals. The Indian wild ass, also known as the khur, was once found throughout the arid part of north-west India (including part of present-day Pakistan), but it is now restricted to a small area of Gujarat, India. The onager is found in two very small sub-populations in Iran. The kulan is found in Kazakhstan and Turkmenistan, where it has undergone a dramatic decline. The kulan, onager and Indian wild ass all have very small and highly isolated sub-populations, and so are at great risk of extinction caused by chance events, such as the outbreak of disease or extreme climate events (1) (6).
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Status

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Classified as Endangered (EN) on the IUCN Red List (1). There are five recognised subspecies: the Mongolian wild ass (Equus hemionus hemionus) and the Indian wild ass or khur (E. h. khur) are listed under Appendix I of CITES; the Turkmen kulan (E. h. kulan) and the onager (E. h. onager) are listed on Appendix II of CITES (3); the Syrian wild ass (E. h. hemippus) is extinct.
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Threats

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The greatest threat facing the Asiatic wild ass is poaching for meat and hides, and in some areas for use in traditional medicine (5) (7). The extreme isolation of many of the subpopulations is, in itself, a threat, as genetic problems can result from inbreeding (7). Overgrazing by livestock reduces food availability, and herders also reduce the availability of water at springs. The cutting down of nutritious shrubs and bushes exacerbates the problem. Furthermore, a series of drought years could have devastating effects on this beleaguered species (6). Habitat fragmentation is a particular concern in Mongolia as result of the increasingly dense network of roads, railway lines and fences required to support mining activities (1) (5).
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Brief Summary

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The Asiatic wild ass (Equus hemionus) is a short-legged species of horse (family Equidae) native to the xeric mountain and desert steppes of Syria, Iran, Pakistan, India, Israel Central Asia and Mongolia. Similar in look to donkeys, they reach a slightly larger size, about 2.1 meters (6.9 feet) long and 200-260 kg (440-595 lbs).Their coat is red-brown in summer months and becomes yellower in winter, and they have a white-fringed black stripe down their back.Asiatic wild asses are primarily grazers, feeding preferentially on low shrubs and grasses including Stipa glareosa, Agropyron cristatum and Achnatherum Artemisia, grasses, Anabasis spp., Russian thistle (Salsola spp.), saxaul (Haloxylon ammodendron) and pea shrubs (Caragana spp.).When grasses are scarcer in drier seasons, however, their feeding strategy shifts to a browsing pattern and they will eat more broadly to include woody plants.

Equus hemionus includes at least four living subspecies (E. h. hemionus, the Mongolian wild ass; E. h. kulan, the Turkmenian kulan; E. h. onager, the Persian onager; and E. h. khur, the Indian wild ass).Another subspecies, the Syrian wild ass, E. h. hemippus, went extinct in 1927. Before molecular studies established it as its own species, the kiang, or Asiatic wild ass (now Equus kiang), was also considered a subspecies of E. hemionus.

Historically, this species ranged throughout Mongolia, much of China, the Middle East and Eastern Europe, however in the last 100 years its range has become significantly smaller and fragmented, with population numbers in decline.In the last 16 years its global population size has decreased 52%, to a current estimated population size of 8398 individuals.Threats to this species vary by local but include poaching for meat and hides, increase in human activities, competition for range land and water, fragmentation of grazing area and degradation of environment. The Asiatic wild ass is legally protected in Mongolia, Turkmenistan, Iran and India.All subspecies are included in CITES appendix I or II, and it has endangered status on the IUCN red list of threatened species. Researchers note that populations can crash to dangerously low levels in a very short time.Some reintroduction of species into native lands has been successful, but more research into basic behavior, ecology and disease control is called for.

(Moehlman, Shah and Feh 2008; Wikipedia 2014)

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Onager

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The onager (/ˈɒnəər/; Equus hemionus), also known as hemione or Asiatic wild ass,[3] is a species of the family Equidae (horse family) native to Asia. A member of the subgenus Asinus, the onager was described and given its binomial name by German zoologist Peter Simon Pallas in 1775. Five subspecies have been recognized, one of which is extinct.

The Asiatic wild ass is larger than the African wild ass at about 290 kg (640 lb) and 2.1 m (6.9 ft) (head-body length). They are reddish-brown or yellowish-brown in color and have broad dorsal stripe on the middle of the back. Unlike most horses and donkeys, onagers have never been domesticated. They are among the fastest mammals, as they can run as fast as 64 km/h (40 mph) to 70 km/h (43 mph). The onager is closely related to the African wild ass, as they both shared the same ancestor. The kiang, formerly considered a subspecies of Equus hemionus, diverged from the Asiatic wild ass and has been acknowledged as a distinct species.[4]

The onager formerly had a wider range from southwest and central to northern Asian countries, such as Israel, Saudi Arabia, Iraq, Jordan, Syria, Afghanistan, Russia, and Siberia. During early 20th century, the species lost most of its ranges in the Middle East and Eastern Asia. Today, onagers live in deserts and other arid regions of Iran, Pakistan, India, and Mongolia, including in Central Asian hot and cold deserts of Kazakhstan, Uzbekistan, Turkmenistan, and China.[1]

Other than deserts, it lives in grasslands, plains, steppes, and savannahs. Like many other large grazing animals, the onager's range has contracted greatly under the pressures of poaching and habitat loss.[3] Previously listed as Endangered, onagers have been classified as Near Threatened by IUCN in 2015.[2] Of the five subspecies, one is extinct, two are endangered, and two are near threatened (their status in China is not well known).[3] Persian onagers are currently being reintroduced in the Middle East as replacements for the extinct Syrian wild ass in the Arabian Peninsula, Israel and Jordan.

Etymology

The specific name is Ancient Greek ἡμίονος (hēmíonos), from ἡμι- (hēmi-), half, and ὄνος (ónos), donkey; thus, half-donkey or mule. The term onager comes from the ancient Greek ὄναγρος, again from ὄνος ('onos), donkey, and ἄγριος ('agrios), wild.

The species was commonly known as Asian wild ass, in which case the term onager was reserved for the E. h. onager subspecies,[3] more specifically known as the Persian onager. Until this day, the species share the same name, onager.

Taxonomy and evolution

The onager is a member of the subgenus Asinus, belonging to the genus Equus and is classified under the family Equidae. The species was described and given its binomial name Equus hemionus by German zoologist Peter Simon Pallas in 1775.

The Asiatic wild ass, among Old World equids, existed for more than 4 million years. The oldest divergence of Equus was the onager followed by the zebras and onwards.[5] A new species called the kiang (E. kiang), a Tibetan relative, was previously considered to be a subspecies of the onager as E. hemionus kiang, but recent molecular studies indicate it to be a distinct species, having diverged from the closest relative of the Mongolian wild ass's ancestor less than 500,000 years ago.[4]

   

Syrian wild ass (E. h. hemippus)

     

Persian onager (E. h. onager)

       

Indian wild ass (E. h. khur)

   

Turkmenian kulan (E. h. kulan)

     

Mongolian wild ass (E. h. hemionus)

       

Subspecies

Widely five recognized subspecies of the onager include:[3]

A sixth possible subspecies, the Gobi khulan (E. h. luteus,[2] also called the chigetai[6] or dziggetai) has been proposed, but may be synonymous with E. h. hemionus.

Debates over the taxonomic identity of the onager occurred until 1980. As of today, four living subspecies and one extinct subspecies of the Asiatic wild ass have been recognized. The Persian onager was formerly known as Equus onager, as it was thought to be a distinct species.

Characteristics

 src=
A Turkmenian kulan
 src=
The skeleton

Onagers are the most horse-like of wild asses. They are short-legged compared to horses, and their coloring varies depending on the season. They are generally reddish-brown in color during the summer, becoming yellowish-brown or grayish-brown in the winter. They have a black stripe bordered in white that extends down the middle of the back. The belly, the rump, and the muzzle are white in most onagers, except for the Mongolian wild ass that has a broad black dorsal stripe bordered with white.

Onagers are larger than donkeys at about 200 to 290 kg (440 to 640 lb) in size and 2.1 to 2.5 m (6.9 to 8.2 ft) in head-body length. Male onagers are usually larger than females.

Evolution

 src=
Skull of a giant extinct horse, Equus eisenmannae

The genus Equus, which includes all extant equines, is believed to have evolved from Dinohippus via the intermediate form Plesippus. One of the oldest species is Equus simplicidens, described as zebra-like with a donkey-shaped head. The oldest fossil to date is about 3.5 million years old from Idaho, USA. The genus appears to have spread quickly into the Old World, with the similarly aged Equus livenzovensis documented from western Europe and Russia.[7]

Molecular phylogenies indicate the most recent common ancestor of all modern equids (members of the genus Equus) lived around 5.6 (3.9–7.8) million years ago (Mya). Direct paleogenomic sequencing of a 700,000-year-old middle Pleistocene horse metapodial bone from Canada implies a more recent 4.07 Mya for the most recent common ancestor within the range of 4.0 to 4.5 Mya.[8] The oldest divergencies are the Asian hemiones (subgenus E. (Asinus), including the kulan, onager, and kiang), followed by the African zebras (subgenera E. (Dolichohippus), and E. (Hippotigris)). All other modern forms including the domesticated horse (and many fossil Pliocene and Pleistocene forms) belong to the subgenus E. (Equus) which diverged about 4.8 (3.2–6.5) Mya.[5]

Distribution and habitat

 src=
An Indian wild ass in Little Rann of Kutch, Gujarat

The onagers' favored habitats consist of desert plains, semideserts, oases, arid grasslands, savannahs, shrublands, steppes, mountainous steppes, and mountain ranges. The Turkmenian kulan and Mongolian wild asses are known to live in hot and colder deserts. The IUCN estimates about 28,000 mature individuals in total remain in the wild.[2]

During the late Pleistocene era around 40,000 years ago, the Asiatic wild ass ranged widely across Europe and in southwestern to northeastern Asia. The onager has been regionally extinct in Israel, Saudi Arabia, Iraq, Jordan, Syria, and southern regions of Siberia.

 src=
Onagers at Wadi Lotz, Negev Mountains, Israel

The Mongolian wild ass lives in deserts, mountains, and grasslands of Mongolia and Inner Mongolian region of northern China. A few live in northern Xinjiang region of northwestern China, most of which live mainly in Kalamaili Nature Reserve. It is the most common subspecies, but its populations have drastically decreased to a few thousand due to years of poaching and habitat loss in East Asia. The Gobi Desert is the onager's main stronghold. It is regionally extinct in eastern Kazakhstan, southern Siberia, and the Manchurian region of China.

The Indian wild ass was once found throughout the arid parts and desert steppes of northwest India and Pakistan, but about 4,500 of them are found in a few very hot wildlife sanctuaries of Gujarat. The Persian onager is found in two subpopulations in southern and northern Iran. The larger population is found at Khar Turan National Park. However, it is extinct in the wild of Afghanistan. The Turkmenian kulan used to be widespread in central to north Asia. However, it is now found in Turkmenistan and has been reintroduced in southern Kazakhstan and Uzbekistan.

Biology and behavior

Asiatic wild asses are mostly active at dawn and dusk, even during the intense heat.

Social structure

 src=
A group of onagers
 src=
A group of khurs

Like most equids, onagers are social animals. Stallions are either solitary or live in groups of two or three. The males have been observed holding harems of females, but in other studies, the dominant stallions defend territories that attract females. Differences in behaviour and social structure likely are the result of changes in climate, vegetation cover, predation, and hunting.

The social behavior of the Asian wild ass can be very different, depending on different habitats, ranges, and even threats by predators and humans. In Mongolia and Central Asia (E. h. hemionus and ''E. h. kulan), a stove onager stallion can adopt harem-type social groups with several mares and foals in large home areas in the southwest and territory-based social groups in the south and southeast. Also, annual large hikes occur 4.5 km2 (1.7 sq mi) to 40 km2 (15 sq mi), where hiking in summer is more limited than in the winter. Partially, onagers also form large group associations of 450 to 1,200 individuals, but this usually only takes place on locations with food or water sources. Since dissolving these major units within one day again, no overarching hierarchy next to the ranking of the individual herds seems to exist. Also, young male onagers frequently form "bachelor groups" during the winter. Such a lifestyle is also seen in the wild horse, the plains zebras (E. quagga) and mountain zebras (E. zebra).

Southern populations of onagers in the Middle East and South Asia tend to have a purely territorial life, where areas partly overlap. Dominant stallions have home ranges of 9 km2 (3.5 sq mi), but they can also be significantly larger. These territories include food and rest stops and permanent or periodic water sources. The waters are usually at the edge of a coalfield and not in the center. Mares with foals sometimes find themselves in small groups, in areas up to 20 km2 (7.7 sq mi), which overlap with those of the other groups and dominant stallions. Such features are seen in Grévy's zebras (E. grevyi) and the African wild asses.

Reproduction

The Asian wild ass is sexually mature at two years old, and the first mating usually takes place at three to four years old.

Breeding is seasonal, and the gestation period of onagers is 11 months; the birth lasts a little more than 10 minutes. Mating and births occur from April to September, with an accumulation from June to July. The mating season in India is in the rainy season. The foal can stand and starts to nurse within 15 to 20 minutes. Females with young tend to form groups of up to five females. During rearing, a foal and dam remain close, but other animals and her own older offspring are displaced by the dam. Occasionally, stallions in territorial wild populations expel the young to mate with the mare again. Wild Asian wild asses reach an age of 14 years, but in captivity, they can live up to 26 years.

Diet

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Indian wild ass herd feeding on grasses

Like all equids, onagers are herbivorous mammals. They eat grasses, herbs, leaves, fruits, and saline vegetation when available, but browse on shrubs and trees in drier habitats. They have also been seen feeding on seed pods such as Prosopis and breaking up woody vegetation with their hooves to get at more succulent herbs growing at the base of woody plants.

During the winter, onagers also eat snow as a substitute for water. When natural water sources are unavailable, the onager digs holes in dry riverbeds to access subsurface water. The water holes dug by the onagers are often subsequently visited by domestic livestock, as well as other wild animals. Water is also found in the plants on which the onagers feed.

During spring and summer in Mongolia, the succulent plants of the Zygophyllaceae form an important component of the diet of the Mongolian wild ass.

Predation

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An Asiatic lion attacking an onager (Roman, c. AD 150)

The onager is preyed upon by apex predators such as Persian leopard and striped hyenas. A few cases of onager deaths due to predation by leopards were recorded in Iran. Though leopards do not usually feed on equids as in Africa, this may be because Persian leopards are larger and strong enough to prey on Asiatic wild asses.[9][10]

In the Middle East and the Indian subcontinent, Asiatic lions and tigers were the biggest predators of onagers. They were also formerly preyed upon by Asiatic wild dog, Asiatic cheetahs, and possibly bears, though they may have mostly preyed only on onager foals. In India, mugger crocodiles can be great threats to onagers during migratory river crossings.

Currently, the biggest predator for onagers are gray wolves. About 23% of prey proportion of gray wolves were on the Asian wild ass. However, like most equids, they are known to have antipredator protection. Groups of stallions cooperate and try to chase off predators. If threatened, onagers defend themselves and violently kick at the incoming predator.

Threats

The greatest threat facing the onager is poaching for meat and hides, and in some areas for use in traditional medicine. It is the one of highest threats for the Mongolian wild ass. The extreme isolation of many subpopulations also threatens the species, as genetic problems can result from inbreeding. Overgrazing by livestock reduces food availability, and herders also reduce the availability of water at springs. The cutting down of nutritious shrubs and bushes exacerbates the problem. Furthermore, a series of drought years could have devastating effects on this beleaguered species.

Habitat loss and fragmentation are also major threats to the onager, a particular concern in Mongolia as a result of the increasingly dense network of roads, railway lines, and fences required to support mining activities.

The Asiatic wild ass is vulnerable to diseases, as well. A disease known as the "South African horse sickness" caused a major decline to the Indian wild ass population in the 1960s. However, the subspecies is no longer under threat to such disease and is continuously increasing in number.

Conservation

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A Persian onager in Augsburg Zoo

Various breeding programs have been started for the onager subspecies in captivity and in the wild, which increases their numbers to save the endangered species. The species is legally protected in many of the countries in which it occurs. The priority for future conservation measures is to ensure the protection of this species in particularly vulnerable parts of its range, to encourage the involvement of local people in the conservation of the onager, and to conduct further research into the behavior, ecology, and taxonomy of the species.

Two onager subspecies, the Persian onager and the Turkmenian kulan are being reintroduced to their former ranges, including in other regions the Syrian wild ass used to occur in the Middle East. The two subspecies have been reintroduced to the wild of Israel since 1982, and had been breeding hybrids there,[11] whilst the Persian onager alone has been reintroduced to Jordan and the deserts of Saudi Arabia.

Interaction with human beings

Onagers are notoriously untamable. Equids were used in ancient Sumer to pull wagons c. 2600 BC, and then chariots on the Standard of Ur, c. 2550 BC. Clutton-Brock (1992) suggests that these were donkeys rather than onagers on the basis of a "shoulder stripe".[12] However, close examination of the animals (equids, sheep and cattle) on both sides of the piece indicate that what appears to be a stripe may well be a harness, a trapping, or a joint in the inlay.[13][14]

In literature

In La Peau de Chagrin by Honoré de Balzac, the onager is identified as the animal from which comes the ass's skin or shagreen of the title.

References

  1. ^ a b Grubb, P. (2005). "Order Perissodactyla". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 632. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. ^ a b c d Kaczensky, P.; Lkhagvasuren, B.; Pereladova, O.; Hemami, M. & Bouskila, A. (2015). "Equus hemionus". IUCN Red List of Threatened Species. IUCN. 2015: e.T7951A45171204. doi:10.2305/IUCN.UK.2015-4.RLTS.T7951A45171204.en.
  3. ^ a b c d e "Asiatic Wild Ass Equus hemionus". IUCN.org. Gland, Switzerland: IUCN/SSC Equid Specialist Group. Archived from the original on 20 December 2012.
  4. ^ a b Ryder, O.A. & Chemnick, L.G. (1990). "Chromosomal and molecular evolution in Asiatic wild asses". Genetica. 83 (1): 67–72. doi:10.1007/BF00774690. PMID 2090563.
  5. ^ a b Weinstock, J.; et al. (2005). "Evolution, systematics, and phylogeography of Pleistocene horses in the New World: a molecular perspective". PLoS Biology. 3 (8): e241. doi:10.1371/journal.pbio.0030241. PMC 1159165. PMID 15974804. Retrieved 19 December 2008.
  6. ^ Ian Lauder Mason (2002). Porter, Valerie (ed.). Mason's World Dictionary of Livestock Breeds, Types, and Varieties (5th ed.). Wallingford: CABI. ISBN 0-85199-430-X.
  7. ^ Azzaroli, A. (1992). "Ascent and decline of monodactyl equids: a case for prehistoric overkill" (PDF). Ann. Zool. Finnici. 28: 151–163.
  8. ^ Orlando, L.; Ginolhac, A.; Zhang, G.; Froese, D.; Albrechtsen, A.; Stiller, M.; Schubert, M.; Cappellini, E.; Petersen, B.; et al. (4 July 2013). "Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse". Nature. 499 (7456): 74–8. doi:10.1038/nature12323. PMID 23803765.
  9. ^ Sanei, A., Zakaria, M., Hermidas, S. (2011). "Prey composition in the Persian leopard distribution range in Iran". Asia Life Sciences Supplement 7 (1): 19−30.CS1 maint: multiple names: authors list (link)
  10. ^ Persian Leopard Newsletter No.4 (PDF). Wildlife.ir. 2010. Retrieved 3 July 2016.
  11. ^ Saltz, D. (1995). "Population dynamics of a reintroduced Asiatic wild ass (Equus Hemionus) herd". Ecological Applications. 5 (2): 327–335. doi:10.2307/1942025.
  12. ^ Clutton-Brock, Juliet (1992). Horse Power: A History of the Horse and the Donkey in Human Societies. Boston, Massachusetts, US: Harvard University Press. ISBN 978-0-674-40646-9.
  13. ^ Heimpel, Wolfgang (1968). Tierbilder in der Sumerische Literatur. Italy: Studia Pohl 2.
  14. ^ Maekawa, K. (1979). "The Ass and the Onager in Sumer in the Late Third Millennium B.C.". Acta Sumerologica. Hiroshima. I: 35–62.
  • Duncan, P., ed. (1992). Zebras, Asses, and Horses: An Action Plan for the Conservation of Wild Equids. Gland, Switzerland: IUCN/SSC Equid Specialist Group. ISBN 9782831700526. OCLC 468402451.

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Onager: Brief Summary

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The onager (/ˈɒnədʒər/; Equus hemionus), also known as hemione or Asiatic wild ass, is a species of the family Equidae (horse family) native to Asia. A member of the subgenus Asinus, the onager was described and given its binomial name by German zoologist Peter Simon Pallas in 1775. Five subspecies have been recognized, one of which is extinct.

The Asiatic wild ass is larger than the African wild ass at about 290 kg (640 lb) and 2.1 m (6.9 ft) (head-body length). They are reddish-brown or yellowish-brown in color and have broad dorsal stripe on the middle of the back. Unlike most horses and donkeys, onagers have never been domesticated. They are among the fastest mammals, as they can run as fast as 64 km/h (40 mph) to 70 km/h (43 mph). The onager is closely related to the African wild ass, as they both shared the same ancestor. The kiang, formerly considered a subspecies of Equus hemionus, diverged from the Asiatic wild ass and has been acknowledged as a distinct species.

The onager formerly had a wider range from southwest and central to northern Asian countries, such as Israel, Saudi Arabia, Iraq, Jordan, Syria, Afghanistan, Russia, and Siberia. During early 20th century, the species lost most of its ranges in the Middle East and Eastern Asia. Today, onagers live in deserts and other arid regions of Iran, Pakistan, India, and Mongolia, including in Central Asian hot and cold deserts of Kazakhstan, Uzbekistan, Turkmenistan, and China.

Other than deserts, it lives in grasslands, plains, steppes, and savannahs. Like many other large grazing animals, the onager's range has contracted greatly under the pressures of poaching and habitat loss. Previously listed as Endangered, onagers have been classified as Near Threatened by IUCN in 2015. Of the five subspecies, one is extinct, two are endangered, and two are near threatened (their status in China is not well known). Persian onagers are currently being reintroduced in the Middle East as replacements for the extinct Syrian wild ass in the Arabian Peninsula, Israel and Jordan.

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