Kiang Explained

The kiang (Equus kiang) is the largest of the Asinus subgenus. It is native to the Tibetan Plateau in Ladakh India, northern Pakistan, Tajikistan, China and northern Nepal. It inhabits montane grasslands and shrublands. Other common names for this species include Tibetan wild ass, khyang and gorkhar.

Characteristics

The kiang is the largest of the wild asses, with an average height at the withers of 140cm (60inches). They range from 132cmto142cmcm (52inchesto56inchescm) high at the withers, with a body 182cmto214cmcm (72inchesto84inchescm) long, and a tail of 32cmto45cmcm (13inchesto18inchescm). Kiangs have only slight sexual dimorphism, with the males weighing from 350kgto400kgkg (770lbto900lbkg), while females weigh 250kgto300kgkg (550lbto700lbkg). They have a large head, with a blunt muzzle and a convex nose. The mane is upright and relatively short. The coat is a rich chestnut colour, darker brown in winter and a sleek reddish brown in late summer, when the animal moults its woolly fur. The summer coat is 1.5cm (00.6inches) long and the winter coat is double that length. The legs, underparts, end of the muzzle, and the inside of the ears are all white. A broad, dark chocolate-coloured dorsal stripe extends from the mane to the end of the tail, which ends in a tuft of blackish brown hairs.[1]

Evolution

See also: Evolution of the horse. 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 ~3.5 million years old from Idaho, US. The genus appears to have spread quickly into the Old World, with the similarly aged Equus livenzovensis documented from western Europe and Russia.[2]

Molecular phylogenies indicate the most recent common ancestor of all modern equids (members of the genus Equus) lived ~5.6 (3.9–7.8) mya. Direct paleogenomic sequencing of a 700,000-year-old middle Pleistocene horse metapodial bone from Canada implies a more recent 4.07 Myr before present date for the most recent common ancestor (MRCA) within the range of 4.0 to 4.5 Myr BP.[3] 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 ~4.8 (3.2–6.5) million years ago.[4]

Taxonomy

The kiang is closely related to the onager (Equus hemionus), and in some classifications it is considered a subspecies, E. hemionus kiang. Molecular studies, however, indicate that it is a distinct species.[5] An even closer relative, however, may be the extinct Equus conversidens of Pleistocene America,[6] to which it bears a number of striking similarities; however, such a relationship would require kiangs to have crossed Beringia during the Ice Age, for which little evidence exists. Kiangs can crossbreed with onagers, horses, donkeys, and Burchell's zebras in captivity, although, like mules, the resulting offspring are sterile. Kiangs have never been domesticated.[1]

Three kiang subspecies are currently recognised:[1]

The eastern kiang is the largest subspecies; the southern kiang is the smallest. The western kiang is slightly smaller than the eastern and also has a darker coat. However, no genetic information confirms the validity of the three subspecies, which may simply represent a cline, with gradual variation between the three forms.

Distribution and habitat

The kiang is distributed from the Kunlun Mountains in the north, the Tibetan Plateau to the Himalayas in the south. It occurs mostly in China, but about 2,500–3,000 kiangs are thought to inhabit the Ladakh, Himachal Pradesh, and Uttarakhand regions of India, and smaller numbers along the northern frontier of Nepal.[7]

Kiang herds inhabit alpine meadows and steppe country between elevation. They prefer relatively flat plateaus, wide valleys, and low hills, dominated by grasses, sedges, and smaller amounts of other low-lying vegetation. This open terrain, in addition to supplying them with suitable forage absent in the more arid regions of central Asia, may make it easier for them to detect, and flee from, predators.[8]

Behavior and ecology

The kiang is a herbivore, feeding on grasses and sedges, especially Stipa, but also on other plants such as bog sedges, true sedges, and meadow grasses. When little grass is available, such as during winter or in the more arid margins of their native habitat, kiangs have been observed eating shrubs, herbs, and even Oxytropis roots dug from the ground. Although they do sometimes drink from waterholes, such sources of water are rare on the Tibetan Plateau, and they likely obtain most of their water from the plants they eat, or possibly from snow in winter.[1]

Kiangs sometimes gather in large herds, which may number several hundred individuals. However, these herds are not permanent groupings, but temporary aggregations, consisting either of young males only, or of mothers and their foals. Older males are typically solitary, defending a territory of about from rivals, and dominating any local groups of females. Territorial males sometimes become aggressive towards intruders, kicking and biting at them, but more commonly chase them away after a threat display that involves flattening the ears and braying.[1]

Reproduction

Kiangs mate between late July and late August, when older males tend reproductive females by trotting around them, and then chasing them prior to mating. The length of gestation has been variously reported as seven to 12 months, and results in the birth of a single foal. Females are able to breed again almost immediately after birth, although births every other year are more common. Foals weigh up to at birth, and are able to walk within a few hours. The age of sexual maturity is unknown, although probably around three or four years, as it is in the closely related onager. Kiang live for up to 20 years in the wild.[1]

In culture

Natural historian Chris Lavers points to travellers' tales of the kiang as one source of inspiration for the unicorn, first described in Indika by the Ancient Greek physician Ctesias.[9]

Ekai Kawaguchi, a Japanese monk who traveled in Tibet from July, 1900 to June 1902, reported:

Thubten Jigme Norbu, the elder brother of Tenzin Gyatso the 14th Dalai Lama, reporting on his trip from Kumbum Monastery in Amdo to Lhasa in 1950, wrote:

Further reading

Notes and References

  1. St-Louis, A. . Côté, S. . 2009 . Equus kiang (Perissodactyla: Equidae) . Mammalian Species . 835 . 1–11 . 10.1644/835.1. free .
  2. Azzaroli . A. . 1992 . Ascent and decline of monodactyl equids: a case for prehistoric overkill . Ann. Zool. Finnici . 28 . 151–163 .
  3. Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse . Orlando. L.. Ginolhac. A.. Zhang. G.. Froese. D.. Albrechtsen. A.. Stiller. M.. Schubert. M.. Cappellini. E.. Petersen. B.. Nature. 4 July 2013 . 10.1038/nature12323 . 23803765 . 499 . 7456 . 74–8. 2013Natur.499...74O. 4318227. etal.
  4. Weinstock . J. . 2005 . Evolution, systematics, and phylogeography of Pleistocene horses in the New World: a molecular perspective . . 3 . 8 . e241 . 10.1371/journal.pbio.0030241 . 15974804 . 1159165 . etal . free .
  5. Ryder, O.A. . Chemnick, L.G. . 1990 . Chromosomal and molecular evolution in Asiatic wild asses . Genetica . 83 . 1 . 67–72 . 10.1007/BF00774690 . 2090563. 12351710.
  6. Bennett, D.K. . 1980 . Stripes do not a zebra make, part I: a cladistic analysis of Equus . Systematic Zoology . 29 . 3 . 272–287 . 10.2307/2412662. 2412662.
  7. Book: Shah, N.. Moehlman, P.D. . 2002 . Equids: zebras, asses and horses. Status survey and conservation action plan . IUCN . Gland, Switzerland . 72–81. 2011-05-14. 2018-12-31 . https://web.archive.org/web/20181231144037/http://data.iucn.org/themes/ssc/sgs/equid/EAP.html. dead.
  8. Harris, R.B. . Miller, D.J. . 1995 . Overlap in summer habitats and diets of Tibetan Plateau ungulates . Mammalia . 59 . 2 . 197–212 . 10.1515/mamm.1995.59.2.197 . 84659876.
  9. Book: Lavers, C. . 2009 . The Natural History of Unicorns . HarperCollins Publishers . New York . 978-0-06-087414-8.