Przewalski's horse

Przewalski's Horse
Conservation status
Endangered
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Perissodactyla
Family:	Equidae
Genus:	Equus
Subgenus:	Equus
Species:	E. ferus
Subspecies:	E. f. przewalskii
Trinomial name
Equus ferus przewalskii (Poliakov, 1881)

Przewalski's Horse (Equus ferus przewalskii or Equus caballus przewalskii, classification is debated), pronounced in English as /ʃe'væl.skiː/ or [prʑɛ'væl.ski] with Polish pronunciation, also known as the Mongolian Wild Horse, or Takhi, is the closest living relative of the Domestic Horse. Poliakov, who concluded that the animal was a wild horse species, gave it the official name Equus przewalskii (Poliakov 1881). However, authorities differ about the correct classification. Some hold it is a separate species, the last remnant of the wild horse Equus ferus, others hold it is a subspecies of Equus caballus. The question will only be answered with finality if or when the common ancestor from which domestic and Przewalski's horses diverged is determined. Although the Przewalski's horse has 66 chromosomes, compared to 64 in a domestic horse, the Przewalski's horse and the domestic horse are the only equids that cross-breed and produce fertile offspring, possessing 65 chromosomes.

As of a census taken in 2005, the world population of these horses was about 1,500, all descended from 31 horses that were in captivity in 1945, mostly descended from approximately 15 captured around 1900. A cooperative venture between the Zoological Society of London and Mongolian Scientists has resulted in successful reintroduction of these horses from zoos into their natural habitat in Mongolia, and as of 2005 there is a free-ranging population of 248 animals in the wild.

History

The horse is named after Russian General Nikolai Przhevalsky (Przewalski) (1839–1888) who was also an explorer and naturalist (the "Przewalski" spelling is actually Polish). He described the horse in 1881, after having gone on an expedition to find it, based on rumours of its existence. Many horses were captured around 1900 by Carl Hagenbeck and placed in zoos. As noted above, about twelve to fifteen reproduced and formed today's population.

The population declined in the 20th century due to a combination of factors, with the wild population in Mongolia dying out in the 1960s. The last herd was sighted in 1967 and the last individual horse in 1969. Expeditions after this failed to locate any horses, and the species was designated "extinct in the wild" for over 30 years.

In 1977, the "Foundation for the Preservation and Protection of the Przewalski Horse" was founded, which started a program of exchange between captive populations in zoos throughout the world to reduce inbreeding, and later starting a breeding program of its own. In 1992, sixteen horses were released into the wild in Mongolia, followed by additional animals later on. These reintroduced horses successfully reproduced, and the status of the animal was changed from "extinct in the wild" to "endangered" in 2005.

The area to which they were reintroduced became Hustai National Park in 1998.

Other Reserves for the Przewalski's Horse

The world's largest captive breeding program for Przewalski's horses is at the Askania Nova preserve in Ukraine. Several dozen Przewalski's horses were also released in the area evacuated after the Chernobyl accident, which now serves as a deserted de facto natural preserve. Wormwood Forest: A Natural History of Chernobyl devotes an entire chapter to the Przewalski's horses of Chernobyl.

A small population of Przewalski's horses exists in Monarto Zoological Park in Murray Bridge, South Australia

Three of these horses now graze in a 49,000 square meter paddock in the Clocaenog Forest in North Wales, UK, on the site of a former Neolithic or Iron Age settlement. They were introduced there in 2004. The Forestry Commission hopes they will help recreate scenes from the Iron Age when these horses roamed Britain freely.

Appearance and behaviour

Main article: horse behavior

Przewalski's Horses

Przewalski's Horse is stockily built in comparison to domesticated horses, with shorter legs. Typical height is about 13 hands, length is about 2.1 m with a 90 cm tail. They weigh around 350 kg. The coat is similar to Dun coloration in domestic horses. It varies from dark brown around the mane (which stands erect) to pale brown on the flanks and yellowish-white on the belly. The legs of the Przewalski's Horse are often faintly striped.

In the wild, Przewalski's Horses live in social groups consisting of a dominant male, several mares, and their offspring. Each group has a well-defined home range; within the range, the herd travels between three and six miles a day, spending time grazing, drinking, using salt licks, dozing, and taking mud baths. At night, the herd clusters and sleeps for about four hours.

Fillies and colts both leave their natal groups as they reach sexual maturity, usually driven out by the dominant stallion. Fillies generally look for a new herd to join, after which they will begin to reproduce. Colts usually find one another and spend a year or two in small bachelor herds. At around age 5, a stallion will leave the bachelor herd and attempt to take over an existing herd by challenging the dominant stallion, or by "stealing" one or more mares from another stallion's harem, or by gathering unattached fillies.

Interesting Facts

The unique characteristics of the horse itself made it particularly valuable to hunters. The horse would eat grass, and the chlorophyll would release from the chloroplasts inside their mouths, creating a thick green mucus stored in the back of their throats. Hunters would kill the horses for the mucus, as it was thought to cure a virus circulating at the time of the rapid declination of the species.

References

• www.takhi.org [2]
• Equid Specialist Group 1996. Equus ferus. In: IUCN 2004. 2004 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 24 December 2005. [3]
• Equid Specialist Group 1996. Equus ferus ssp. przewalskii. In: IUCN 2004. 2004 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 16 February 2006. [4]
• Forestry Commission. 2004. FC Wales turns clock back thousands of years with 'wild' solution to looking after ancient forest site. News release, No: 7001, 16 September 2004. [5]
• International Commission on Zoological Nomenclature. 2003. Opinion 2027 (Case 3010). Usage of 17 specific names based on wild species which are pre-dated by or contemporary with those based on domestic animals (Lepidoptera, Osteichthyes, Mammalia): conserved. Bull.Zool.Nomencl., 60:81-84. [6].
• Ishida, N., Oyunsuren, T., Mashima, S., Mukoyama, H., and Saitou, N. J Mol Evol. 1995. Mitochondrial DNA sequences of various species of the genus Equus with special reference to the phylogenetic relationship between Przewalskii's wild horse and domestic horse. Journal of molecular evolution; 41(2): 180–188. [7]
• Jansen, T., Forster, P., Levine, M.A., Oelke, H., Hurles, M., Renfrew, C., Weber, J., and Olek, K. 2002. Mitochondrial DNA and the origins of the domestic horse. Proceedings of the National Academy of Sciences of the United States of America; 99(16): 10905–10910. [8]
• Wakefield, S., Knowles, J., Zimmermann, W. and Van Dierendonck, M. 2002. Status and action plan for the Przewalski's Horse (Equus ferus przewalski). In: P.D. Moehlman (ed.) Equids: Zebras, Asses and Horses. Status Survey and Conservation Action Plan, pp. 82-92. IUCN/SSC Equid Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. [9]
• NYT/AP story: [10] (population figures)

See also

• Mongolian domestic horse
• Wild horse
• Tarpan
• Horse article, wild species subsection

External links

• ARKive - images and movies of the Przewalski's horse (Equus ferus przewalskii)
• Details of the re-introduction program for Przewalski's horse.
• Breeding an reintroduction program of the Przewalski's horse at Zoo Hellabrunn Munich
• Details of the history and captive breeding program for Przewalski's Horse.