A reddish-brown Asian relative of our domestic donkey with several subspecies (such as the kiang and onager) which are endangered.

Subspecies
4 subspecies, although two of them (the kiang and onager) are sometimes classified as separate species. The Syrian subspecies is now extinct.

Life span
25-30 years (up to 50 in captivity).

Statistics
210cm long with a 49cm tail.

Physical description
A larger animal than the African ass, with a reddish brown coat (becoming paler in the winter), a white belly and a prominent dark stripe down the back. It has a dark, upright mane, dark tips to the ears and a dark tassle on the tail, and has broad, round hooves.

Distribution
Syria, Iran, Northern India and Tibet.

Habitat
Rocky deserts.

Diet
Grass and other vegetation.

Behaviour
Wild asses are mostly solitary. Males defend large territories and mate with females which wander through them. They do form loose herds too - often groups of territory-less males or females. This is because the food in their dry habitats is so widely spaced out that there isn't enough to go round a whole herd in one place. They communicate through scent and visual signals as well as calls.

Reproduction
A single foal is born after a gestation period of 12 months at any time of the year. The foals are well developed, and can walk within half an hour of birth. They are weaned at about 5 months, and reach sexual maturity between 1 and 2 years of age.

Conservation status
As a whole, the species is listed as 'Data Deficient' although some subspecies are listed as Endangered. Competition with livestock when their habitats are settled is a problem.

History
Modern horses are all closely related. They all have only one functional toe (with the nail formed into a hoof) on each foot. Their ancestors back in the Eocene, though, like Propalaeotherium, had three on the front feet and four on the back. They also had pads like a cat or dog. They were small animals, living in the vast expanses of Eocene forest. As plains opened up, fast-running animals evolved. Some horses adapted to this lifestyle and grew long, running legs.