a small, gregarious, graceful antelope-like mammal of the family Bovidae (bovid) (order Artiodactyla (artiodactyl)) that lives on the high alpine steppes of the Tibetan Plateau (Tibet, Plateau of). Males carry thin, long horns that curve slightly forward; females are hornless. On each side of the blunt muzzle are two small bulges that contain air sacs used in vocalization.

Adult males stand about 83 cm (33 inches) at the shoulder and weigh about 40 kg (88 pounds); females stand about 74 cm (29 inches) at the shoulder and weigh about 25 kg (55 pounds). The stocky body stands on long, slim legs indicative of swift running and irregular, long-distance travels between seasonal ranges. The chiru has a modest rump patch, a short tail, and fairly small ears.

During the breeding season in December, the male's face and the fronts of its legs, which are those parts most visible to a challenging rival, are black and sharply contrasted by white fur, as well as by the yellowish gray-brown colour of the body. The winter coat is dense and woolly. This nuptial pelage is typical only of adult males over four years of age. Females lack the sharply contrasting coat patterns.

Sexes segregate into different herds in summer and travel apart, with females going on longer migrations of up to some 300 km (200 miles). During the rutting season large herds form in which males defend and herd harems. Single fawns are born in late June and early July. The fawns are suckled with a rich milk high in fat, and they grow rapidly. Adult size is reached in less than two years from birth.

Chiru feed on low alpine grasses, forbs, and shrubs. They may have to excavate these from below snow. Chiru are preyed upon by wolves (wolf), snow leopards (snow leopard), and lynxes (lynx). Many chiru starve to death after sudden high snowfalls and die from very low temperatures. In both summer and winter, there is high mortality among the young and among males as compared with females. The maximum age reached by adults appears to be under 10 years.

The chiru is the only genus of large mammals (mammal) endemic to the Tibetan Plateau (Tibet, Plateau of). Despite its antelope-like appearance, the chiru is not related to antelopes or to gazelles (gazelle) but represents the last remnant of a group of ruminants (ruminant) that split off from the sheep, goat, and goat antelope lineages late in the Tertiary Period. It was extremely abundant on the Tibetan Plateau and surrounding high-elevation alpine steppes, but now it survives only in the extreme climate of the Tibetan Plateau.

Large numbers of chiru are poached for their fine wool, which is smuggled into India and then made into scarves and shawls that fetch exorbitant prices in affluent countries. Despite the enactment of protective measures, the future of this species is uncertain, as once-abundant herds have shrunk severely and rapidly.