Yak (Sp), Yak (G), Yak, Vache de Tartarie (F). Some authorities distinguish between the domestic (including feral) yak as Bos grunniens and the wild yak as B. mutus, while others, including ourselves, do not differentiate. As it was the domestic form that was first described for science, the name grunniens Linnaeus, 1766 takes precedence.
DESCRIPTION A wild male yak in its Tibetan homeland can measure up to 10-1/2 feet (3.2 m) in length, stand up to six feet (1.8 m) at the shoulder, and weigh up to 2,200 pounds (1,000 kg). It has a massive build with humped shoulders, short legs and large hoofs. A fringe of long hairs extends around the lower part of the body, almost touching the ground, and the tail has a mass of long hairs. The color is a uniform blackish-brown except for some white on the muzzle. Both sexes grow long, wide-spreading horns. Females are only one-third the size of males and have much slimmer horns.
DISTRIBUTION Private ranches in various parts of the United States.
REMARKS Yaks have been domesticated for about 3,000 years and are found in association with people throughout the highlands of central Asia. They are used for riding, as pack animals and for their meat, milk and wool. Strong, docile and sure-footed, they are the most useful domestic animals at higher elevations. It is estimated there are as many as 12 million domestic and feral yaks, but probably only a few hundred wild yaks (Alexander, 1987), which are listed as endangered. Like other Bos species, yaks are classified as oxen or cattle. They have the same number of chromosomes as domestic cattle and will interbreed with them, producing fertile female and (normally) sterile male offspring. Domestic and feral yaks are smaller than wild yaks, with smaller horns and coloration that can vary from black to brown to reddish, or even mottled. Yaks on game ranches in North America are of this type.
HYBRIDIZATION The yak is either known or believed to crossbreed, or to be the result of hybridization, when in a game ranch environment. Please see full statement on hybridization of ranched animals.