Note:  Do not rely on this information. It is very old.

Yak

Yak (Bos grunniens), a Tibetan ox, domesticated by the natives as a beast of burden. The wild race, generally brownish-black, is found near the snow line, coming down in winter to feed on the grass in the wooded valleys. The domesticated race has white mixed with the darker colour. The size is somewhat less than that of the ox, and a long fringe of hair covers the shoulders, flanks, thighs, and tail.