Despite recent interest in domesticated animal in general and bovines in particular, there has been little systematic study of yak. Nevertheless, enough is known to warrant a closer consideration of the role these cattle play in the culture, diet, and ecology of the several peoples who exploit them in some of the harshest and most difficult environments of Asia.

Taxonomy, Description, and Habitat

Yak are members of the subfamily of cattle Bovinae. Although the genetic relationships among its members are not precisely understood, Herwart Bohlken (1958: 167–8, 1958–60: 113–202) argues that yak belong to the genus Bos and subgenus Poëphagus. Moreover, Bohlken draws a further distinction between wild yak, Bos [Poëphagus]mutus Przhelval’skii (1883), and domesticated yak, Bos [Poëphagus]grunniens Linnaeus (1766). Although wild and domesticated yak are interfertile, domesticated yak can be crossed with a variety of other cattle, including common cattle (Bos taurus), and zebu (Bos indicus) to produce hybrids of various types.

Both wild and domesticated yak are massively built, with barrel-shaped bodies carried on legs that are quite short but solid (see Figure II.G.24.1). Although yak have no humps (as zebus do), they do have a dorsal ridgelike prominence that adds to their massive appearance. From this prominence, a short heavy neck slopes downward, ending in a large head with a broad, flat forehead, large eyes, and small ears.

Probably the most conspicuous features of the yak, however, are its horns and hair. The horns are large, dark, and double-curved. That is, they emerge horizontally from either side of the head, curve and extend first upward, then backward. The hair is coarse and shaggy and covers the animal’s body almost entirely. The hair is abundant and is generally 4 or more inches in length. Fringing the chest, lower shoulders, sides, flanks, and thighs of the yak is even longer hair, which almost reaches the ground. The tail, too, is entirely covered by long hair, giving it a pronounced bushy appearance.