Yak vs. Bison: 4 Key Differences Explained

The closely related yak (Bos grunniens) and bison (Bison) are sometimes mistaken for each other. They are both enormous herbivorous mammals with humped shoulders and prominent horns. However, despite their similarities, there are four key differences between them. Continue reading to discover what sets these two land mammals apart.

Habitat

One of the main differences between yak and bison is their distribution. Bison live in grasslands, river valleys, and forests across North America and parts of Europe. Once ranging across most of North America, American bison now have a fragmented distribution primarily within national parks and preserves.

The vast majority of the world’s wild yak population is on the Qinghai-Tibetan Plateau, primarily in China. The domestic yak has been introduced to other parts of Asia, such as Mongolia, Nepal, and India. Its distribution has also extended to countries in the Caucasus, a region between the Black and Caspian seas that serves as a natural border between Europe and Asia.

Appearance

Bison and yak are both large, imposing animals; however, they look very different.

Bison are massive bovids characterized by a hump at the shoulder. Their shaggy dark-brown coat is thickest on the head, neck, and forelegs. Both male and female bison have short, curved horns and powerful builds, although males are significantly larger and heavier than females. The average American bison is up to 2,000 pounds, 6 feet tall, and 12 feet long for males, while females average around 1,000 pounds, 7 to 10 feet long, and are between 4 and 5 feet tall at the shoulder.

Yaks also have a heavy body, sturdy legs, and humped shoulders. However, even though their forehead is wide, their face is typically slimmer than that of a bison. Wild yaks are typically black with rusty-brown tints, while domestic yaks can be black, white, gray, brown, or piebald (having mottled patches of white).

Male yaks, called bulls, are significantly larger than females, which are called cows. Males can weigh up to 2,200 pounds and stand over 6.5 feet at the shoulder, while females typically weigh around 660 pounds and stand around 4 to 4.5 feet tall.

Both female and male yaks have horns, although the shape and size differ between the sexes.  Male yaks possess horns that are 20 to 40 inches long and sweep out from the side of their head before curving forward. Females’ horns are smaller, ranging between 11 and 25 inches long with a more upright shape.

Hair and Fur

The hair and fur of bison and yaks share insulating properties but differ significantly in their composition, appearance, and distribution. Both species have a double coat of fur to protect them from extreme cold. This consists of a protective layer of coarse guard hairs and an inner, soft, woolly layer of down hair.

The fur and hair of the American bison are concentrated on the front half, with a massive, dense, and shaggy mane covering the head, shoulders, and hump. The fur on the flanks and hindquarters is much shorter.

Yaks have long, dense hair on their chest, flanks, and thighs. It is distributed as a long, shaggy coat that covers the entire body, with the longest hair hanging almost to the ground around the belly and flanks.

Tail

Yak and bison tails are both used to swat away insects, but they differ in appearance.. A yak’s tail resembles a horse’s tail. It is long and bushy with long hairs covering most of its length.

The bison’s tail is more like a cow’s tail: it is shorter with a tuft of hair on the end.