Bos grunniens mutus
status: Vulnerable, IUCN Endangered, ESA
range: China, India, Nepal
Description and biology
The wild yak is a rare and mysterious animal. Its huge body is covered with coarse, shaggy, dark brown hair that hangs almost to the ground. Its muzzle is white. The animal has a large, drooping head, humped shoulders, and short legs. The average male wild yak has a head and body length of 10.75 feet (3.3 meters) and stands 5.5 to 6.5 feet (1.7 to 2 meters) tall at its shoulder. It weighs between 1,800 and 2,200 pounds (820 and 1,000 kilograms). Its upward curved horns are dark and may grow up to 3 feet (0.9 meter) long. Females are substantially smaller.
Wild yaks feed on mosses and lichens (organisms composed of a fungus and an alga) while inhabiting areas at high elevations. At lower elevations, they feed on mosses, herbs, and grasses. Because vegetation is often scarce in their habitat, the animals often cover great distances looking for food. A known predator is the Tibetan wolf.
Males and females form separate herds. During mating season, which begins in September, the herds come together and the males compete with each other over the right to mate with available females. After a gestation (pregnancy) period of 258 days, a female wild yak gives birth to a single calf. The calf then nurses for up to a year.
Habitat and current distribution
Although there are millions of domesticated yaks in the world today, wildlife biologists (scientists who study living organisms) estimate that there are less than 10,000 wild yaks today. They inhabit isolated patches on the Tibetan Plateau at elevations between 13,500 and 20,000 feet (4,115 and 6,096 meters).
History and conservation measures
The wild yak's range once extended into northern Siberia. Biologists believe the animal's population was still quite large at the beginning of the twentieth century. Since that time, excessive hunting has reduced the number of wild yaks to a dangerously low level. Humans have always valued the animal's meat, hide, and coat. Even though the wild yak is protected by international treaties, hunting continues. The Chinese government has been guilty of allowing foreign hunters to kill the animals for sport.
Because of the wild yak's remote mountain habitat, the enforcement of existing laws and the development of conservation plans is almost impossible. As a result, the surviving animals remain in grave danger.