The Yak is native to highland pasture areas, and lives in world's highest place. Reputed as the "Boat of the Plateau," it can clamber nimbly over rough terrain at an elevation of as high as 6,100 meters.
Yaks are essential to the life of the Tibetans. Docile and powerful, the yak is the most useful of domestic mammals at high elevations and serves as a mount, a beast of burden, and is used as a major source of milk and meat as well as wool production.
The yak was probably domesticated in Tibet during 900-1,000 years BC and domesticated animals now thrive in the high plateaus and mountains of Central Asia.
The yak is supremely well adapted to the harsh highlands with its thick coat, great lung capacity, and ability to clamber nimbly over rough terrain. Even its blood cells are designed for high elevations -- they are about half the size of those of cattle and are at least three times more numerous, thus increasing its blood's capacity to carry oxygen. Its thick coat and low number of sweat glands are also efficient adaptations for conserving heat. In winter, the yak survives temperatures as low as - 40 C. They serve as the means of highland transportation because of their tolerance of cold in the snowy mountains.
Tibetan Yaks were formerly ranched and used for transporting goods. Today with the construction of more highways and the increased use of modern agricultural equipment, yaks are rarely used in this way. Instead, they are raised for wool, milk and meat.
Yaks mostly graze and live on China's Qinghai-Tibet Plateau, known as the "roof of the world," and on nearby highlands which reach an elevation of more than 3,000 meters.