The yak is the main bovine on the Tibetan plateau. A heavily built horned animal with a bulky frame, sturdy legs, and rounded cloven hooves, the yak is characterized by long shaggy hair that hangs down below its belly and a dense down-like undercoat. The domestic yak or Bos Grunniens (grunting ox) is a direct descendant of the much larger wild yak, Bos Mutus, (mute ox), now an endangered species found mainly in the Norther plains of Central Tibet. The yak has adapted to high altitudes and thrives at 3000 meters and above. There are presently 13 million yaks on the Tibetan Plateau and beyond, into Mongolia, Eastern Russian, the Himalayan regions and parts of Central Asia.