干旱区生态环境知识资源中心

Wild yaks Bos grunniens survive only on the Tibetan Plateau where they have declined greatly in range and numbers during the past century because of excessive hunting. Wildlife surveys on the Plateau between 1984 and 1994 revealed that yaks per sist in several small populations and in one large tract of alpine steppe and alpine desert, mostly above 4500 m in elevation, which extends over about 400,000 km(2) primarily in the Tibet Autonomous Region. The Chang Tang Reserve, 284,000 km(2) in size, covers a substantial part of this area and contains an estimated 7000-7500 yaks, a third of these in two relatively small areas. The number of wild yaks probably totals around 15,000. Meat hunting, encroachment by pastoralists into the last strongholds, and hybridization between domestic and wild yaks are among the dangers confronting the animals. Only lar ge protected tracts of wilderness as in the northern Chang Tang Reserve can provide wild yaks with a future.