The wild yak Bos mutus is one of the most charismatic members of the Tibet/Qinghai Plateau fauna, and 19th century explorers to the plateau described vast herds. Overhunting, in particular, has greatly reduced wild yak populations and forced them into remote areas. The species is categorized as Vulnerable on the IUCN Red List and as a Class 1 protected animal in China. Introgression with domestic yaks is another threat, and the wild yak population of the Arjinshan Nature Reserve is particularly important because Uigher herders in and around Arjinshan do not have the tradition of raising yaks. We provide information on the status of the wild yak in Arjinshan based on observations in 1993 and on vehicle surveys during 1998–2009 and point samples from 2009. The steppes of north-east Arjinshan are the most important area, and we saw c. 1,700 yaks there in winter 2008. We saw more yaks in the north-east on similar routes driven in winter 2008 compared to winter 2005, suggesting that the wild yak population in Arjinshan is stable or increasing.
