More than 200 critically endangered wild golden yaks, a species once believed to be extinct, roam wild in a reserve in southwest China\'s Tibet Autonomous Region, said local forestry officials on Thursday. The yaks are in Changtang Nature Reserve, a 200,000-square km area in Tibet\'s Ngari Prefecture where more than 400 animal species live, including the endangered Tibetan antelope and the kiang, or wild Tibetan ass. The wild golden yak, known for its lustrous fur, is the rarest yak and unique to Changtang. \"It\'s very difficult to locate the wild golden yak because the animal has an acute sense of smell and runs away whenever it scents humans,\" said Kamgya Tsering, head of the forestry department of Rutog County in Ngari Prefecture. He said the yaks are docile and move around serenely. Local Tibetans see them as \"holy yaks\". The wild yak population has grown from 170 in 2011 to more than 200, thanks to effective protection and the fight by local forestry and public security bureaus against illegal poaching .