The discovery of about 10 wild yak carcasses in the last two days has aroused some concern in the western province of Qinghai, but reports yesterday said that at least nine of them had died from old age.
   
"This is the first time we have seen so many wild yaks die at the same time within a small area of 20 square kilometers," said Duojie, head of the local forest police, after they were first found, "We will work with the local department for animal epidemic prevention to find the cause."

According to China Central Television (CCTV) yesterday, about 10 wild yaks, protected by law, had been found dead in a forest in the Yeniugou region of Golmud, which lies in the Kunlun Mountains.

Today, CCTV reported that a team of local police and animal epidemic prevention officers had discovered nine of them in the areas of Sidaogou, Runiugou and Yuxufeng.

A local vet, Li Wenchang, said the deaths of the nine were from old age and had taken place over one or two months.

But after the initial discovery, experts on Qinghai-Tibet Plateau wildlife had said that, of the factors that may have been involved, old age was not one of them.

Dawa Tsering, director of the Worldwide Fund for Nature's Tibet office, told China Daily yesterday that spring is always a difficult time for animals living in the wild.
   
"The yaks have endured a long and cold winter and expected to get fresh grass, but they may not have had enough to eat as a result of drought and overgrazing," he said.
   
Their habitat has been shrinking on the plateau as local animal husbandry develops, and Tsering added that spring is a mating season so they could acquire infections from domesticated yaks.
   
Nyima Wangdu, professor of biology at Tibet University, had agreed yesterday that they may have died from illness, but Wang Hongjia, director of the Wildlife Protection Station in southwest China's Sichuan Province, said it would be difficult to identify the disease if this was the case.

The Qinghai-Tibet Plateau cuts across the Xizang Tibetan and Xinjiang Uygur autonomous regions, and the provinces of Qinghai, Gansu, Sichuan and Yunnan, with an average altitude of over 3,000 meters.

(China Daily April 7, 2005)