Though rare Tibetan antelopes are becoming free from poachers, they are facing new threats, such as rat disasters, enclosure of rangelands and grassland degradation in their natural habitat, the Hoh Xil Nature Reserve on the Qinghai-Tibet plateau.

China's anti-poaching efforts on the reserve have taken an obvious effect to sustain the wild species. However, Tibetan antelopes now have to fight with rats for food, since rats have eaten away pasture in the primitive reserve.

Cega, director of the Hoh Xil Nature Reserve Administration, said that each rat consumes at least 50 kg of graze every year. Xinhua's reporter saw as many as a dozen mouse-holes in one-square meter of land in some areas of the reserve.

Cega told Xinhua that high-plateau rats are proliferating on the pasture. They are also blamed as the chief culprit wrecking the fragile ecology and spurring desertification.

He said that growing amounts of rats are feeding expanding herds of wolves, which are predators of antelopes. Rangers once saw some 30 antelope remains after the horde was attacked by wolves.

The Hoh Xil reserve, once an uninhabited region, is no longer worthy of the title with frequent enclosure of rangelands and other human activities. Some 390 herdsmen from Tibet Autonomous Region and Qinghai Province grazed large herds of sheep and cattle in the reserve area.

Animal researchers worry that yaks and antelopes may mate with the livestock, which would lead to changes in the wild species.

Scientific research in the reserve has found the thawing of glaciers, and rising temperature and water levels. The warming weather is likely to cause more epidemics, which could naturally drive up the death rate of the antelope population.

Rangers said that human activities such as mining, hunting and grazing have left large amounts of baggage and sewage to deteriorate the ecology in the reserve.

The Hoh Xil region, seated 4,500 meters above sea level, is a major natural gene bank for animals living in a frigid zone and higher elevation plants. It is one of the last piece of clean land on earth.

(Xinhua News Agency August 6, 2005)