on 2008/4/3 13:03:50
CHINESE conservationists have been fumbling for ways to rein in an overpopulation of the blue sheep.
The blue sheep is a protected wild species of sheep mainly living in the Helan Mountain, which lies at the meeting of Ningxia Hui and Inner Mongolia autonomous regions.
Before 1983, the hunting of blue sheep caused the animal's population to fall sharply to the endangered level. Central and local governments then started protecting the animal in 1988, when the Helan Mountain Nature Reserve, covering an area of 153,333 hectares, came into being.
The blue sheep population has been increasing rapidly over the past decades at the reserve, from fewer than 1,800 in 1983 to 15,000 at present.
They have almost no natural enemies, according to Hu Tianhua, chief of the scientific research and publicity of the reserve administration.
Wolves and other large carnivores used to live in the area but disappeared decades ago because of hunting and land development, said Hu.
The blue sheep population has reached 19 on each square kilometer of land, higher than the limit of 17.6, partly because of the animal's ability to reproduce quickly.
Sun Guoliang, chief of forest conservation section on the reserve, noticed a decline in the condition of the animals in the wake of the rise in the blue sheep population.
"In the past, blue sheep were much larger and ran very fast and vigorously. But today they are smaller and smaller," said Sun.
The sharp increase in the sheep's population has also harmed the ecological balance of the nature reserve they inhabit, according to Bai Qingsheng, deputy chief of the forest resource section of Bureau of Forestry in Ningxia Hui Autonomous Region.
"Overpopulation of the blue sheep has made it hard for the vegetation around the Helan Mountain," said Bai. "The blue sheep has strong reproductive capabilities and a good appetite as well.
"They eat not only grass but also shrubs, which has caused great damage to the vegetation."
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