The deadly May 12 earthquake and numerous aftershocks have forced forestry workers to halt patrols in China's largest giant panda reserve, which borders Sichuan and Gansu provinces in western China.

"The quake and thousands of aftershocks have caused landslides and cut off mountain roads," said Huang Huali, deputy director of the Baishuijiang Nature Reserve Administration.

Huang and his colleagues have also been forced to stop an annual census of giant pandas in the 220,000-hectare area of mountains covered with lush bamboo forests. "We've not been able to get into the heart of the forests to check if the giant pandas are okay."

Shortly after the quake, some workers ventured into the mountains. "No dead pandas were found then," said Huang. "But we decided to call the workers back amid continuous aftershocks."

The latest national census of giant pandas, which lasted from 1999 to 2001, counted 103 of the animals in Baishuijiang, the largest of China's 55 giant panda reserves. The area is within 100 kilometers of the hardest-hit counties of Sichuan.

Huang said the panda habitat is covered with virgin forests that could prove ideal shelter from geological disasters. "Besides, wild animals are normally more alert and respond faster to natural disasters than human beings. We hope all the pandas are safe."

He said his administration is ready to check out the pandas' situation "as soon as it's safer."

The main quake and its many aftershocks are feared to have damaged the pandas' favorite food -- arrow bamboo -- and disrupted the animal's mating and reproductive cycles, said Huang. "Spring is the mating season for pandas. If scared, the animals might be even less interested in mating."