More sick and hungry giant pandas than in past winters may seek food at lower altitudes in China's earthquake-affected areas, straining facilities at the local panda research centre, Xinhua news agency reported.

The devastating May 12 Sichuan earthquake caused landslides and destroyed some of the wild pandas' habitat, reducing supplies of their main source of food, bamboo, in the range of 2,500 metres to 3,200 metres where they normally live.

"They came down the mountains so early this year and that's why we predict there will be a worse situation for the wild pandas this winter," said Zhang Guiquan, assistant director of the Wolong Nature Reserve Administration.

In normal winter periods from December to March, four to five wild pandas are found at lower levels, seeking food or showing signs of illness, but Zhang said two had already been found by local residents in late October.

"Some of them may carry unknown bacteria or have infectious diseases, which will endanger the pandas in captivity," said Tang Chunxiang, chief veterinarian at the China Conservation and Research Center for the Giant Panda, where one of the pandas was taken.

The centre has already taken 53 pandas that had been living at the Wolong Nature Reserve. One panda in the reserve, the largest for pandas in China, died and one went missing after the massive quake.

There are still seven pandas remaining in Wolong, Mr Zhang said, adding, "We have to get prepared to receive more sick, wild pandas."