China's conservation work for the endangered crested ibis is facing new challenges, including an increasing mortality rate due to inbreeding, bird experts have warned.

Zoologists thought the crested ibis, once widespread in Japan, China, Russia and the Korean Peninsula, became extinct in the first half of the 20th century, until seven crested ibis were accidentally found in Yangxian county, in Northwest China's Shaanxi province, in 1981.

Wednesday's China's Daily quoted Chinese forestry authority's sources as saying due to the huge effort put into species protection since 1981, the number of crested ibis in China has risen to an estimated 1,617, including 997 in the wild.

However, officials and experts convened at a meeting held by the State Forestry Administration on crested ibis protection in Xi'an on Monday warned although the ibis population exceeds 1,000, the birds were still not free from the threat of extinction.

Fang Shengguo, director of the State Conservation Center for Gene Resources of Endangered Wildlife under Zhejiang University, said ornithologists used inbreeding in the early stages of protection so that numbers of the precious birds could increase quickly, but that method had consequences.

"Studies have proved that as a result of inbreeding, crested ibis have the lowest genetic diversity of all endangered birds," Fang said.

"It means a high mortality rate and more physical defects for hatched chicks."

He said the bird has lost the ability to migrate. If an unexpected natural disaster occurred in Shaanxi province or an infectious disease spread through the area, the ibis population could be greatly reduced.

He suggested the government should collect genetic information from all crested ibis and establish a genetic database as soon as possible.

(Xinhua News Agency December 22, 2010)