ZHENGZHOU, Aug. 22 (Xinhua) -- The population of crested ibises has surpassed 200 in a Chinese natural reserve, a result of Sino-Japanese cooperation on the breeding of the endangered bird species.

A total of 100 crested ibises have been released into the wild at the Dongzhai National Natural Reserve in Henan Province, and the births of 114 chicks have been monitored in the wild, said Huang Zhixue, deputy head of the reserve's crested ibis breeding center.

The reserve, perched on the northern side of Dabie Mountain, became a sanctuary for crested ibises in 2007 with the introduction of four such birds from the Beijing Zoo and 13 returned from Japan.

Crested ibises, with their iconic red crests and black long beaks, were thought to be extinct in China until seven wild birds were observed in Shaanxi Province in 1981, a discovery that prompted captive breeding and enhanced protection of the species.

Since 1999, China has been giving crested ibises to Japan, where the last of the wild birds died in 2003, as symbols of friendship. Under an agreement on breeding cooperation, half of the ibises born in Japan would be returned to China.

The breeding center in the Dongzhai reserve was established as a strategy to diversify the habitats of the birds, which had mainly dwelled in Shaanxi.