TOKYO - Japanese authorities on Saturday held a ceremony in northern Japan's Niigata airport to transfer eight of 17 crested ibis birds to China which supplied their ancestors.

The rare birds, including six males and two females, were born in Sado, Niigata prefecture. The event marked the fifth of its kind since a program was initiated in 2002. And a total of 28 crested ibis birds have been transfered to China.

Once common in Japan, China, Russia and the Korean Peninsula, zoologists thought the crested ibis became extinct in the first half of the 20th century. But in 1981, seven crested ibis were found in Shaanxi's Yangxian County.

Japan has been endeavoring to reintroduce the endangered species to the wild. The country saw its last wild crested ibis die in 2003.  

China presented a pair of the birds to Japan in 1998. Another three of the birds were later given as gifts to Japan.

According to statistics, there are about 30 of the birds in the wild and 158 in captivity In Japan.  In China, the number of the birds has risen to an estimated 1,617, including 997 in the wild, according to administration statistics.