ZHENGZHOU, Dec. 11 -- Twenty-two bustards, which are a rare, protected species, have been spotted on wetland along the Yellow River in central China's Henan Province, it was announced on Friday.

As an extremely-endangered species, bustards are included by the International Center for Birds of Prey (ICBP) in the red book of the world's endangered birds. There are only about 500 bustards in China, said Zhang Yifan, deputy director with the administrative office of the Sanmenxia Yellow River Wetland.

"This is the first sighting of bustards on the wetland this year," Zhang said, adding that observation will continue to help conservation of the species.

Bustards are large, highly terrestrial birds that can grow as large as 70 cm tall. They weigh around 10 kilograms, with males weighing slightly more at about 15 kilograms. They are native to prairies and semidesert areas across Eurasia.