A Chinese crested tern stands on the head of another bird on Wuzhishan Island in Dinghai district of Zhoushan. [Photo/zjol.com.cn]

Chinese crested terns, or Sterna bernsteini, returned to Wuzhishan Island in Dinghai district of Zhoushan, East China's Zhejiang province, in May after spending eight winter months in South China.

The terns will breed on the island.

There are less than 150 adult Chinese crested terns in the world. Because they are so rare, these creatures are often dubbed "the bird of myth".

Chinese crested terns were not found for 60 years, and many thought they had gone extinct. In 2000, they reappeared on Mazu Islands in Fujian province.

Four years later, a Chinese crested tern was found on Jiushan Islands in Xiangshan district of Ningbo, marking the first sighting in Zhejiang province. In 2008, Chinese crested terns bred two baby birds on Wuzhishan Island.

Xiangshan and Dinghai have since 2013 and 2015 respectively started protecting the breeding habitat of Chinese crested terns to repopulate the species. The two districts are now important breeding habitats of Chinese crested terns in the world.

After more than 10 years of efforts, Chinese crested terns have got out of the threat of extinction for temporary.