HANGZHOU, Jan. 11 (Xinhua) -- A total of 15 Chinese mergansers, an endangered bird species under state class-one protection, have been spotted in Wenzhou City in east China's Zhejiang Province, a bird protection association said on Wednesday.
It is the first time that this many Chinese mergansers have been seen in the city, said Wang Xiaoning, secretary-general of the association.
Six of them were found in Yongjia County, while another 9 were found in Wencheng County, according to Wang.
Chinese mergansers have a history of more than 10 million years. There are about 1,000 of them worldwide, and Russia's Far East and China serve as their main breeding ground.
In China, the birds mostly live in the northeastern provinces of Heilongjiang and Jilin, northern Hebei Province, and the south side of the Yangtze River.
In 2014, more than 40 bird-watching associations spotted 441 Chinese mergansers across the country. The number increased to 634 in 2015.
The species has very strict habitat needs, requiring forests of old trees for nests and clear creeks full of small aquatic creatures for food.
"Chinese mergansers are very picky about their water environment. They can be used to monitor water quality," said Wang.