Chinese Mergansers, an endangered bird species, fly in Longhu Mountain scenic area in Yingtan, east China's Jiangxi Province, on Dec. 18, 2018. About 80 Chinese Mergansers were spotted in the Longhu Mountain scenic area to pass the winter, thanks to a series of measures taken by local authorities to make sure of the safety of the wintering birds. (Xinhua/Song Zhenping)