Migratory birds seen in Heihe River wetland in Zhangye, NW China's Gansu

Ruddy shelducks are seen in Heihe River wetland in Gaotai County, Zhangye City, northwest China's Gansu Province, Jan. 17, 2021. Numerous migratory birds have arrived in the wetland to spend the winter. (Photo by Zheng Yaode/Guangming Picture)