Black-necked cranes arrive at nature reserve to spend winter in China's Guizhou

Black-necked cranes are seen at the Caohai National Nature Reserve in Yi-Hui-Miao Autonomous County of Weining, southwest China's Guizhou Province, Nov. 29, 2018. Thousands of black-necked cranes have arrived here to spend the winter time. (Xinhua/Wang Chunliang)?