Black-necked cranes fly over the National Nature Reserve of Black Necked Cranes in Huize County, southwest China’s Yunnan province, Feb 1, 2015. The National Nature Reserve, located at Daqiao Township of Huize, witnessed the arrival of an increasing number of migratory birds in the winter time.[Photo/Xinhua]

Bar-headed geese fly over the National Nature Reserve of Black Necked Cranes in Huize County, southwest China’s Yunnan province, Feb. 1, 2015. The National Nature Reserve, located at Daqiao Township of Huize, witnessed the arrival of an increasing number of migratory birds in the winter time.[Photo/Xinhua]

Birds rest at a lake in the National Nature Reserve of Black Necked Cranes in Huize County, southwest China’s Yunnan province, Feb 1, 2015. The National Nature Reserve, located at Daqiao Township of Huize, witnessed the arrival of an increasing number of migratory birds in the winter time.[Photo/Xinhua]

Black-necked cranes and bar-headed geese fly over the National Nature Reserve of Black Necked Cranes in Huize County, southwest China’s Yunnan province, Feb 1, 2015. The National Nature Reserve, located at Daqiao Township of Huize, witnessed the arrival of an increasing number of migratory birds in the winter time.[Photo/Xinhua]

Black-necked cranes look for food at the National Nature Reserve of Black Necked Cranes in Huize County, southwest China’s Yunnan province, Feb 1, 2015. The National Nature Reserve, located at Daqiao Township of Huize, witnessed the arrival of an increasing number of migratory birds in the winter time.[Photo/Xinhua]