Group of black-necked cranes fly over the Lhasa river valley where they spend the winter season, southwest China's Tibet Autonomous Region, Nov. 23, 2017. Black-necked cranes are often seen in Tibet's river valleys and the region's barley and wheat fields in winter. With an estimated population of around 10,200, the species is classified as "vulnerable" by the International Union for Conservation of Nature (IUCN) and is listed among more than 90 endangered species on China's top protection list, along with the giant panda and golden monkey. (Xinhua/Purbu Zhaxi)