Red-crowned cranes fly over the Yancheng national rare birds nature reserve, East China’s Jiangsu province, Jan 9, 2016.[Photo/Xinhua]

Red-crowned cranes fly over the Yancheng national rare birds nature reserve, East China’s Jiangsu province, Jan 9, 2016.[Photo/Xinhua]

Red-crowned cranes fly over the Yancheng national rare birds nature reserve, East China’s Jiangsu province, Jan 9, 2016.[Photo/Xinhua]

Red-crowned cranes fly over the Yancheng national rare birds nature reserve, East China’s Jiangsu province, Jan 9, 2016.[Photo/Xinhua]

Red-crowned cranes fly over the Yancheng national rare birds nature reserve, East China’s Jiangsu province, Jan 9, 2016.[Photo/Xinhua]