Qu Yongqiang (R) and Wang Yanming, observers of the Qinghai Lake National Nature Reserve Administration Bureau, observe at the river mouth of Buha river in Northwest China's Qinghai province, Sept 24, 2019. A three-day autumn observation around the Qinghai Lake by the observers of the Qinghai Lake National Nature Reserve Administration Bureau has concluded after the last observation at Daotanghe wetland. Observers studied and analyzed the ecological environment conditions of Qinghai Lake through collecting the records of wetlands and birds of about 20 observation spots along the Qinghai Lake. [Photo/Xinhua]