Swans are seen in the Beidagang Wetland in north China's Tianjin, Dec. 3, 2019. Migratory birds have flocked to the wetland for a winter stopover. (Xinhua/Li Ran)
Migratory birds flock to Beidagang Wetland for winter stopover
Source: Xinhua| 2019-12-03 22:13:40|Editor: Wang Yamei
