
Birds fly at the Beidagang wetland in Tianjin, north China, March 21, 2015. The wetland's administrative staff recorded more than 6,000 migrant birds here, as the weather gets warmer. (Xinhua/Yue Yuewei)

Birds fly at the Beidagang wetland in Tianjin, north China, March 21, 2015. The wetland's administrative staff recorded more than 6,000 migrant birds here, as the weather gets warmer. (Xinhua/Yue Yuewei)