Whooper swans fly over a wetland in Chengshan Township of Rongcheng, east China's Shandong Province, Nov. 27, 2022. (Photo by Li Xinjun/Xinhua)

Egrets are seen at a wetland in Qixingguan District of Bijie, southwest China's Guizhou Province, Nov. 27, 2022. (Photo by Luo Dafu/Xinhua)

A flock of pied avocets fly over the Matou section of the Yihe River in Tancheng County, Linyi City, east China's Shandong Province, Nov. 27, 2022. (Photo by Fang Dehua/Xinhua)

A flock of pied avocets are seen in the Matou section of the Yihe River in Tancheng County, Linyi City, east China's Shandong Province, Nov. 27, 2022. (Photo by Fang Dehua/Xinhua)