Tourists view black-headed gulls at Haigeng dam in Kunming, capital of southwest China's Yunnan Province, Jan. 1, 2019. Migratory black-headed gulls became an attraction for tourists during the New Year holiday. (Xinhua/Hu Chao)

Tourists view black-headed gulls at Haigeng dam in Kunming, capital of southwest China's Yunnan Province, Jan. 1, 2019. Migratory black-headed gulls became an attraction for tourists during the New Year holiday. (Xinhua/Hu Chao)