Tourists gathered to watch and take photos of black-headed gulls at Dianchi Lake in Kunming, capital of southwest China's Yunnan Province on Tuesday. /CFP Photo

It is said to be the 32nd year that black-headed gulls have migrated to Kunming to pass the winter. Dianchi is seen as the best sightseeing spot for locals and tourists alike to encounter the lovely birds. /CFP Photo

The black-headed gull is rated “vulnerable” by the IUCN, and people need to take care when feeding them. The total population of this species of gull is estimated to be between 21,000 and 22,000, with numbers believed to be declining, according to reports. /CFP Photo