A black-headed gull (larus ridibundus) swoops in for food at Dianchi Lake in Kunming, capital of southwest China's Yunnan province, November 29, 2011.

Tens of thousands of black-headed gulls fly to Kunming from Siberia to spend the winter each year since 1985, local media reported.

A woman feeds black-headed gulls at Dianchi Lake in Kunming, capital of southwest China's Yunnan province, November 29, 2011.

Tens of thousands of black-headed gulls fly to Kunming from Siberia to spend the winter each year since 1985, local media reported.

A woman feeds black-headed gulls at Dianchi Lake in Kunming, capital of southwest China's Yunnan province, November 29, 2011.

Tens of thousands of black-headed gulls fly to Kunming from Siberia to spend the winter each year since 1985, local media reported.

A man feeds black-headed gulls at Dianchi Lake in Kunming, capital of southwest China's Yunnan province, November 29, 2011.

Tens of thousands of black-headed gulls fly to Kunming from Siberia to spend the winter each year since 1985, local media reported.

A black-headed gull is fed at Dianchi Lake in Kunming, capital of southwest China's Yunnan province, November 29, 2011.

Tens of thousands of black-headed gulls fly to Kunming from Siberia to spend the winter each year since 1985, local media reported.