Seasonal changes in waterbirds population and movements of Great Black-headed Gull Larus ichthyaetus at Keluke Lake of Qinghai,China

A study on seasonal dynamic of waterbirds was conducted from 2008 to 2010 at Keluke Lake,Qinghai Province,China.The study was to establish waterbird baseline information for the surveillance of avian influenza and wetland conservation and management at Keluke Lake.A total of 34828 waterbirds,belonging to 54 species,11 families and 6 orders,were recorded during the survey.There were 28445 geese and ducks,accounting for 81.7% of all waterbirds counted,followed by gulls and shorebirds.April and October were two peak periods for spring and fall migrations of waterbirds at Keluke Lake,respectively.Satellite tracking on Great Black-headed Gulls Larus ichthyaetus breeding at Qinghai Lake of Qinghai province showed that Keluke Lake was an important stopover site of the gulls.The time they spent during fall migration varied between years.In 2007,the gulls stayed very short,likely resulted from a road construction occurring an area normally as the home range of the gulls.The timing of their arriving at the lake during spring migration possibly related to the ice melting at Qinghai Lake,the quicker the ice melted at Qinghai Lake,the earlier the gulls flew to Qinghai Lake from Keluke Lake.