Massaal fouragerende Dwergmeeuwen Larus minutus voor de Hollandse kust in april 1996

On 16-18 April 1996, a large flock of feeding Little Gulls Lams minutus was observed at 8-10 km offshore the province of Noord-Holland, together with Common/Arctic Terns Sterna himndo/paradisaea, a single Black Tern Chlidonias niger and at least 20 Great Cormorants Phalacrocorax carbo. Approximately 1000 Little Gulls were feeding on 17 April, but it could not be established what the birds were feeding on. The flock stretched over several km, along the coastal front separating riverine, coastal waters from more saline North Sea water. During seabird surveys conducted between 1985- 1993, comparably large flocks were never encountered. The largest numbers during offshore surveys in these years were always seen in coastal waters. As during seawatching the largest numbers are usually counted with wind varying between north and east, it is concluded that the occurrence of large numbers of staging Little Gulls was influenced by the very calm weather during this part of their migration, enabling the gulls to feed at the coastal front, which is particularly well-developed under these circumstances.