Self-foraging vs facilitated foraging by Lesser Black-backed Gull (Larus fuscus) at the Frisian Front, the Netherlands

The Lesser Black-backed Gull, Larus fuscus Linnaeus, 1758, is a surface feeder with a broad prey spectrum that forages in the North Sea on subsurface pelagic fishes and crabs swimming within 0.6 m of the sea surface. In July 2006 and in July/August 2009, we surveyed the Frisian Front area in the southern North Sea (53.4°N–54.3°N, 4.0°E–5.5°E) to determine the prey base for Lesser Black-backed Gulls. In July/August 2009, we conducted bird counts...