Habitat use of the coastal zone of the German North Sea by surface-feeding seabirds
In contrast to diving species, foraging skills of surface-feeding seabirds (such as gulls and terns) are limited, as this group is only able to exploit the uppermost zone of the water column. On the other hand, the coastal zone of the German North Sea coast provides a rich habitat mosaic for opportunistic species. A combination of analysis of distribution patterns, behaviour and diet choice revealed that species adjusted their distribution and behaviour to match the temporally varying food abundance. A variety of parameters such as weather, anthropogenic activities, tide, time of day and year strongly influenced their habitat use and provided the opportunity for niche segregation. The present work indicates that surface-feeding seabirds are highly valuable as bioindicators to monitor temporal and spatial changes within their foraging habitats.