Escape distances from human pedestrians by staging waterbirds in a Danish wetland

Abstract

To aid planning of public access routes and the zoning of recreational activity in a Danish restored wetland, variation in the reactions of staging waterbirds to human activity were explored, using escape distances (measured as the distance at which the birds flush) as an index of sensitivity to pedestrians. Manipulative experiments showed species-specific responses in escape distances, including effects of body mass, flock size, flock composition, visibility of the stimulus to the birds and season. Mean escape distances increased with the mean body mass recorded for each species, although Wigeon Anas penelope flushed at greater distances than expected for their size. Birds in mixed flocks of Mallard Anas platyrhynchos and Teal Anas crecca reacted at longer distances than those in single species flocks for either species. Grey Heron Ardea cinerea escape distances increased through the autumn. Information about escape distances can be useful for advising on reserve design and for planning access within reserves, but there was evidence that waterbird escape distances are sitespecific which limits their wider applicability