Spatial distribution and time budget of radio-tagged grey herons, Ardea cinerea, during the breeding season


  • 2,*Institute of Nature Conservation, Kiewitdreef 3, B-3500 Hasselt, Belgium


Spatial distribution of foraging grey herons during the breeding season seemed to be determined by a trade-off between costs and benefits of area sampling versus site fidelity. Breeding birds with little experience of the area spent more time exploring than birds with more experience in the early stages of reproduction. Non-breeding herons and first-year breeders showed little site fidelity. Time budgets appeared to be affected mainly by daily changes in food availability and, for breeding birds, by demands of the brood.