Relevance of the Behaviour of Seabirds to the Conservation of Marine Environments

Abstract

Studies of the behaviour of marine birds can, in addition to their direct relevance to the conservation of seabird populations, provide useful information on several aspects of the marine environment in general. Indices of the abundance and of the spatial and temporal distribution of their fish prey can potentially be obtained from studies of seabird numbers, distribution, diet, reproductive performance, adult body condition and adult foraging and reproductive behaviour. The relative usefulness of these parameters is evaluated using data from a study of four seabird species in Shetland over a period when detailed, independent information was available on considerable changes in prey population abundance and structure. The results demonstrate that parameters concerned with foraging behaviour offer the most useful indices of the status of prey populations, moreover, the differences between seabird species in their responses to changes in prey availability can be used to provide information on the abundance, distribution and age structure of the fish far more cheaply than conventional fisheries surveys.