Seabirds as Indicators of Marine Food Supplies

AbstractAn integrated approach to the use of seabirds as indicators of marine food supplies is developed, based on proposed relations between food availability and seabird population and behavior parameters. Adult survivorship, breeding success, chick growth, colony attendance, and activity budgets vary with prey availability, but response to food supply occurs at different temporal scales and at different levels of prey availability for each parameter. Seabird data most reliably indicate food availability when monophagous birds are used to monitor temporal variation in prey supplies. Seabird-based data on prey availability are cheaper to obtain than conventional fisheries abundance indices, and may be particularly useful for the many species and areas for which conventional fisheries data are sparse or absent.