Padrões de forrageio de Phaethon lepturus no Atlântico Equatorial

Abstract

Tropical seabirds live in oligotrophic environments with prey patchly distributed and present behavioral and physiological responses to contrains imposed by oceanographic characteristics. This study investigates movement ecology of the pantropical white-tailed tropicbird Phaethon lepturus Daudin, 1802 on its Equatorial Atlantic colony, located at Fernando de Noronha Archipelago using miniaturized GPS loggers. The species has a pelagic, solitary and generalist biology. On Pacific and Indian oceans distance from colony limitates its choice on foraging grounds and oceanic features such as Sea Surface Temperature, chlorophyll a (as a proxy for primary productivity) and salinity dictate their at-sea distribution. Our results show alternation between short and long foraging trips, alternation between members of a pair in chick-attendance and at-sea occurrence, significant difference between activity modes in short and long trips and association among tropicbirds and STT and turbidity while searching for food patches. We hypothetize that these parameters are related to preys availability, as flyingfish occur in warm oceanic areas and the Waters around the Arquipelago are most favorable to their occurrence on its southwest direction.