Sex-specific foraging strategies of Adélie penguins (Pygoscelis adeliae): Females forage further and on more krill than males in the Antarctic Peninsula

Abstract

Sexual segregation characterises many animal communities, and in seabirds (including penguins), foraging strategies are known to vary with sex. The forging strategies of Adelie penguins (Pygoscelis adeliae) have been studied to some extent in some Antarctic locations; however, sex-based differences in foraging in this species have only been studied in depth in East Antarctica. Therefore, in this study, we aim to determine whether sexual segregation drives the foraging ecology [in terms of foraging habitat and diet based on analysis of stable carbon (δ13C) and nitrogen (δ15N) isotopes, respectively] of Adelie penguins in the Antarctic Peninsula (Hope Bay) during the breeding season. Our results showed strong sexual isotopic spatial segregation. Females forage for more krill than fish in more offshore, pelagic waters in contrast to males which feed equally on both items in more inshore, benthic waters. These results suggest a link between foraging habitat and diet that differs according to sex, similar to that found in East Antarctica. Given these similarities, we hypothesise that the foraging ecology of Adelie penguins varies with sex throughout the Antarctic continent. Nevertheless, further research in other locations such as in western Antarctica is needed to confirm this hypothesis.