Corticosterone and foraging behavior in a diving seabird: The Adelie penguin, Pygoscelis adeliae

• Published in: General and Comparative Endocrinology
• Main Authors: Angelier, Frédéric, Bost, Charles-André, Giraudeau, Mathieu, Bouteloup, Guillaume, Dano, Stéphanie, Chastel, Olivier
• Other Authors: Smithsonian Migratory Bird Center, National Zoological Park, Centre d'Études Biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: Corticosterone; Foraging success; Foraging effort; Satellite tracking; Time-depth-recorder; Penguin; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.ES]Environmental Sciences/Environment and Society; [SDE.MCG]Environmental Sciences/Global Changes; Lower Post; Adelie penguin; Antarc*; Antarctica; Pygoscelis adeliae
• Online Access: https://hal.science/hal-00261835; https://doi.org/10.1016/j.ygcen.2007.12.001

International audience Because hormones mediate physiological or behavioral responses to intrinsic or extrinsic stimuli, they can help us understand how animals adapt their foraging decisions to energetic demands of reproduction. Thus, the hormone corticosterone deserves specific attention because of its influence on metabolism, food intake and locomotor activities. We examined the relationships between baseline corticosterone levels and foraging behavior or mass gain at sea in a diving seabird, the Ade´lie penguin, Pygoscelis adeliae. Data were obtained from free-ranging penguins during the brooding period (Ade´lie Land, Antarctica) by using satellite transmitters and timedepth- recorders. The birds were weighed and blood sampled before and after a foraging trip (pre-trip and post-trip corticosterone levels, respectively). Penguins with elevated pre-trip corticosterone levels spent less time at sea and stayed closer to the colony than penguins with low pre-trip corticosterone levels. These short trips were associated with a higher foraging effort in terms of diving activity and a lower mass gain at sea than long trips. According to previous studies conducted on seabird species, these results suggest that penguins with elevated pre-trip corticosterone levels might maximize the rate of energy delivery to the chicks at the expense of their body reserves. Moreover, in all birds, corticosterone levels were lower post-foraging than pre-foraging. This decrease could result from either the restoration of body reserves during the foraging trip or from a break in activity at the end of the foraging trip. This study demonstrates for the first time in a diving predator the close relationships linking foraging behavior and baseline corticosterone levels. We suggest that slight elevations in pre-trip corticosterone levels could play a major role in breeding effort by facilitating foraging activity in breeding seabirds.