Sexual and individual foraging segregation in Gentoo penguins Pygoscelis papua from the Southern Ocean during an abnormal winter

• Published in: PLOS ONE
• Main Authors: Xavier, José C., Trathan, Philip N., Ceia, Filipe R., Tarling, Geraint A., Adlard, Stacey, Fox, Derren, Edwards, Ewan W. J., Vieira, Rui P., Medeiros, Renata, de Broyer, Claude, Cherel, Yves
• Other Authors: British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Marine and environmental research centre - IMAR-CMA (Coimbra, Portugal), University of Coimbra Portugal (UC), School of Biosciences Cardiff, Cardiff University, Department of Invertebrates, Royal Belgian Institute of Natural Sciences (RBINS), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SDE]Environmental Sciences; Antarctic; Austral; Southern Ocean; Antarc*; Antarctic Krill; Euphausia superba; Pygoscelis papua
• Online Access: https://hal.archives-ouvertes.fr/hal-01501413; https://doi.org/10.1371/journal.pone.0174850

International audience Knowledge about sexual segregation and gender-specific, or indeed individual specialization,in marine organisms has improved considerably in the past decade. In this context, wetested the ªIntersexual Competition Hypothesisº for penguins by investigating the feedingecology of Gentoo penguins during their austral winter non-breeding season. We consideredthis during unusual environmental conditions (i.e. the year 2009 had observations ofhigh sea surface and air temperatures) in comparison with the long term average at BirdIsland, South Georgia. Through conventional (i.e. stomach contents) and stable isotopicvalues from red blood cells, plasma and feathers of both male and female Gentoo penguins,we showed that there were significant differences between sexes, with males feeding mainlyon fish (54% by mass) followed by crustaceans (38%) whereas females fed mainly on crustaceans(89% by mass) followed by fish (4%). Themisto gaudichaudii was the most importantcrustacean prey for males (64% by mass; 82% by number; 53% by frequency of occurrence)and females (63% by mass; 77% by number; 89% by frequency of occurrence), contrastingwith all previous studies that found Antarctic krill Euphausia superba were generally the mainprey. Stable isotopic data showed that, in terms of habitat use (based on δ 13C), there weresignificant differences in short-term carbon signatures between males and females (basedon plasma and red blood cells), suggesting that both sexes explored different habitats, withfemales exploring more offshore pelagic waters and males feeding more in coastal benthicwaters. Based on δ 15N, males fed on significantly higher trophic level than females (basedon plasma and red blood cells), in agreement with our diet results., Thus, Gentoo penguinsbehave in a similar manner to other non-breeding penguins species (e.g. king, macaroniand rockhopper penguins), albeit at a smaller spatial scale (as they do not disperse as theseother penguins do), in that they have a wider habitat and trophic niche ...