title: Combined bio-logging and stable isotopes reveal individual specialisations in a benthic coastal seabird, the Kerguelen shag.
abstract: Individual specialisations, which involve the repetition of specific behaviours or dietary choices over time, have been suggested to benefit animals by avoiding competition with conspecifics and increasing individual foraging efficiency. Among seabirds, resident and benthic species are thought to be good models to study inter-individual variation as they repetitively exploit the same environment. We investigated foraging behaviour, isotopic niche and diet in the Kerguelen shag Phalacrocorax verrucosus during both the incubation and chick-rearing periods for the same individuals to determine the effect of sex, breeding stage, body mass and morphometrics on mean foraging metrics and their consistency. There were large differences between individuals in foraging behaviour and consistency, with strong individual specialisations in dive depths and heading from the colony. Stable isotopes revealed specialisations in feeding strategies, across multiple temporal scales. Specifically, individuals showed medium term specialisations in feeding strategies during the breeding season, as well as long-term consistency. A clustering analysis revealed 4 different foraging strategies displaying significantly different δ15N values and body masses. There were no sex or stage biases to clusters and individuals in different clusters did not differ in their morphology. Importantly, the results suggest that the different strategies emphasized were related to individual prey preferences rather than intrinsic characteristics.
authors.affiliation: School of Life and Environmental Sciences, Deakin University (Burwood Campus), Geelong, Victoria, Australia.
authors.forename: Elodie C M
authors.identifier: http://orcid.org/0000-0002-6387-3357
authors.initials: EC
authors.lastname: Camprasse
authors.affiliation: Centre d'Etudes Biologique de Chizé (CEBC), Centre National de la Recherche Scientifique, UMR 7372 du CNRS-Université de La Rochelle, Villiers-en-Bois, Deux-Sèvres, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Cherel
authors.affiliation: School of Life and Environmental Sciences, Deakin University (Burwood Campus), Geelong, Victoria, Australia.
authors.forename: John P Y
authors.initials: JP
authors.lastname: Arnould
authors.affiliation: CSIRO Land and Water, Canberra, Australian Capital Territory, Australia.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Hoskins
authors.affiliation: Centre d'Etudes Biologique de Chizé (CEBC), Centre National de la Recherche Scientifique, UMR 7372 du CNRS-Université de La Rochelle, Villiers-en-Bois, Deux-Sèvres, France.
authors.forename: Charles-André
authors.initials: CA
authors.lastname: Bost
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001717:Birds; D005247:Feeding Behavior; D007554:Isotopes; D011235:Predatory Behavior; D058998:Remote Sensing Technology
chemical_list: D007554:Isotopes