Using carbon and nitrogen isotopic values of body feathers to infer inter- and intra-individual variations of seabird feeding ecology during moult

• Published in: Marine Biology
• Main Authors: Jaeger, Audrey, Blanchard, Pierrick, Richard, Pierre, Cherel, Yves
• Other Authors: Centre d'études biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique (CNRS), Evolution et Diversité Biologique (EDB), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: geo; anthro-bio; Indian; Crozet Islands; Diomedea exulans
• Online Access: https://doi.org/10.1007/s00227-009-1165-6; https://hal.archives-ouvertes.fr/hal-00378579

International audience To determine whether stable isotope measurements of body feathers can be used to investigate the isotopic niche of moulting (inter-nesting) adult seabirds, we examined the stable carbon (δ13C) and nitrogen (δ15N) isotopic composition of body feathers of breeding wandering albatrosses (Diomedea exulans) from Crozet Islands, southern Indian Ocean. First we showed that the isotopic composition of body feathers was not signiWcantly diVerent from that of wing feathers, being thus a safe alternative to Xight feathers whose collection impairs the birds' Xying ability. Second, we looked at the variances in δ13C and δ15N values resulting from the isotopic measurement of a single feather, four diVerent feathers, and a pool of four feathers per bird, to delineate the best isotopic analytical procedure. A twostep protocol is proposed that allows investigating both the intra- and inter-individual components of the niche width of the species. In a Wrst step, isotopic measurements on a single feather per bird are used to deWne isotopic specialist from isotopic generalist populations. In a second step and for generalist populations only, measurements on additional (three) feathers per bird are used to delineate type A from type B isotopic generalists (Bearhop et al. in J Anim Ecol 73:1007–1012, 2004). Third, from a biological point of view, our data showed diVerent moulting isotopic niches for adult males and females, and also within female wandering albatrosses. Since the isotopic composition of body feathers in this species reXects that of wing feathers, our results suggest that, after validation, body feathers have the potential for investigating the foraging ecology of other Procellariiforms and seabirds during the poorly known inter-nesting period.