Foraging trips and isotopic niche of chick-rearing South Georgian diving petrels from the Kerguelen Islands

• Published in: Marine Ecology Progress Series
• Main Authors: Bost, Charles-André, Delord, Karine, Cherel, Yves, Miskelly, Colin, Carravieri, Alice, Bustamante, Paco, Arnould, J. P. Y., Fromant, Aymeric
• Other Authors: 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), Museum of New Zealand Te Papa Tongarewa, LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Institut national des sciences de l'Univers (INSU - CNRS)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), School of Life and Environmental Sciences Burwood, Australia, Deakin University Burwood
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: At-sea distribution; Trophic niche; Procellariiformes; Pelecanoides georgicus; Southern Ocean; [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; Kerguelen; Kerguelen Islands; The Antarctic; Antarc*
• Online Access: https://hal.science/hal-03651876; https://hal.science/hal-03651876/document; https://hal.science/hal-03651876/file/Bost%20et%20al.%202022%20MEPS.pdf; https://doi.org/10.3354/meps14029

International audience Seabirds are central place foragers, relying on prey that is patchily distributed and of variable predictability. Species travelling at a high energetic cost are more strongly dependent on spatially predictable prey. This is the case of diving petrels Pelecanoides spp., which are small Procellariiformes that feed by pursuit diving and travel by flapping constantly. Despite their abundance and importance as zooplankton consumers, information on the foraging strategy of diving petrels is still lacking. The detailed at-sea movements and the trophic niche of the South Georgian diving petrel Pelecanoides georgicus was investigated for the first time using miniaturized GPS and the stable isotope method, respectively. Overall, South Georgian diving petrels from the Kerguelen Islands performed unexpected, direct and long-distance trips (mean foraging range: 191 to 217 km) to the Antarctic Polar front, south of the archipelago. This foraging ground is a productive and predictable area, where the birds stopped and fed at the distal part of their trip. Blood isotopic values indicate that the tracked birds fed consistently on macrozooplankton. Such a distant oceanic feeding strategy contrasts with the coastal foraging patterns of the closely related common diving petrel P. urinatrix. Commuting to a more distant but shallower resource allows South Georgian diving petrels to cope with its high commuting costs, and to segregate spatially from the sympatric common diving petrel during the breeding season.