Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean
11 pages International audience 1. Climatic variation outside the breeding season affects fluctuations in population numbers of seabirds and marine mammals. A challenge in identifying the underlying biological mechanisms is the lack of information on their foraging strategies during winter, when ind...
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Online Access: | https://hal.science/hal-00185936 https://doi.org/10.1111/j.1365-2656.2007.01238.x |
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ftccsdartic:oai:HAL:hal-00185936v1 2024-02-27T08:35:14+00:00 Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean Cherel, Yves Hobson, Keith A. Guinet, Christophe Vanpe, Cécile Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Environment and Climate Change Canada 2007-01 https://hal.science/hal-00185936 https://doi.org/10.1111/j.1365-2656.2007.01238.x en eng HAL CCSD Wiley info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1365-2656.2007.01238.x hal-00185936 https://hal.science/hal-00185936 doi:10.1111/j.1365-2656.2007.01238.x ISSN: 0021-8790 EISSN: 1365-2656 Journal of Animal Ecology https://hal.science/hal-00185936 Journal of Animal Ecology, 2007, 76, pp.826-836. ⟨10.1111/j.1365-2656.2007.01238.x⟩ fur seal nonbreeding period penguin resource partitioning trophic level [SDE.BE]Environmental Sciences/Biodiversity and Ecology info:eu-repo/semantics/article Journal articles 2007 ftccsdartic https://doi.org/10.1111/j.1365-2656.2007.01238.x 2024-01-28T03:19:53Z 11 pages International audience 1. Climatic variation outside the breeding season affects fluctuations in population numbers of seabirds and marine mammals. A challenge in identifying the underlying biological mechanisms is the lack of information on their foraging strategies during winter, when individuals migrate far from their breeding grounds. 2. We investigated the temporal variability in resource partitioning within the guild of five sympatric Subantarctic penguins and fur seals from Crozet Islands. The stable isotopic ratios of carbon ( δ 13 C) and nitrogen ( δ 15 N) for whole blood were measured for penguins and fur seals, as were the isotopic ratios for penguin nails and food. Animals were sampled at two periods, during breeding in summer and at their arrival in the colonies in spring (hereafter winter, since the temporal integration of blood amounting to several months). 3. In summer, δ 13 C and δ 15 N for blood samples defined three foraging areas and two trophic levels, respectively, characterizing four nonoverlapping trophic niches. King penguins and female Antarctic and Subantarctic fur seals are myctophid eaters foraging in distinct water masses, while both macaroni and rockhopper penguins had identical isotopic signatures indicating feeding on crustaceans near the archipelago. 4. Isotopic ratios were almost identical in summer and winter suggesting no major changes in the species niches, and hence, in the trophic structure of the guild during the nonbreeding period. A seasonal difference, however, was the larger variances in δ 13 C (and also to a lesser extent in δ 15 N) values in winter, thus verifying our hypothesis that trophic niches widen when individuals are no longer central place foragers. 5. Winter isotopic ratios of macaroni penguins and male Antarctic fur seals had large variances, indicating individual foraging specializations. The range of δ 13 C and δ 15 N values of male fur seals showed, respectively, that they dispersed over a wide latitudinal gradient (from Antarctica to ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seals Antarctica Crozet Islands King Penguins Southern Ocean Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Antarctic Southern Ocean Journal of Animal Ecology 76 4 826 836 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
fur seal nonbreeding period penguin resource partitioning trophic level [SDE.BE]Environmental Sciences/Biodiversity and Ecology |
spellingShingle |
fur seal nonbreeding period penguin resource partitioning trophic level [SDE.BE]Environmental Sciences/Biodiversity and Ecology Cherel, Yves Hobson, Keith A. Guinet, Christophe Vanpe, Cécile Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean |
topic_facet |
fur seal nonbreeding period penguin resource partitioning trophic level [SDE.BE]Environmental Sciences/Biodiversity and Ecology |
description |
11 pages International audience 1. Climatic variation outside the breeding season affects fluctuations in population numbers of seabirds and marine mammals. A challenge in identifying the underlying biological mechanisms is the lack of information on their foraging strategies during winter, when individuals migrate far from their breeding grounds. 2. We investigated the temporal variability in resource partitioning within the guild of five sympatric Subantarctic penguins and fur seals from Crozet Islands. The stable isotopic ratios of carbon ( δ 13 C) and nitrogen ( δ 15 N) for whole blood were measured for penguins and fur seals, as were the isotopic ratios for penguin nails and food. Animals were sampled at two periods, during breeding in summer and at their arrival in the colonies in spring (hereafter winter, since the temporal integration of blood amounting to several months). 3. In summer, δ 13 C and δ 15 N for blood samples defined three foraging areas and two trophic levels, respectively, characterizing four nonoverlapping trophic niches. King penguins and female Antarctic and Subantarctic fur seals are myctophid eaters foraging in distinct water masses, while both macaroni and rockhopper penguins had identical isotopic signatures indicating feeding on crustaceans near the archipelago. 4. Isotopic ratios were almost identical in summer and winter suggesting no major changes in the species niches, and hence, in the trophic structure of the guild during the nonbreeding period. A seasonal difference, however, was the larger variances in δ 13 C (and also to a lesser extent in δ 15 N) values in winter, thus verifying our hypothesis that trophic niches widen when individuals are no longer central place foragers. 5. Winter isotopic ratios of macaroni penguins and male Antarctic fur seals had large variances, indicating individual foraging specializations. The range of δ 13 C and δ 15 N values of male fur seals showed, respectively, that they dispersed over a wide latitudinal gradient (from Antarctica to ... |
author2 |
Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Environment and Climate Change Canada |
format |
Article in Journal/Newspaper |
author |
Cherel, Yves Hobson, Keith A. Guinet, Christophe Vanpe, Cécile |
author_facet |
Cherel, Yves Hobson, Keith A. Guinet, Christophe Vanpe, Cécile |
author_sort |
Cherel, Yves |
title |
Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean |
title_short |
Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean |
title_full |
Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean |
title_fullStr |
Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean |
title_full_unstemmed |
Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean |
title_sort |
stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the southern ocean |
publisher |
HAL CCSD |
publishDate |
2007 |
url |
https://hal.science/hal-00185936 https://doi.org/10.1111/j.1365-2656.2007.01238.x |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Antarctic Fur Seals Antarctica Crozet Islands King Penguins Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Fur Seals Antarctica Crozet Islands King Penguins Southern Ocean |
op_source |
ISSN: 0021-8790 EISSN: 1365-2656 Journal of Animal Ecology https://hal.science/hal-00185936 Journal of Animal Ecology, 2007, 76, pp.826-836. ⟨10.1111/j.1365-2656.2007.01238.x⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1365-2656.2007.01238.x hal-00185936 https://hal.science/hal-00185936 doi:10.1111/j.1365-2656.2007.01238.x |
op_doi |
https://doi.org/10.1111/j.1365-2656.2007.01238.x |
container_title |
Journal of Animal Ecology |
container_volume |
76 |
container_issue |
4 |
container_start_page |
826 |
op_container_end_page |
836 |
_version_ |
1792041698859155456 |