Long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers
Background: Individual variations in the use of the species niche are an important component of diversity in trophic interactions. A challenge in testing consistency of individual foraging strategy is the repeated collection of information on the same individuals. Methodology/Principal Findings: The...
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ftdeakinunifig:oai:figshare.com:article/20985019 2023-05-15T13:57:09+02:00 Long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers L Kernaleguen B Cazelles John Arnould P Richard C Guinet Y Cherel 2012-03-14T00:00:00Z http://hdl.handle.net/10536/DRO/DU:30046863 https://figshare.com/articles/journal_contribution/Long-term_species_sexual_and_individual_variations_in_foraging_strategies_of_fur_seals_revealed_by_stable_isotopes_in_whiskers/20985019 unknown http://hdl.handle.net/10536/DRO/DU:30046863 https://figshare.com/articles/journal_contribution/Long-term_species_sexual_and_individual_variations_in_foraging_strategies_of_fur_seals_revealed_by_stable_isotopes_in_whiskers/20985019 All Rights Reserved Uncategorized arctocephalus-gazella seasonal-changes southern-ocean nitrogen-balance wavelet analysis phoca-vitulina trophic niche population specialization ecology Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics PREDATORS PATTERNS CARBON Text Journal contribution 2012 ftdeakinunifig 2022-11-17T22:08:06Z Background: Individual variations in the use of the species niche are an important component of diversity in trophic interactions. A challenge in testing consistency of individual foraging strategy is the repeated collection of information on the same individuals. Methodology/Principal Findings: The foraging strategies of sympatric fur seals (Arctocephalus gazella and A. tropicalis) were examined using the stable isotope signature of serially sampled whiskers. Most whiskers exhibited synchronous delta C-13 and delta N-15 oscillations that correspond to the seal annual movements over the long term (up to 8 years). delta C-13 and delta N-15 values were spread over large ranges, with differences between species, sexes and individuals. The main segregating mechanism operates at the spatial scale. Most seals favored foraging in subantarctic waters (where the Crozet Islands are located) where they fed on myctophids. However, A. gazella dispersed in the Antarctic Zone and A. tropicalis more in the subtropics. Gender differences in annual time budget shape the seal movements. Males that do not perform any parental care exhibited large isotopic oscillations reflecting broad annual migrations, while isotopic values of females confined to a limited foraging range during lactation exhibited smaller changes. Limited inter-individual isotopic variations occurred in female seals and in male A. tropicalis. In contrast, male A. gazella showed large inter-individual variations, with some males migrating repeatedly to high-Antarctic waters where they fed on krill, thus meaning that individual specialization occurred over years. Conclusions/Significance: Whisker isotopic signature yields unique long-term information on individual behaviour that integrates the spatial, trophic and temporal dimensions of the ecological niche. The method allows depicting the entire realized niche of the species, including some of its less well-known components such as age-, sex-, individual- and migration-related changes. It highlights intrapopulation ... Other Non-Article Part of Journal/Newspaper Antarc* Antarctic Arctocephalus gazella Crozet Islands Phoca vitulina Southern Ocean DRO - Deakin Research Online Antarctic Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
DRO - Deakin Research Online |
op_collection_id |
ftdeakinunifig |
language |
unknown |
topic |
Uncategorized arctocephalus-gazella seasonal-changes southern-ocean nitrogen-balance wavelet analysis phoca-vitulina trophic niche population specialization ecology Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics PREDATORS PATTERNS CARBON |
spellingShingle |
Uncategorized arctocephalus-gazella seasonal-changes southern-ocean nitrogen-balance wavelet analysis phoca-vitulina trophic niche population specialization ecology Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics PREDATORS PATTERNS CARBON L Kernaleguen B Cazelles John Arnould P Richard C Guinet Y Cherel Long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers |
topic_facet |
Uncategorized arctocephalus-gazella seasonal-changes southern-ocean nitrogen-balance wavelet analysis phoca-vitulina trophic niche population specialization ecology Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics PREDATORS PATTERNS CARBON |
description |
Background: Individual variations in the use of the species niche are an important component of diversity in trophic interactions. A challenge in testing consistency of individual foraging strategy is the repeated collection of information on the same individuals. Methodology/Principal Findings: The foraging strategies of sympatric fur seals (Arctocephalus gazella and A. tropicalis) were examined using the stable isotope signature of serially sampled whiskers. Most whiskers exhibited synchronous delta C-13 and delta N-15 oscillations that correspond to the seal annual movements over the long term (up to 8 years). delta C-13 and delta N-15 values were spread over large ranges, with differences between species, sexes and individuals. The main segregating mechanism operates at the spatial scale. Most seals favored foraging in subantarctic waters (where the Crozet Islands are located) where they fed on myctophids. However, A. gazella dispersed in the Antarctic Zone and A. tropicalis more in the subtropics. Gender differences in annual time budget shape the seal movements. Males that do not perform any parental care exhibited large isotopic oscillations reflecting broad annual migrations, while isotopic values of females confined to a limited foraging range during lactation exhibited smaller changes. Limited inter-individual isotopic variations occurred in female seals and in male A. tropicalis. In contrast, male A. gazella showed large inter-individual variations, with some males migrating repeatedly to high-Antarctic waters where they fed on krill, thus meaning that individual specialization occurred over years. Conclusions/Significance: Whisker isotopic signature yields unique long-term information on individual behaviour that integrates the spatial, trophic and temporal dimensions of the ecological niche. The method allows depicting the entire realized niche of the species, including some of its less well-known components such as age-, sex-, individual- and migration-related changes. It highlights intrapopulation ... |
format |
Other Non-Article Part of Journal/Newspaper |
author |
L Kernaleguen B Cazelles John Arnould P Richard C Guinet Y Cherel |
author_facet |
L Kernaleguen B Cazelles John Arnould P Richard C Guinet Y Cherel |
author_sort |
L Kernaleguen |
title |
Long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers |
title_short |
Long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers |
title_full |
Long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers |
title_fullStr |
Long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers |
title_full_unstemmed |
Long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers |
title_sort |
long-term species, sexual and individual variations in foraging strategies of fur seals revealed by stable isotopes in whiskers |
publishDate |
2012 |
url |
http://hdl.handle.net/10536/DRO/DU:30046863 https://figshare.com/articles/journal_contribution/Long-term_species_sexual_and_individual_variations_in_foraging_strategies_of_fur_seals_revealed_by_stable_isotopes_in_whiskers/20985019 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Arctocephalus gazella Crozet Islands Phoca vitulina Southern Ocean |
genre_facet |
Antarc* Antarctic Arctocephalus gazella Crozet Islands Phoca vitulina Southern Ocean |
op_relation |
http://hdl.handle.net/10536/DRO/DU:30046863 https://figshare.com/articles/journal_contribution/Long-term_species_sexual_and_individual_variations_in_foraging_strategies_of_fur_seals_revealed_by_stable_isotopes_in_whiskers/20985019 |
op_rights |
All Rights Reserved |
_version_ |
1766264752163520512 |