Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina)
The evolution of resource specializations is poorly understood, especially in marine systems. The southern elephant seal (Mirounga leonina) is the largest of the phocid seals, sexually dimorphic, and thought to prey predominantly on fish and squid. We collected vibrissae from male and female souther...
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ftpubmed:oai:pubmedcentral.nih.gov:1664629 2023-05-15T16:05:13+02:00 Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina) Lewis, Rebecca O'Connell, Tamsin C Lewis, Mirtha Campagna, Claudio Hoelzel, A. Rus 2006-08-08 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1664629 http://www.ncbi.nlm.nih.gov/pubmed/17015314 https://doi.org/10.1098/rspb.2006.3642 en eng The Royal Society http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1664629 http://www.ncbi.nlm.nih.gov/pubmed/17015314 http://dx.doi.org/10.1098/rspb.2006.3642 © 2006 The Royal Society Research Article Text 2006 ftpubmed https://doi.org/10.1098/rspb.2006.3642 2013-08-31T11:17:04Z The evolution of resource specializations is poorly understood, especially in marine systems. The southern elephant seal (Mirounga leonina) is the largest of the phocid seals, sexually dimorphic, and thought to prey predominantly on fish and squid. We collected vibrissae from male and female southern elephant seals, and assessed stable C and N isotope ratios along the length of the vibrissae. Given that whiskers grow slowly, this sampling strategy reflects any variation in feeding behaviour over a period of time. We found that isotopic variation among females was relatively small, and that the apparent prey choice and trophic level of females was different from that for males. Further, males showed a very broad range of trophic/prey choice positions, grouped into several clusters, and this included isotopic values too low to match a broad range of potential fish and cephalopod prey tested. One of these clusters overlapped with data for South American sea lions (Otaria flavescens), which were measured for comparison. Both male southern elephant seals and southern sea lions forage over the continental shelf, providing the potential for competition. We discuss the possibility that individual southern elephant seals are pursuing specialist foraging strategies to avoid competition, both with one another, and with the South American sea lions that breed nearby. Text Elephant Seal Elephant Seals Mirounga leonina Southern Elephant Seal Southern Elephant Seals PubMed Central (PMC) Proceedings of the Royal Society B: Biological Sciences 273 1603 2901 2907 |
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Research Article Lewis, Rebecca O'Connell, Tamsin C Lewis, Mirtha Campagna, Claudio Hoelzel, A. Rus Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina) |
topic_facet |
Research Article |
description |
The evolution of resource specializations is poorly understood, especially in marine systems. The southern elephant seal (Mirounga leonina) is the largest of the phocid seals, sexually dimorphic, and thought to prey predominantly on fish and squid. We collected vibrissae from male and female southern elephant seals, and assessed stable C and N isotope ratios along the length of the vibrissae. Given that whiskers grow slowly, this sampling strategy reflects any variation in feeding behaviour over a period of time. We found that isotopic variation among females was relatively small, and that the apparent prey choice and trophic level of females was different from that for males. Further, males showed a very broad range of trophic/prey choice positions, grouped into several clusters, and this included isotopic values too low to match a broad range of potential fish and cephalopod prey tested. One of these clusters overlapped with data for South American sea lions (Otaria flavescens), which were measured for comparison. Both male southern elephant seals and southern sea lions forage over the continental shelf, providing the potential for competition. We discuss the possibility that individual southern elephant seals are pursuing specialist foraging strategies to avoid competition, both with one another, and with the South American sea lions that breed nearby. |
format |
Text |
author |
Lewis, Rebecca O'Connell, Tamsin C Lewis, Mirtha Campagna, Claudio Hoelzel, A. Rus |
author_facet |
Lewis, Rebecca O'Connell, Tamsin C Lewis, Mirtha Campagna, Claudio Hoelzel, A. Rus |
author_sort |
Lewis, Rebecca |
title |
Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina) |
title_short |
Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina) |
title_full |
Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina) |
title_fullStr |
Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina) |
title_full_unstemmed |
Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina) |
title_sort |
sex-specific foraging strategies and resource partitioning in the southern elephant seal (mirounga leonina) |
publisher |
The Royal Society |
publishDate |
2006 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1664629 http://www.ncbi.nlm.nih.gov/pubmed/17015314 https://doi.org/10.1098/rspb.2006.3642 |
genre |
Elephant Seal Elephant Seals Mirounga leonina Southern Elephant Seal Southern Elephant Seals |
genre_facet |
Elephant Seal Elephant Seals Mirounga leonina Southern Elephant Seal Southern Elephant Seals |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1664629 http://www.ncbi.nlm.nih.gov/pubmed/17015314 http://dx.doi.org/10.1098/rspb.2006.3642 |
op_rights |
© 2006 The Royal Society |
op_doi |
https://doi.org/10.1098/rspb.2006.3642 |
container_title |
Proceedings of the Royal Society B: Biological Sciences |
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273 |
container_issue |
1603 |
container_start_page |
2901 |
op_container_end_page |
2907 |
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1766401118285332480 |