Dietary divergence is associated with increased intra-specific competition in a marine predator
Optimal foraging theory predicts that when food is plentiful all individuals should take a small range of preferred prey types, but as competition increases less preferred prey will be included in the diet. This dietary switching may not be uniform among individuals, which produces discrete dietary...
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Online Access: | http://nora.nerc.ac.uk/id/eprint/519868/ https://nora.nerc.ac.uk/id/eprint/519868/1/Ratcliffe.pdf https://www.nature.com/articles/s41598-018-25318-7 |
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ftnerc:oai:nora.nerc.ac.uk:519868 2023-05-15T15:44:42+02:00 Dietary divergence is associated with increased intra-specific competition in a marine predator Ratcliffe, Norman Adlard, Stacey Stowasser, Gabriele McGill, Rona 2018-05-01 text http://nora.nerc.ac.uk/id/eprint/519868/ https://nora.nerc.ac.uk/id/eprint/519868/1/Ratcliffe.pdf https://www.nature.com/articles/s41598-018-25318-7 en eng Springer https://nora.nerc.ac.uk/id/eprint/519868/1/Ratcliffe.pdf Ratcliffe, Norman orcid:0000-0002-3375-2431 Adlard, Stacey; Stowasser, Gabriele orcid:0000-0002-0595-0772 McGill, Rona. 2018 Dietary divergence is associated with increased intra-specific competition in a marine predator. Scientific Reports, 8, 6827. 10, pp. https://doi.org/10.1038/s41598-018-25318-7 <https://doi.org/10.1038/s41598-018-25318-7> cc_by_4 CC-BY Publication - Article PeerReviewed 2018 ftnerc https://doi.org/10.1038/s41598-018-25318-7 2023-02-04T19:46:28Z Optimal foraging theory predicts that when food is plentiful all individuals should take a small range of preferred prey types, but as competition increases less preferred prey will be included in the diet. This dietary switching may not be uniform among individuals, which produces discrete dietary clusters. We tested this hypothesis for gentoo penguins at Bird Island, South Georgia, using stable isotope analysis and biologging. Competition, in the form of the density of foraging dives, increased markedly from incubation to chick-rearing owing to increased foraging effort. Birds responded behaviourally by exploiting a greater portion of the available foraging radius and increasing dive depths. Dietary niche width doubled and two discrete dietary clusters appeared; one comprising birds that consumed mostly krill and another that ate a greater proportion of demersal fish. There were no differences in morphology between the dietary classes, but birds in the fish class had a tendency to dive deeper, which suggests a behavioural basis for specialization. Our findings are consistent with the hypothesis that intra-specific competition expands the population’s dietary niche width and drives divergence in diets among individuals. Article in Journal/Newspaper Bird Island Natural Environment Research Council: NERC Open Research Archive Bird Island ENVELOPE(-38.060,-38.060,-54.004,-54.004) Scientific Reports 8 1 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
English |
description |
Optimal foraging theory predicts that when food is plentiful all individuals should take a small range of preferred prey types, but as competition increases less preferred prey will be included in the diet. This dietary switching may not be uniform among individuals, which produces discrete dietary clusters. We tested this hypothesis for gentoo penguins at Bird Island, South Georgia, using stable isotope analysis and biologging. Competition, in the form of the density of foraging dives, increased markedly from incubation to chick-rearing owing to increased foraging effort. Birds responded behaviourally by exploiting a greater portion of the available foraging radius and increasing dive depths. Dietary niche width doubled and two discrete dietary clusters appeared; one comprising birds that consumed mostly krill and another that ate a greater proportion of demersal fish. There were no differences in morphology between the dietary classes, but birds in the fish class had a tendency to dive deeper, which suggests a behavioural basis for specialization. Our findings are consistent with the hypothesis that intra-specific competition expands the population’s dietary niche width and drives divergence in diets among individuals. |
format |
Article in Journal/Newspaper |
author |
Ratcliffe, Norman Adlard, Stacey Stowasser, Gabriele McGill, Rona |
spellingShingle |
Ratcliffe, Norman Adlard, Stacey Stowasser, Gabriele McGill, Rona Dietary divergence is associated with increased intra-specific competition in a marine predator |
author_facet |
Ratcliffe, Norman Adlard, Stacey Stowasser, Gabriele McGill, Rona |
author_sort |
Ratcliffe, Norman |
title |
Dietary divergence is associated with increased intra-specific competition in a marine predator |
title_short |
Dietary divergence is associated with increased intra-specific competition in a marine predator |
title_full |
Dietary divergence is associated with increased intra-specific competition in a marine predator |
title_fullStr |
Dietary divergence is associated with increased intra-specific competition in a marine predator |
title_full_unstemmed |
Dietary divergence is associated with increased intra-specific competition in a marine predator |
title_sort |
dietary divergence is associated with increased intra-specific competition in a marine predator |
publisher |
Springer |
publishDate |
2018 |
url |
http://nora.nerc.ac.uk/id/eprint/519868/ https://nora.nerc.ac.uk/id/eprint/519868/1/Ratcliffe.pdf https://www.nature.com/articles/s41598-018-25318-7 |
long_lat |
ENVELOPE(-38.060,-38.060,-54.004,-54.004) |
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Bird Island |
geographic_facet |
Bird Island |
genre |
Bird Island |
genre_facet |
Bird Island |
op_relation |
https://nora.nerc.ac.uk/id/eprint/519868/1/Ratcliffe.pdf Ratcliffe, Norman orcid:0000-0002-3375-2431 Adlard, Stacey; Stowasser, Gabriele orcid:0000-0002-0595-0772 McGill, Rona. 2018 Dietary divergence is associated with increased intra-specific competition in a marine predator. Scientific Reports, 8, 6827. 10, pp. https://doi.org/10.1038/s41598-018-25318-7 <https://doi.org/10.1038/s41598-018-25318-7> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1038/s41598-018-25318-7 |
container_title |
Scientific Reports |
container_volume |
8 |
container_issue |
1 |
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1766379075533799424 |