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Fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird

Unlike migratory seabirds with wide foraging ranges, resident seabirds forage in a relatively small range year-round and are thus particularly vulnerable to local shifts in prey availability. In order to manage their populations effectively, it is necessary to identify their key prey across and with...

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Autores principales: Kowalczyk, Nicole D., Chiaradia, André, Preston, Tiana J., Reina, Richard D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society Publishing 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4448858/
https://www.ncbi.nlm.nih.gov/pubmed/26064628
http://dx.doi.org/10.1098/rsos.140291
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author Kowalczyk, Nicole D.
Chiaradia, André
Preston, Tiana J.
Reina, Richard D.
author_facet Kowalczyk, Nicole D.
Chiaradia, André
Preston, Tiana J.
Reina, Richard D.
author_sort Kowalczyk, Nicole D.
collection PubMed
description Unlike migratory seabirds with wide foraging ranges, resident seabirds forage in a relatively small range year-round and are thus particularly vulnerable to local shifts in prey availability. In order to manage their populations effectively, it is necessary to identify their key prey across and within years. Here, stomach content and stable isotope analyses were used to reconstruct the diet and isotopic niche of the little penguin (Eudyptula minor). Across years, the diet of penguins was dominated by anchovy (Engraulis australis). Within years, during winter, penguins were consistently enriched in δ(15)N and δ(13)C levels relative to pre-moult penguins. This was probably due to their increased reliance on juvenile anchovies, which dominate prey biomass in winter months. Following winter and during breeding, the δ(13)C values of penguins declined. We suggest this subtle shift was in response to the increased consumption of prey that enter the bay from offshore regions to spawn. Our findings highlight that penguins have access to both juvenile fish communities and spawning migrants across the year, enabling these seabirds to remain in close proximity to their colony. However, annual fluctuations in penguin isotopic niche suggest that the recruitment success and abundance of fish communities fluctuate dramatically between years. As such, the continued monitoring of penguin diet will be central to their ongoing management.
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spelling pubmed-44488582015-06-10 Fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird Kowalczyk, Nicole D. Chiaradia, André Preston, Tiana J. Reina, Richard D. R Soc Open Sci Biology (Whole Organism) Unlike migratory seabirds with wide foraging ranges, resident seabirds forage in a relatively small range year-round and are thus particularly vulnerable to local shifts in prey availability. In order to manage their populations effectively, it is necessary to identify their key prey across and within years. Here, stomach content and stable isotope analyses were used to reconstruct the diet and isotopic niche of the little penguin (Eudyptula minor). Across years, the diet of penguins was dominated by anchovy (Engraulis australis). Within years, during winter, penguins were consistently enriched in δ(15)N and δ(13)C levels relative to pre-moult penguins. This was probably due to their increased reliance on juvenile anchovies, which dominate prey biomass in winter months. Following winter and during breeding, the δ(13)C values of penguins declined. We suggest this subtle shift was in response to the increased consumption of prey that enter the bay from offshore regions to spawn. Our findings highlight that penguins have access to both juvenile fish communities and spawning migrants across the year, enabling these seabirds to remain in close proximity to their colony. However, annual fluctuations in penguin isotopic niche suggest that the recruitment success and abundance of fish communities fluctuate dramatically between years. As such, the continued monitoring of penguin diet will be central to their ongoing management. The Royal Society Publishing 2015-04-08 /pmc/articles/PMC4448858/ /pubmed/26064628 http://dx.doi.org/10.1098/rsos.140291 Text en © 2015 The Authors. http://creativecommons.org/licenses/by/4.0/ © 2015 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Biology (Whole Organism)
Kowalczyk, Nicole D.
Chiaradia, André
Preston, Tiana J.
Reina, Richard D.
Fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird
title Fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird
title_full Fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird
title_fullStr Fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird
title_full_unstemmed Fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird
title_short Fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird
title_sort fine-scale dietary changes between the breeding and non-breeding diet of a resident seabird
topic Biology (Whole Organism)
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4448858/
https://www.ncbi.nlm.nih.gov/pubmed/26064628
http://dx.doi.org/10.1098/rsos.140291
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