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Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity

1. Understanding interspecific interactions, and the influences of anthropogenic disturbance and environmental change on communities, are key challenges in ecology. Despite the pressing need to understand these fundamental drivers of community structure and dynamics, only 17% of ecological studies c...

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Autores principales: Moreno, Rocío, Stowasser, Gabriele, McGill, Rona A. R., Bearhop, Stuart, Phillips, Richard A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4989482/
https://www.ncbi.nlm.nih.gov/pubmed/26439671
http://dx.doi.org/10.1111/1365-2656.12434
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author Moreno, Rocío
Stowasser, Gabriele
McGill, Rona A. R.
Bearhop, Stuart
Phillips, Richard A.
author_facet Moreno, Rocío
Stowasser, Gabriele
McGill, Rona A. R.
Bearhop, Stuart
Phillips, Richard A.
author_sort Moreno, Rocío
collection PubMed
description 1. Understanding interspecific interactions, and the influences of anthropogenic disturbance and environmental change on communities, are key challenges in ecology. Despite the pressing need to understand these fundamental drivers of community structure and dynamics, only 17% of ecological studies conducted over the past three decades have been at the community level. 2. Here, we assess the trophic structure of the procellariiform community breeding at South Georgia, to identify the factors that determine foraging niches and possible temporal changes. We collected conventional diet data from 13 sympatric species between 1974 and 2002, and quantified intra‐ and inter‐guild, and annual variation in diet between and within foraging habits. In addition, we tested the reliability of stable isotope analysis (SIA) of seabird feathers collected over a 13‐year period, in relation to those of their potential prey, as a tool to assess community structure when diets are diverse and there is high spatial heterogeneity in environmental baselines. 3. Our results using conventional diet data identified a four‐guild community structure, distinguishing species that mainly feed on crustaceans; large fish and squid; a mixture of crustaceans, small fish and squid; or carrion. In total, Antarctic krill Euphausia superba represented 32%, and 14 other species a further 46% of the combined diet of all 13 predators, underlining the reliance of this community on relatively few types of prey. Annual variation in trophic segregation depended on relative prey availability; however, our data did not provide evidence of changes in guild structure associated with a suggested decline in Antarctic krill abundance over the past 40 years. 4. Reflecting the differences in δ(15) N of potential prey (crustaceans vs. squid vs. fish and carrion), analysis of δ(15) N in chick feathers identified a three‐guild community structure that was constant over a 13‐year period, but lacked the trophic cluster representing giant petrels which was identified using conventional diet data. 5. Our study is the first in recent decades to examine dietary changes in seabird communities over time. Conventional dietary analysis provided better resolution of community structure than SIA. However, δ(15) N in chick feathers, which reflected trophic (level) specialization, was nevertheless an effective and less time‐consuming means of monitoring temporal changes.
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spelling pubmed-49894822016-09-01 Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity Moreno, Rocío Stowasser, Gabriele McGill, Rona A. R. Bearhop, Stuart Phillips, Richard A. J Anim Ecol Community Ecology 1. Understanding interspecific interactions, and the influences of anthropogenic disturbance and environmental change on communities, are key challenges in ecology. Despite the pressing need to understand these fundamental drivers of community structure and dynamics, only 17% of ecological studies conducted over the past three decades have been at the community level. 2. Here, we assess the trophic structure of the procellariiform community breeding at South Georgia, to identify the factors that determine foraging niches and possible temporal changes. We collected conventional diet data from 13 sympatric species between 1974 and 2002, and quantified intra‐ and inter‐guild, and annual variation in diet between and within foraging habits. In addition, we tested the reliability of stable isotope analysis (SIA) of seabird feathers collected over a 13‐year period, in relation to those of their potential prey, as a tool to assess community structure when diets are diverse and there is high spatial heterogeneity in environmental baselines. 3. Our results using conventional diet data identified a four‐guild community structure, distinguishing species that mainly feed on crustaceans; large fish and squid; a mixture of crustaceans, small fish and squid; or carrion. In total, Antarctic krill Euphausia superba represented 32%, and 14 other species a further 46% of the combined diet of all 13 predators, underlining the reliance of this community on relatively few types of prey. Annual variation in trophic segregation depended on relative prey availability; however, our data did not provide evidence of changes in guild structure associated with a suggested decline in Antarctic krill abundance over the past 40 years. 4. Reflecting the differences in δ(15) N of potential prey (crustaceans vs. squid vs. fish and carrion), analysis of δ(15) N in chick feathers identified a three‐guild community structure that was constant over a 13‐year period, but lacked the trophic cluster representing giant petrels which was identified using conventional diet data. 5. Our study is the first in recent decades to examine dietary changes in seabird communities over time. Conventional dietary analysis provided better resolution of community structure than SIA. However, δ(15) N in chick feathers, which reflected trophic (level) specialization, was nevertheless an effective and less time‐consuming means of monitoring temporal changes. John Wiley and Sons Inc. 2015-10-06 2016-01 /pmc/articles/PMC4989482/ /pubmed/26439671 http://dx.doi.org/10.1111/1365-2656.12434 Text en © 2015 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Community Ecology
Moreno, Rocío
Stowasser, Gabriele
McGill, Rona A. R.
Bearhop, Stuart
Phillips, Richard A.
Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity
title Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity
title_full Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity
title_fullStr Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity
title_full_unstemmed Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity
title_short Assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity
title_sort assessing the structure and temporal dynamics of seabird communities: the challenge of capturing marine ecosystem complexity
topic Community Ecology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4989482/
https://www.ncbi.nlm.nih.gov/pubmed/26439671
http://dx.doi.org/10.1111/1365-2656.12434
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