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Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots
Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets Morus bassanus in relation to shelf-sea fronts. We GPS (global positioning system) tracked...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5043317/ https://www.ncbi.nlm.nih.gov/pubmed/27703698 http://dx.doi.org/10.1098/rsos.160317 |
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author | Cox, S. L. Miller, P. I. Embling, C. B. Scales, K. L. Bicknell, A. W. J. Hosegood, P. J. Morgan, G. Ingram, S. N. Votier, S. C. |
author_facet | Cox, S. L. Miller, P. I. Embling, C. B. Scales, K. L. Bicknell, A. W. J. Hosegood, P. J. Morgan, G. Ingram, S. N. Votier, S. C. |
author_sort | Cox, S. L. |
collection | PubMed |
description | Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets Morus bassanus in relation to shelf-sea fronts. We GPS (global positioning system) tracked 53 breeding birds and examined the relationship between 1901 foraging dives (from time-depth recorders) and thermal fronts (identified via Earth Observation composite front mapping) in the Celtic Sea, Northeast Atlantic. We (i) used a habitat-use availability analysis to determine whether gannets preferentially dived at fronts, and (ii) compared dive characteristics in relation to fronts to investigate the functional significance of these oceanographic features. We found that relationships between gannet dive probabilities and fronts varied by frontal metric and sex. While both sexes were more likely to dive in the presence of seasonally persistent fronts, links to more ephemeral features were less clear. Here, males were positively correlated with distance to front and cross-front gradient strength, with the reverse for females. Both sexes performed two dive strategies: shallow V-shaped plunge dives with little or no active swim phase (92% of dives) and deeper U-shaped dives with an active pursuit phase of at least 3 s (8% of dives). When foraging around fronts, gannets were half as likely to engage in U-shaped dives compared with V-shaped dives, independent of sex. Moreover, V-shaped dive durations were significantly shortened around fronts. These behavioural responses support the assertion that fronts are important foraging habitats for marine predators, and suggest a possible mechanistic link between the two in terms of dive behaviour. This research also emphasizes the importance of cross-disciplinary research when attempting to understand marine ecosystems. |
format | Online Article Text |
id | pubmed-5043317 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | The Royal Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-50433172016-10-04 Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots Cox, S. L. Miller, P. I. Embling, C. B. Scales, K. L. Bicknell, A. W. J. Hosegood, P. J. Morgan, G. Ingram, S. N. Votier, S. C. R Soc Open Sci Biology (Whole Organism) Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets Morus bassanus in relation to shelf-sea fronts. We GPS (global positioning system) tracked 53 breeding birds and examined the relationship between 1901 foraging dives (from time-depth recorders) and thermal fronts (identified via Earth Observation composite front mapping) in the Celtic Sea, Northeast Atlantic. We (i) used a habitat-use availability analysis to determine whether gannets preferentially dived at fronts, and (ii) compared dive characteristics in relation to fronts to investigate the functional significance of these oceanographic features. We found that relationships between gannet dive probabilities and fronts varied by frontal metric and sex. While both sexes were more likely to dive in the presence of seasonally persistent fronts, links to more ephemeral features were less clear. Here, males were positively correlated with distance to front and cross-front gradient strength, with the reverse for females. Both sexes performed two dive strategies: shallow V-shaped plunge dives with little or no active swim phase (92% of dives) and deeper U-shaped dives with an active pursuit phase of at least 3 s (8% of dives). When foraging around fronts, gannets were half as likely to engage in U-shaped dives compared with V-shaped dives, independent of sex. Moreover, V-shaped dive durations were significantly shortened around fronts. These behavioural responses support the assertion that fronts are important foraging habitats for marine predators, and suggest a possible mechanistic link between the two in terms of dive behaviour. This research also emphasizes the importance of cross-disciplinary research when attempting to understand marine ecosystems. The Royal Society 2016-09-21 /pmc/articles/PMC5043317/ /pubmed/27703698 http://dx.doi.org/10.1098/rsos.160317 Text en © 2016 The Authors. http://creativecommons.org/licenses/by/4.0/ 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) Cox, S. L. Miller, P. I. Embling, C. B. Scales, K. L. Bicknell, A. W. J. Hosegood, P. J. Morgan, G. Ingram, S. N. Votier, S. C. Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots |
title | Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots |
title_full | Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots |
title_fullStr | Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots |
title_full_unstemmed | Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots |
title_short | Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots |
title_sort | seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots |
topic | Biology (Whole Organism) |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5043317/ https://www.ncbi.nlm.nih.gov/pubmed/27703698 http://dx.doi.org/10.1098/rsos.160317 |
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