A New Method to Quantify within Dive Foraging Behaviour in Marine Predators
Studies on diving behaviour classically divide a dive into three phases: the descent, bottom and ascent phases, with foraging assumed to occur during the bottom phase. The greater complexity of dive revealed through modern, high resolution data highlights the need to re-assess this approach and to c...
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ftpubmed:oai:pubmedcentral.nih.gov:4055756 2023-05-15T16:05:45+02:00 A New Method to Quantify within Dive Foraging Behaviour in Marine Predators Heerah, Karine Hindell, Mark Guinet, Christophe Charrassin, Jean-Benoît 2014-06-12 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4055756 http://www.ncbi.nlm.nih.gov/pubmed/24922323 https://doi.org/10.1371/journal.pone.0099329 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC http://www.ncbi.nlm.nih.gov/pubmed/24922323 http://dx.doi.org/10.1371/journal.pone.0099329 This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY Research Article Text 2014 ftpubmed https://doi.org/10.1371/journal.pone.0099329 2014-06-22T00:57:24Z Studies on diving behaviour classically divide a dive into three phases: the descent, bottom and ascent phases, with foraging assumed to occur during the bottom phase. The greater complexity of dive revealed through modern, high resolution data highlights the need to re-assess this approach and to consider a larger number of phases within individual dives. Two southern elephant seals (SES) were fitted with a head mounted Time Depth Recorder (TDR) and an accelerometer from which prey capture attempts were estimated. A Weddell seal was also fitted with a TDR. TDRs for both species recorded depth once per second. We quantified the within dive behaviour using an automated broken stick algorithm identifying the optimal number of segments within each dive. The vertical sinuosity of the segments was used to infer two types of behaviours, with highly sinuous segments indicating "hunting" and less sinuous segments indicating "transiting". Using the broken stick method the seals alternated between "hunting" and "transit" modes with an average of 6±2 and 7±0.02 behavioural phases within each dive for the Weddell seal and SES, respectively. In SES, 77% of prey capture attempts (identified from the acceleration data) occurred in highly sinuous phases (“hunting”) as defined by our new approach. SES spent more time in transit mode within a dive, and hunting mostly occurred during the bottom phase. Conversely the Weddell seal spent more time in hunting mode which also occurred during bottom phase but occurred mostly at shallower depths. Such differences probably reflect different foraging tactics and habitat use. For both species, hunting time differs significantly from bottom time previously used as a proxy for the time spent foraging in a dive. The hunting time defined by our method therefore provides a more accurate fine-scale description of the seals' foraging behaviour. Text Elephant Seals Southern Elephant Seals Weddell Seal PubMed Central (PMC) Weddell PLoS ONE 9 6 e99329 |
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Research Article Heerah, Karine Hindell, Mark Guinet, Christophe Charrassin, Jean-Benoît A New Method to Quantify within Dive Foraging Behaviour in Marine Predators |
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Research Article |
description |
Studies on diving behaviour classically divide a dive into three phases: the descent, bottom and ascent phases, with foraging assumed to occur during the bottom phase. The greater complexity of dive revealed through modern, high resolution data highlights the need to re-assess this approach and to consider a larger number of phases within individual dives. Two southern elephant seals (SES) were fitted with a head mounted Time Depth Recorder (TDR) and an accelerometer from which prey capture attempts were estimated. A Weddell seal was also fitted with a TDR. TDRs for both species recorded depth once per second. We quantified the within dive behaviour using an automated broken stick algorithm identifying the optimal number of segments within each dive. The vertical sinuosity of the segments was used to infer two types of behaviours, with highly sinuous segments indicating "hunting" and less sinuous segments indicating "transiting". Using the broken stick method the seals alternated between "hunting" and "transit" modes with an average of 6±2 and 7±0.02 behavioural phases within each dive for the Weddell seal and SES, respectively. In SES, 77% of prey capture attempts (identified from the acceleration data) occurred in highly sinuous phases (“hunting”) as defined by our new approach. SES spent more time in transit mode within a dive, and hunting mostly occurred during the bottom phase. Conversely the Weddell seal spent more time in hunting mode which also occurred during bottom phase but occurred mostly at shallower depths. Such differences probably reflect different foraging tactics and habitat use. For both species, hunting time differs significantly from bottom time previously used as a proxy for the time spent foraging in a dive. The hunting time defined by our method therefore provides a more accurate fine-scale description of the seals' foraging behaviour. |
format |
Text |
author |
Heerah, Karine Hindell, Mark Guinet, Christophe Charrassin, Jean-Benoît |
author_facet |
Heerah, Karine Hindell, Mark Guinet, Christophe Charrassin, Jean-Benoît |
author_sort |
Heerah, Karine |
title |
A New Method to Quantify within Dive Foraging Behaviour in Marine Predators |
title_short |
A New Method to Quantify within Dive Foraging Behaviour in Marine Predators |
title_full |
A New Method to Quantify within Dive Foraging Behaviour in Marine Predators |
title_fullStr |
A New Method to Quantify within Dive Foraging Behaviour in Marine Predators |
title_full_unstemmed |
A New Method to Quantify within Dive Foraging Behaviour in Marine Predators |
title_sort |
new method to quantify within dive foraging behaviour in marine predators |
publisher |
Public Library of Science |
publishDate |
2014 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4055756 http://www.ncbi.nlm.nih.gov/pubmed/24922323 https://doi.org/10.1371/journal.pone.0099329 |
geographic |
Weddell |
geographic_facet |
Weddell |
genre |
Elephant Seals Southern Elephant Seals Weddell Seal |
genre_facet |
Elephant Seals Southern Elephant Seals Weddell Seal |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC http://www.ncbi.nlm.nih.gov/pubmed/24922323 http://dx.doi.org/10.1371/journal.pone.0099329 |
op_rights |
This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1371/journal.pone.0099329 |
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PLoS ONE |
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9 |
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6 |
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e99329 |
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