Estimating seasonal abundance of a central place forager using counts and telemetry data
Obtaining population estimates of species that are not easily observed directly can be problematic. However, central place foragers can often be observed some of the time, e.g. when seals are hauled out. In these instances, population estimates can be derived from counts, combined with information o...
Published in: | Marine Ecology Progress Series |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2009
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Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/estimating-seasonal-abundance-of-a-central-place-forager-using-counts-and-telemetry-data(4f0e29cb-76ea-4048-ba3f-0162560fea7b).html https://doi.org/10.3354/meps07827 https://research-repository.st-andrews.ac.uk/bitstream/10023/3454/1/Sharples2009MarEcolProgSer378p289.pdf http://www.scopus.com/inward/record.url?scp=63649128883&partnerID=8YFLogxK |
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/4f0e29cb-76ea-4048-ba3f-0162560fea7b 2023-05-15T16:33:36+02:00 Estimating seasonal abundance of a central place forager using counts and telemetry data Sharples, RJ MacKenzie, Monique Lea Hammond, Philip Steven 2009 application/pdf https://risweb.st-andrews.ac.uk/portal/en/researchoutput/estimating-seasonal-abundance-of-a-central-place-forager-using-counts-and-telemetry-data(4f0e29cb-76ea-4048-ba3f-0162560fea7b).html https://doi.org/10.3354/meps07827 https://research-repository.st-andrews.ac.uk/bitstream/10023/3454/1/Sharples2009MarEcolProgSer378p289.pdf http://www.scopus.com/inward/record.url?scp=63649128883&partnerID=8YFLogxK eng eng info:eu-repo/semantics/openAccess Sharples , RJ , MacKenzie , M L & Hammond , P S 2009 , ' Estimating seasonal abundance of a central place forager using counts and telemetry data ' , Marine Ecology Progress Series , vol. 378 , pp. 289-298 . https://doi.org/10.3354/meps07827 Mixed effects models Phoca vitulina Population size Autocorrelation Harbour seal Haul-out behaviour Central place forager Seals phoca-vitulina Harbor seals Gray seals North-sea Population-size Common seals Fisheries Areas Competition Declines article 2009 ftunstandrewcris https://doi.org/10.3354/meps07827 2021-12-26T14:13:21Z Obtaining population estimates of species that are not easily observed directly can be problematic. However, central place foragers can often be observed some of the time, e.g. when seals are hauled out. In these instances, population estimates can be derived from counts, combined with information on the proportion of time that animals can be observed. We present a modelling framework to estimate seasonal absolute abundance using counts and information from satellite telemetry data. The method was tested on a harbour seal population in an area of southeast Scotland. Counts were made monthly, between November 2001 and June 2003, when seals were hauled out on land and were corrected for the proportion of time the seals were at sea using satellite telemetry. Harbour seals (n=25) were tagged with satellite relay data loggers between November 2001 and March 2003. To estimate the proportion of time spent hauled out, time at sea on foraging trips was modelled separately from haul-out behaviour close to haul-out sites because of the different factors affecting these processes. A generalised linear mixed model framework was developed to capture the longitudinal nature of the data and the repeated measures across individuals. Despite seasonal variability in the number of seals counted at haul-out sites, the model generated estimates of abundance, with an overall mean of 846 (95% CI: 767 to 979). The methodology shows the value of using count and telemetry data collected concurrently for estimating absolute abundance, information that is essential to assess interactions between predators, fish stocks and fisheries. Article in Journal/Newspaper harbour seal Phoca vitulina University of St Andrews: Research Portal Marine Ecology Progress Series 378 289 298 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
Mixed effects models Phoca vitulina Population size Autocorrelation Harbour seal Haul-out behaviour Central place forager Seals phoca-vitulina Harbor seals Gray seals North-sea Population-size Common seals Fisheries Areas Competition Declines |
spellingShingle |
Mixed effects models Phoca vitulina Population size Autocorrelation Harbour seal Haul-out behaviour Central place forager Seals phoca-vitulina Harbor seals Gray seals North-sea Population-size Common seals Fisheries Areas Competition Declines Sharples, RJ MacKenzie, Monique Lea Hammond, Philip Steven Estimating seasonal abundance of a central place forager using counts and telemetry data |
topic_facet |
Mixed effects models Phoca vitulina Population size Autocorrelation Harbour seal Haul-out behaviour Central place forager Seals phoca-vitulina Harbor seals Gray seals North-sea Population-size Common seals Fisheries Areas Competition Declines |
description |
Obtaining population estimates of species that are not easily observed directly can be problematic. However, central place foragers can often be observed some of the time, e.g. when seals are hauled out. In these instances, population estimates can be derived from counts, combined with information on the proportion of time that animals can be observed. We present a modelling framework to estimate seasonal absolute abundance using counts and information from satellite telemetry data. The method was tested on a harbour seal population in an area of southeast Scotland. Counts were made monthly, between November 2001 and June 2003, when seals were hauled out on land and were corrected for the proportion of time the seals were at sea using satellite telemetry. Harbour seals (n=25) were tagged with satellite relay data loggers between November 2001 and March 2003. To estimate the proportion of time spent hauled out, time at sea on foraging trips was modelled separately from haul-out behaviour close to haul-out sites because of the different factors affecting these processes. A generalised linear mixed model framework was developed to capture the longitudinal nature of the data and the repeated measures across individuals. Despite seasonal variability in the number of seals counted at haul-out sites, the model generated estimates of abundance, with an overall mean of 846 (95% CI: 767 to 979). The methodology shows the value of using count and telemetry data collected concurrently for estimating absolute abundance, information that is essential to assess interactions between predators, fish stocks and fisheries. |
format |
Article in Journal/Newspaper |
author |
Sharples, RJ MacKenzie, Monique Lea Hammond, Philip Steven |
author_facet |
Sharples, RJ MacKenzie, Monique Lea Hammond, Philip Steven |
author_sort |
Sharples, RJ |
title |
Estimating seasonal abundance of a central place forager using counts and telemetry data |
title_short |
Estimating seasonal abundance of a central place forager using counts and telemetry data |
title_full |
Estimating seasonal abundance of a central place forager using counts and telemetry data |
title_fullStr |
Estimating seasonal abundance of a central place forager using counts and telemetry data |
title_full_unstemmed |
Estimating seasonal abundance of a central place forager using counts and telemetry data |
title_sort |
estimating seasonal abundance of a central place forager using counts and telemetry data |
publishDate |
2009 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/estimating-seasonal-abundance-of-a-central-place-forager-using-counts-and-telemetry-data(4f0e29cb-76ea-4048-ba3f-0162560fea7b).html https://doi.org/10.3354/meps07827 https://research-repository.st-andrews.ac.uk/bitstream/10023/3454/1/Sharples2009MarEcolProgSer378p289.pdf http://www.scopus.com/inward/record.url?scp=63649128883&partnerID=8YFLogxK |
genre |
harbour seal Phoca vitulina |
genre_facet |
harbour seal Phoca vitulina |
op_source |
Sharples , RJ , MacKenzie , M L & Hammond , P S 2009 , ' Estimating seasonal abundance of a central place forager using counts and telemetry data ' , Marine Ecology Progress Series , vol. 378 , pp. 289-298 . https://doi.org/10.3354/meps07827 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.3354/meps07827 |
container_title |
Marine Ecology Progress Series |
container_volume |
378 |
container_start_page |
289 |
op_container_end_page |
298 |
_version_ |
1766023290016497664 |