Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials
The analysis of pinniped scats has been used to quantify their diet, using prey remains to identify species and to estimate the numbers and sizes of prey consumed. There are, however, potential biases involved with scat analysis and, for this method to be used successfully, these biases need to be q...
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Online Access: | http://nora.nerc.ac.uk/id/eprint/5991/ https://doi.org/10.1111/j.1748-7692.2002.tb01030.x |
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ftnerc:oai:nora.nerc.ac.uk:5991 2024-06-09T07:40:24+00:00 Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials Staniland, I.J. 2002 http://nora.nerc.ac.uk/id/eprint/5991/ https://doi.org/10.1111/j.1748-7692.2002.tb01030.x unknown Wiley Staniland, I.J. 2002 Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials. Marine Mammal Science, 18 (1). 223-243. https://doi.org/10.1111/j.1748-7692.2002.tb01030.x <https://doi.org/10.1111/j.1748-7692.2002.tb01030.x> Zoology Ecology and Environment Publication - Article PeerReviewed 2002 ftnerc https://doi.org/10.1111/j.1748-7692.2002.tb01030.x 2024-05-15T08:52:26Z The analysis of pinniped scats has been used to quantify their diet, using prey remains to identify species and to estimate the numbers and sizes of prey consumed. There are, however, potential biases involved with scat analysis and, for this method to be used successfully, these biases need to be quantified. Thirty-six Antarctic fur seals (Arctocephalus gazella) were fed meals of exclusively either fish, squid, or krill and their scats were collected and analyzed. The major sources of error in the analysis of prey remains from scats were the differential erosion and passage rate of items in relation to their size. However, using simple correction functions, such as those which model otolith erosion, it is possible to reduce these errors. Using plastic beads as dietary markers showed recovery rates were negatively related to their size. Larger squid beaks had lower recovery rates than smaller beaks, but there was no size-related bias in the recovery rates of krill carapaces. Only 33% of the squid beaks and 27% of the otoliths originally fed were recovered from the scats. Recovery rates were greater for squid (77%) and fish (50%) eye lenses and these structures gave a better estimate of numbers eaten. Differences found between experimentally derived and published regression equations (used to calculate prey sizes eaten from prey remains) highlights the need for regression equations based on local prey characteristics, if these are to be used with any success to describe the prey eaten. Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seals Arctocephalus gazella Natural Environment Research Council: NERC Open Research Archive Antarctic Marine Mammal Science 18 1 223 243 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Zoology Ecology and Environment |
spellingShingle |
Zoology Ecology and Environment Staniland, I.J. Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials |
topic_facet |
Zoology Ecology and Environment |
description |
The analysis of pinniped scats has been used to quantify their diet, using prey remains to identify species and to estimate the numbers and sizes of prey consumed. There are, however, potential biases involved with scat analysis and, for this method to be used successfully, these biases need to be quantified. Thirty-six Antarctic fur seals (Arctocephalus gazella) were fed meals of exclusively either fish, squid, or krill and their scats were collected and analyzed. The major sources of error in the analysis of prey remains from scats were the differential erosion and passage rate of items in relation to their size. However, using simple correction functions, such as those which model otolith erosion, it is possible to reduce these errors. Using plastic beads as dietary markers showed recovery rates were negatively related to their size. Larger squid beaks had lower recovery rates than smaller beaks, but there was no size-related bias in the recovery rates of krill carapaces. Only 33% of the squid beaks and 27% of the otoliths originally fed were recovered from the scats. Recovery rates were greater for squid (77%) and fish (50%) eye lenses and these structures gave a better estimate of numbers eaten. Differences found between experimentally derived and published regression equations (used to calculate prey sizes eaten from prey remains) highlights the need for regression equations based on local prey characteristics, if these are to be used with any success to describe the prey eaten. |
format |
Article in Journal/Newspaper |
author |
Staniland, I.J. |
author_facet |
Staniland, I.J. |
author_sort |
Staniland, I.J. |
title |
Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials |
title_short |
Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials |
title_full |
Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials |
title_fullStr |
Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials |
title_full_unstemmed |
Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials |
title_sort |
investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (arctocephalus gazella) in captive feeding trials |
publisher |
Wiley |
publishDate |
2002 |
url |
http://nora.nerc.ac.uk/id/eprint/5991/ https://doi.org/10.1111/j.1748-7692.2002.tb01030.x |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctic Fur Seals Arctocephalus gazella |
genre_facet |
Antarc* Antarctic Antarctic Fur Seals Arctocephalus gazella |
op_relation |
Staniland, I.J. 2002 Investigating the biases in the use of hard prey remains to identify diet composition using antarctic fur seals (Arctocephalus gazella) in captive feeding trials. Marine Mammal Science, 18 (1). 223-243. https://doi.org/10.1111/j.1748-7692.2002.tb01030.x <https://doi.org/10.1111/j.1748-7692.2002.tb01030.x> |
op_doi |
https://doi.org/10.1111/j.1748-7692.2002.tb01030.x |
container_title |
Marine Mammal Science |
container_volume |
18 |
container_issue |
1 |
container_start_page |
223 |
op_container_end_page |
243 |
_version_ |
1801383815264862208 |