Functional classification of harbor seal ( Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success
Time-depth-speed recorders and stomach-temperature sensors were deployed on 11 harbor seals (Phoca vitulina) in the St. Lawrence estuary to examine their diving and foraging behavior. Fifty-four percent of dives were to depths of <4 m. Dives that were [Formula: see text] 4 m deep were classified...
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Online Access: | http://dx.doi.org/10.1139/z98-199 http://www.nrcresearchpress.com/doi/pdf/10.1139/z98-199 |
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crcansciencepubl:10.1139/z98-199 2024-06-23T07:53:30+00:00 Functional classification of harbor seal ( Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success Lesage, Véronique Hammill, Mike O Kovacs, Kit M 1999 http://dx.doi.org/10.1139/z98-199 http://www.nrcresearchpress.com/doi/pdf/10.1139/z98-199 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 77, issue 1, page 74-87 ISSN 0008-4301 1480-3283 journal-article 1999 crcansciencepubl https://doi.org/10.1139/z98-199 2024-06-06T04:11:18Z Time-depth-speed recorders and stomach-temperature sensors were deployed on 11 harbor seals (Phoca vitulina) in the St. Lawrence estuary to examine their diving and foraging behavior. Fifty-four percent of dives were to depths of <4 m. Dives that were [Formula: see text] 4 m deep were classified into five distinct types, using a combination of principal components analysis and hierarchical and nonhierarchical clustering analyses. Feeding, indicated by a sharp decline in stomach temperature, occurred during dives of all five types, four of which were U-shaped, while one was V-shaped. Seals swam at speeds near the minimum cost of transport (MCT) during descents and ascents. V-shaped dives had mean depths of 5.8 m, lasted an average of 40 s, and often preceded or followed periods of shallow-water (<4 m) activity. Seals invariably dove to the bottom when performing U-shaped dives. These dives were to an average depth of 20 m during daylight and occurred in shallower waters (~8 m) at twilight and during the night. Once on the bottom, seals (i) swam at MCT speeds with occasional bursts of speed, (ii) swam at speeds near MCT but not exceeding it, or (iii) remained stationary or swam slowly at about 0.15 m/s, occasionally swimming faster. It is unlikely that all dives to depths [Formula: see text] 4 m are dedicated to foraging. However, the temporal segregation of dive types suggests that all types are used during foraging, although they may represent different strategies. Article in Journal/Newspaper harbor seal Phoca vitulina Canadian Science Publishing Canadian Journal of Zoology 77 1 74 87 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
Time-depth-speed recorders and stomach-temperature sensors were deployed on 11 harbor seals (Phoca vitulina) in the St. Lawrence estuary to examine their diving and foraging behavior. Fifty-four percent of dives were to depths of <4 m. Dives that were [Formula: see text] 4 m deep were classified into five distinct types, using a combination of principal components analysis and hierarchical and nonhierarchical clustering analyses. Feeding, indicated by a sharp decline in stomach temperature, occurred during dives of all five types, four of which were U-shaped, while one was V-shaped. Seals swam at speeds near the minimum cost of transport (MCT) during descents and ascents. V-shaped dives had mean depths of 5.8 m, lasted an average of 40 s, and often preceded or followed periods of shallow-water (<4 m) activity. Seals invariably dove to the bottom when performing U-shaped dives. These dives were to an average depth of 20 m during daylight and occurred in shallower waters (~8 m) at twilight and during the night. Once on the bottom, seals (i) swam at MCT speeds with occasional bursts of speed, (ii) swam at speeds near MCT but not exceeding it, or (iii) remained stationary or swam slowly at about 0.15 m/s, occasionally swimming faster. It is unlikely that all dives to depths [Formula: see text] 4 m are dedicated to foraging. However, the temporal segregation of dive types suggests that all types are used during foraging, although they may represent different strategies. |
format |
Article in Journal/Newspaper |
author |
Lesage, Véronique Hammill, Mike O Kovacs, Kit M |
spellingShingle |
Lesage, Véronique Hammill, Mike O Kovacs, Kit M Functional classification of harbor seal ( Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success |
author_facet |
Lesage, Véronique Hammill, Mike O Kovacs, Kit M |
author_sort |
Lesage, Véronique |
title |
Functional classification of harbor seal ( Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success |
title_short |
Functional classification of harbor seal ( Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success |
title_full |
Functional classification of harbor seal ( Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success |
title_fullStr |
Functional classification of harbor seal ( Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success |
title_full_unstemmed |
Functional classification of harbor seal ( Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success |
title_sort |
functional classification of harbor seal ( phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success |
publisher |
Canadian Science Publishing |
publishDate |
1999 |
url |
http://dx.doi.org/10.1139/z98-199 http://www.nrcresearchpress.com/doi/pdf/10.1139/z98-199 |
genre |
harbor seal Phoca vitulina |
genre_facet |
harbor seal Phoca vitulina |
op_source |
Canadian Journal of Zoology volume 77, issue 1, page 74-87 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z98-199 |
container_title |
Canadian Journal of Zoology |
container_volume |
77 |
container_issue |
1 |
container_start_page |
74 |
op_container_end_page |
87 |
_version_ |
1802645192451293184 |