Linking Foraging Behaviour of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales
Published by and copyright by Inter Research. The definitive version of this article is available at: http://www.int-res.com/articles/meps2007/346/m346p265.pdf ABSTRACT: We examined the foraging behaviour of 12 adult female northern elephant seals in relation to mesoscale oceanographic features betw...
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ftcalifstateuniv:oai:dspace.calstate.edu:10211.3/122663 2023-05-15T16:05:24+02:00 Linking Foraging Behaviour of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales Simmons, S.E. Crocker, Daniel E. Kudela, R.M. Costa, D.P. Crocker, Daniel E. 2007-09 http://hdl.handle.net/10211.3/122663 en_US eng Marine Ecology Progress Series http://www.int-res.com/articles/meps2007/346/m346p265.pdf Marine Ecology Progress Series Simmons, S.E., Crocker, D.E., Kudela, R.M., Costa, D.P. 2007. "Linking Foraging Behavior of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales". Marine Ecology Progress Series Vol.346 (2007) 265-275. 0171-8630 http://hdl.handle.net/10211.3/122663 Copyright of Inter Research Mirounga angustirostris temperature benthic mesoscale eddies sex Article 2007 ftcalifstateuniv 2022-04-13T11:12:56Z Published by and copyright by Inter Research. The definitive version of this article is available at: http://www.int-res.com/articles/meps2007/346/m346p265.pdf ABSTRACT: We examined the foraging behaviour of 12 adult female northern elephant seals in relation to mesoscale oceanographic features between 1995 and 1997. Females were divided into 3 groups based on the geographic region to which they migrated (???coastal???, ???coastal-oceanic??? and ???oceanic???). We defined focal foraging areas (FFAs) using satellite telemetry and average daily transit rates of ???0.4 m s???1, and examined characteristics of FFAs with respect to sea surface temperature (SST), sea surface temperature gradient (SSTg), sea level anomaly (SLA) and bathymetry using logistic regression models. Shallow bathymetry was significant for the coastal grouping of females and we examined the prevalence of benthic dives using a dive index ratio (DI), calculated by dividing mean maximum dive depth (m) by ocean depth (m) at each location for all 12 females. An additional 6 adult males were included in this analysis to quantify and elucidate differences in benthic foraging mode between the sexes. DI comparisons revealed significantly greater prevalence of benthic diving in FFAs in males than females (??2 = 10.588, p < 0.01). However, one coastal female did show a higher occurrence of benthic dives in FFAs than other females, and had significantly greater rates of mass gain. The importance of each oceanographic variable differed between the 3 groups of females. Overall, model results showed SST to be the most influential factor related to FFAs. Additionally, 6 females had FFAs that were characterised by greater SSTg and higher SLA. These characteristics are consistent with anti-cyclonic eddies that occur throughout the range of elephant seals. Semi-permanent eddies, such as the Haida and Sitka eddies of the Alaska gyre, may be particularly important in determining FFAs for some female northern elephant seals. Article in Journal/Newspaper Elephant Seal Elephant Seals Alaska California State University (CSU): DSpace |
institution |
Open Polar |
collection |
California State University (CSU): DSpace |
op_collection_id |
ftcalifstateuniv |
language |
English |
topic |
Mirounga angustirostris temperature benthic mesoscale eddies sex |
spellingShingle |
Mirounga angustirostris temperature benthic mesoscale eddies sex Simmons, S.E. Crocker, Daniel E. Kudela, R.M. Costa, D.P. Linking Foraging Behaviour of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales |
topic_facet |
Mirounga angustirostris temperature benthic mesoscale eddies sex |
description |
Published by and copyright by Inter Research. The definitive version of this article is available at: http://www.int-res.com/articles/meps2007/346/m346p265.pdf ABSTRACT: We examined the foraging behaviour of 12 adult female northern elephant seals in relation to mesoscale oceanographic features between 1995 and 1997. Females were divided into 3 groups based on the geographic region to which they migrated (???coastal???, ???coastal-oceanic??? and ???oceanic???). We defined focal foraging areas (FFAs) using satellite telemetry and average daily transit rates of ???0.4 m s???1, and examined characteristics of FFAs with respect to sea surface temperature (SST), sea surface temperature gradient (SSTg), sea level anomaly (SLA) and bathymetry using logistic regression models. Shallow bathymetry was significant for the coastal grouping of females and we examined the prevalence of benthic dives using a dive index ratio (DI), calculated by dividing mean maximum dive depth (m) by ocean depth (m) at each location for all 12 females. An additional 6 adult males were included in this analysis to quantify and elucidate differences in benthic foraging mode between the sexes. DI comparisons revealed significantly greater prevalence of benthic diving in FFAs in males than females (??2 = 10.588, p < 0.01). However, one coastal female did show a higher occurrence of benthic dives in FFAs than other females, and had significantly greater rates of mass gain. The importance of each oceanographic variable differed between the 3 groups of females. Overall, model results showed SST to be the most influential factor related to FFAs. Additionally, 6 females had FFAs that were characterised by greater SSTg and higher SLA. These characteristics are consistent with anti-cyclonic eddies that occur throughout the range of elephant seals. Semi-permanent eddies, such as the Haida and Sitka eddies of the Alaska gyre, may be particularly important in determining FFAs for some female northern elephant seals. |
author2 |
Crocker, Daniel E. |
format |
Article in Journal/Newspaper |
author |
Simmons, S.E. Crocker, Daniel E. Kudela, R.M. Costa, D.P. |
author_facet |
Simmons, S.E. Crocker, Daniel E. Kudela, R.M. Costa, D.P. |
author_sort |
Simmons, S.E. |
title |
Linking Foraging Behaviour of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales |
title_short |
Linking Foraging Behaviour of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales |
title_full |
Linking Foraging Behaviour of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales |
title_fullStr |
Linking Foraging Behaviour of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales |
title_full_unstemmed |
Linking Foraging Behaviour of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales |
title_sort |
linking foraging behaviour of the northern elephant seal with oceanography and bathymetry at mesoscales |
publisher |
Marine Ecology Progress Series |
publishDate |
2007 |
url |
http://hdl.handle.net/10211.3/122663 |
genre |
Elephant Seal Elephant Seals Alaska |
genre_facet |
Elephant Seal Elephant Seals Alaska |
op_relation |
http://www.int-res.com/articles/meps2007/346/m346p265.pdf Marine Ecology Progress Series Simmons, S.E., Crocker, D.E., Kudela, R.M., Costa, D.P. 2007. "Linking Foraging Behavior of the Northern Elephant Seal with Oceanography and Bathymetry at Mesoscales". Marine Ecology Progress Series Vol.346 (2007) 265-275. 0171-8630 http://hdl.handle.net/10211.3/122663 |
op_rights |
Copyright of Inter Research |
_version_ |
1766401290858921984 |