ASSESSING KILLER WHALE PREDATION ON STELLER SEA LIONS FROM FIELD OBSERVATIONS IN KENAI FJORDS, ALASKA
Abstract The behavioral and predatory patterns of Gulf of Alaska (GOA) transient killer whales ( Orcinus orca ) were studied between 2000 and 2005 using remote video and vessel‐based observations near the Chiswell Island Steller sea lion ( Eumetopias jubatus ) rookery and in the broader Kenai Fjords...
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crwiley:10.1111/j.1748-7692.2007.00103.x 2024-09-15T18:16:42+00:00 ASSESSING KILLER WHALE PREDATION ON STELLER SEA LIONS FROM FIELD OBSERVATIONS IN KENAI FJORDS, ALASKA Maniscalco, John M. Matkin, Craig O. Maldini, Daniela Calkins, Donald G. Atkinson, Shannon 2007 http://dx.doi.org/10.1111/j.1748-7692.2007.00103.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2007.00103.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2007.00103.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Marine Mammal Science volume 23, issue 2, page 306-321 ISSN 0824-0469 1748-7692 journal-article 2007 crwiley https://doi.org/10.1111/j.1748-7692.2007.00103.x 2024-08-09T04:29:20Z Abstract The behavioral and predatory patterns of Gulf of Alaska (GOA) transient killer whales ( Orcinus orca ) were studied between 2000 and 2005 using remote video and vessel‐based observations near the Chiswell Island Steller sea lion ( Eumetopias jubatus ) rookery and in the broader Kenai Fjords (KF) region of the northern GOA. GOA transient killer whales were observed on 118 d over the 6‐yr period; the median group size was two (range: 1–9). Nine predation events were observed from vessels and an additional sixteen were inferred from remote video studies; all involved Steller sea lions. Estimates from field observations suggest that fifty‐nine sea lions were consumed over the summer seasons of 2002–2005; whereas estimates based on published caloric requirements of transient killer whales would suggest a loss of 103 sea lions over the same time period. GOA transients spent a large proportion (43%) of their time resting which may be a strategy for conserving energy. Predation on sea lion pups at the Chiswell Island rookery was greatest during years when a single killer whale was foraging alone and when a 1.5‐yr‐old calf was evidently being trained to handle prey. Predation on pups was low during years when killer whales were foraging in groups and were observed and presumed to be taking mostly juvenile sea lions. Our study suggests that GOA transients are having a minor effect on the recovery of Steller sea lions in the GOA. Article in Journal/Newspaper Killer Whale Orca Orcinus orca Alaska Killer whale Wiley Online Library Marine Mammal Science 23 2 306 321 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract The behavioral and predatory patterns of Gulf of Alaska (GOA) transient killer whales ( Orcinus orca ) were studied between 2000 and 2005 using remote video and vessel‐based observations near the Chiswell Island Steller sea lion ( Eumetopias jubatus ) rookery and in the broader Kenai Fjords (KF) region of the northern GOA. GOA transient killer whales were observed on 118 d over the 6‐yr period; the median group size was two (range: 1–9). Nine predation events were observed from vessels and an additional sixteen were inferred from remote video studies; all involved Steller sea lions. Estimates from field observations suggest that fifty‐nine sea lions were consumed over the summer seasons of 2002–2005; whereas estimates based on published caloric requirements of transient killer whales would suggest a loss of 103 sea lions over the same time period. GOA transients spent a large proportion (43%) of their time resting which may be a strategy for conserving energy. Predation on sea lion pups at the Chiswell Island rookery was greatest during years when a single killer whale was foraging alone and when a 1.5‐yr‐old calf was evidently being trained to handle prey. Predation on pups was low during years when killer whales were foraging in groups and were observed and presumed to be taking mostly juvenile sea lions. Our study suggests that GOA transients are having a minor effect on the recovery of Steller sea lions in the GOA. |
format |
Article in Journal/Newspaper |
author |
Maniscalco, John M. Matkin, Craig O. Maldini, Daniela Calkins, Donald G. Atkinson, Shannon |
spellingShingle |
Maniscalco, John M. Matkin, Craig O. Maldini, Daniela Calkins, Donald G. Atkinson, Shannon ASSESSING KILLER WHALE PREDATION ON STELLER SEA LIONS FROM FIELD OBSERVATIONS IN KENAI FJORDS, ALASKA |
author_facet |
Maniscalco, John M. Matkin, Craig O. Maldini, Daniela Calkins, Donald G. Atkinson, Shannon |
author_sort |
Maniscalco, John M. |
title |
ASSESSING KILLER WHALE PREDATION ON STELLER SEA LIONS FROM FIELD OBSERVATIONS IN KENAI FJORDS, ALASKA |
title_short |
ASSESSING KILLER WHALE PREDATION ON STELLER SEA LIONS FROM FIELD OBSERVATIONS IN KENAI FJORDS, ALASKA |
title_full |
ASSESSING KILLER WHALE PREDATION ON STELLER SEA LIONS FROM FIELD OBSERVATIONS IN KENAI FJORDS, ALASKA |
title_fullStr |
ASSESSING KILLER WHALE PREDATION ON STELLER SEA LIONS FROM FIELD OBSERVATIONS IN KENAI FJORDS, ALASKA |
title_full_unstemmed |
ASSESSING KILLER WHALE PREDATION ON STELLER SEA LIONS FROM FIELD OBSERVATIONS IN KENAI FJORDS, ALASKA |
title_sort |
assessing killer whale predation on steller sea lions from field observations in kenai fjords, alaska |
publisher |
Wiley |
publishDate |
2007 |
url |
http://dx.doi.org/10.1111/j.1748-7692.2007.00103.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2007.00103.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2007.00103.x |
genre |
Killer Whale Orca Orcinus orca Alaska Killer whale |
genre_facet |
Killer Whale Orca Orcinus orca Alaska Killer whale |
op_source |
Marine Mammal Science volume 23, issue 2, page 306-321 ISSN 0824-0469 1748-7692 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1748-7692.2007.00103.x |
container_title |
Marine Mammal Science |
container_volume |
23 |
container_issue |
2 |
container_start_page |
306 |
op_container_end_page |
321 |
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1810454718317592576 |