Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic
This study investigates survival and abundance of killer whales (Orcinus orca) in Norway in 1988–2019 using capture–recapture models of photo‐identification data. We merged two datasets collected in a restricted fjord system in 1988–2008 (Period 1) with a third, collected after their preferred herri...
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Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8668809/ http://www.ncbi.nlm.nih.gov/pubmed/34938508 https://doi.org/10.1002/ece3.8364 |
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ftpubmed:oai:pubmedcentral.nih.gov:8668809 2023-05-15T17:03:40+02:00 Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic Jourdain, Eve Goh, Tiffany Kuningas, Sanna Similä, Tiu Vongraven, Dag Karoliussen, Richard Bisther, Anna Hammond, Philip S. 2021-11-18 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8668809/ http://www.ncbi.nlm.nih.gov/pubmed/34938508 https://doi.org/10.1002/ece3.8364 en eng John Wiley and Sons Inc. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8668809/ http://www.ncbi.nlm.nih.gov/pubmed/34938508 http://dx.doi.org/10.1002/ece3.8364 © 2021 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. https://creativecommons.org/licenses/by/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. CC-BY Ecol Evol Research Articles Text 2021 ftpubmed https://doi.org/10.1002/ece3.8364 2021-12-26T01:30:27Z This study investigates survival and abundance of killer whales (Orcinus orca) in Norway in 1988–2019 using capture–recapture models of photo‐identification data. We merged two datasets collected in a restricted fjord system in 1988–2008 (Period 1) with a third, collected after their preferred herring prey shifted its wintering grounds to more exposed coastal waters in 2012–2019 (Period 2), and investigated any differences between these two periods. The resulting dataset, spanning 32 years, comprised 3284 captures of 1236 whales, including 148 individuals seen in both periods. The best‐supported models of survival included the effects of sex and time period, and the presence of transients (whales seen only once). Period 2 had a much larger percentage of transients compared to Period 1 (mean = 30% vs. 5%) and the identification of two groups of whales with different residency patterns revealed heterogeneity in recapture probabilities. This caused estimates of survival rates to be biased downward (females: 0.955 ± 0.027 SE, males: 0.864 ± 0.038 SE) compared to Period 1 (females: 0.998 ± 0.002 SE, males: 0.985 ± 0.009 SE). Accounting for this heterogeneity resulted in estimates of apparent survival close to unity for regularly seen whales in Period 2. A robust design model for Period 2 further supported random temporary emigration at an estimated annual probability of 0.148 (± 0.095 SE). This same model estimated a peak in annual abundance in 2015 at 1061 individuals (95% CI 999–1127), compared to a maximum of 731 (95% CI 505–1059) previously estimated in Period 1, and dropped to 513 (95% CI 488–540) in 2018. Our results indicate variations in the proportion of killer whales present of an undefined population (or populations) in a larger geographical region. Killer whales have adjusted their distribution to shifts in key prey resources, indicating potential to adapt to rapidly changing marine ecosystems. Text Killer Whale North Atlantic Orca Orcinus orca Killer whale PubMed Central (PMC) Norway Ecology and Evolution 11 23 17289 17306 |
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Research Articles |
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Research Articles Jourdain, Eve Goh, Tiffany Kuningas, Sanna Similä, Tiu Vongraven, Dag Karoliussen, Richard Bisther, Anna Hammond, Philip S. Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic |
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Research Articles |
description |
This study investigates survival and abundance of killer whales (Orcinus orca) in Norway in 1988–2019 using capture–recapture models of photo‐identification data. We merged two datasets collected in a restricted fjord system in 1988–2008 (Period 1) with a third, collected after their preferred herring prey shifted its wintering grounds to more exposed coastal waters in 2012–2019 (Period 2), and investigated any differences between these two periods. The resulting dataset, spanning 32 years, comprised 3284 captures of 1236 whales, including 148 individuals seen in both periods. The best‐supported models of survival included the effects of sex and time period, and the presence of transients (whales seen only once). Period 2 had a much larger percentage of transients compared to Period 1 (mean = 30% vs. 5%) and the identification of two groups of whales with different residency patterns revealed heterogeneity in recapture probabilities. This caused estimates of survival rates to be biased downward (females: 0.955 ± 0.027 SE, males: 0.864 ± 0.038 SE) compared to Period 1 (females: 0.998 ± 0.002 SE, males: 0.985 ± 0.009 SE). Accounting for this heterogeneity resulted in estimates of apparent survival close to unity for regularly seen whales in Period 2. A robust design model for Period 2 further supported random temporary emigration at an estimated annual probability of 0.148 (± 0.095 SE). This same model estimated a peak in annual abundance in 2015 at 1061 individuals (95% CI 999–1127), compared to a maximum of 731 (95% CI 505–1059) previously estimated in Period 1, and dropped to 513 (95% CI 488–540) in 2018. Our results indicate variations in the proportion of killer whales present of an undefined population (or populations) in a larger geographical region. Killer whales have adjusted their distribution to shifts in key prey resources, indicating potential to adapt to rapidly changing marine ecosystems. |
format |
Text |
author |
Jourdain, Eve Goh, Tiffany Kuningas, Sanna Similä, Tiu Vongraven, Dag Karoliussen, Richard Bisther, Anna Hammond, Philip S. |
author_facet |
Jourdain, Eve Goh, Tiffany Kuningas, Sanna Similä, Tiu Vongraven, Dag Karoliussen, Richard Bisther, Anna Hammond, Philip S. |
author_sort |
Jourdain, Eve |
title |
Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic |
title_short |
Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic |
title_full |
Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic |
title_fullStr |
Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic |
title_full_unstemmed |
Killer whale (Orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern North Atlantic |
title_sort |
killer whale (orcinus orca) population dynamics in response to a period of rapid ecosystem change in the eastern north atlantic |
publisher |
John Wiley and Sons Inc. |
publishDate |
2021 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8668809/ http://www.ncbi.nlm.nih.gov/pubmed/34938508 https://doi.org/10.1002/ece3.8364 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Killer Whale North Atlantic Orca Orcinus orca Killer whale |
genre_facet |
Killer Whale North Atlantic Orca Orcinus orca Killer whale |
op_source |
Ecol Evol |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8668809/ http://www.ncbi.nlm.nih.gov/pubmed/34938508 http://dx.doi.org/10.1002/ece3.8364 |
op_rights |
© 2021 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. https://creativecommons.org/licenses/by/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1002/ece3.8364 |
container_title |
Ecology and Evolution |
container_volume |
11 |
container_issue |
23 |
container_start_page |
17289 |
op_container_end_page |
17306 |
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1766057576164753408 |