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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ftoslouniv:oai:www.duo.uio.no:10852/93223 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 Marie Goh, Tiffany Kuningas, Sanna Similä, Tiu Vongraven, Dag Karoliussen, Richard Bisther, Anna Hammond, Philip S. 2021-11-26T17:53:00Z http://hdl.handle.net/10852/93223 http://urn.nb.no/URN:NBN:no-95800 https://doi.org/10.1002/ece3.8364 EN eng http://urn.nb.no/URN:NBN:no-95800 Jourdain, Eve Marie 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. Ecology and Evolution. 2021, 11, 17289-17306 http://hdl.handle.net/10852/93223 1959999 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Ecology and Evolution&rft.volume=11&rft.spage=17289&rft.date=2021 Ecology and Evolution 11 23 17289 17306 https://doi.org/10.1002/ece3.8364 URN:NBN:no-95800 Fulltext https://www.duo.uio.no/bitstream/handle/10852/93223/1/Ecology%2Band%2BEvolution%2B-%2B2021%2B-%2BJourdain%2B-%2BKiller%2Bwhale%2B%2BOrcinus%2Borca%2B%2Bpopulation%2Bdynamics%2Bin%2Bresponse%2Bto%2Ba%2Bperiod%2Bof%2Brapid.pdf Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ CC-BY 2045-7758 VDP::Marinbiologi: 497VDP::Økologi: 488 Journal article Tidsskriftartikkel Peer reviewed PublishedVersion 2021 ftoslouniv https://doi.org/10.1002/ece3.8364 2022-04-06T22:33:50Z 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. Article in Journal/Newspaper Killer Whale North Atlantic Orca Orcinus orca Killer whale Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Norway Ecology and Evolution 11 23 17289 17306 |
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Open Polar |
collection |
Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
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ftoslouniv |
language |
English |
topic |
VDP::Marinbiologi: 497VDP::Økologi: 488 |
spellingShingle |
VDP::Marinbiologi: 497VDP::Økologi: 488 Jourdain, Eve Marie 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 |
topic_facet |
VDP::Marinbiologi: 497VDP::Økologi: 488 |
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 |
Article in Journal/Newspaper |
author |
Jourdain, Eve Marie Goh, Tiffany Kuningas, Sanna Similä, Tiu Vongraven, Dag Karoliussen, Richard Bisther, Anna Hammond, Philip S. |
author_facet |
Jourdain, Eve Marie Goh, Tiffany Kuningas, Sanna Similä, Tiu Vongraven, Dag Karoliussen, Richard Bisther, Anna Hammond, Philip S. |
author_sort |
Jourdain, Eve Marie |
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 |
publishDate |
2021 |
url |
http://hdl.handle.net/10852/93223 http://urn.nb.no/URN:NBN:no-95800 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 |
2045-7758 |
op_relation |
http://urn.nb.no/URN:NBN:no-95800 Jourdain, Eve Marie 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. Ecology and Evolution. 2021, 11, 17289-17306 http://hdl.handle.net/10852/93223 1959999 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Ecology and Evolution&rft.volume=11&rft.spage=17289&rft.date=2021 Ecology and Evolution 11 23 17289 17306 https://doi.org/10.1002/ece3.8364 URN:NBN:no-95800 Fulltext https://www.duo.uio.no/bitstream/handle/10852/93223/1/Ecology%2Band%2BEvolution%2B-%2B2021%2B-%2BJourdain%2B-%2BKiller%2Bwhale%2B%2BOrcinus%2Borca%2B%2Bpopulation%2Bdynamics%2Bin%2Bresponse%2Bto%2Ba%2Bperiod%2Bof%2Brapid.pdf |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1002/ece3.8364 |
container_title |
Ecology and Evolution |
container_volume |
11 |
container_issue |
23 |
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17289 |
op_container_end_page |
17306 |
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1766057570950184960 |