Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range
The Southern Hudson Bay polar bear (Ursus maritimus Phipps, 1774) subpopulation is considered stable, but conflicting evidence lends uncertainty to that designation. Capture–recapture studies conducted in 1984–1986 and 2003–2005 and an aerial survey conducted in 2011/2012 suggested that abundance wa...
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Canadian Science Publishing
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ftdoajarticles:oai:doaj.org/article:6827968cc1d6405aa43f2305ff416957 2023-05-15T14:23:39+02:00 Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range Martyn E. Obbard Seth Stapleton Guillaume Szor Kevin R. Middel Charles Jutras Markus Dyck 2018-12-01T00:00:00Z https://doi.org/10.1139/as-2018-0004 https://doaj.org/article/6827968cc1d6405aa43f2305ff416957 EN FR eng fre Canadian Science Publishing https://doi.org/10.1139/as-2018-0004 https://doaj.org/toc/2368-7460 doi:10.1139/as-2018-0004 2368-7460 https://doaj.org/article/6827968cc1d6405aa43f2305ff416957 Arctic Science, Vol 4, Iss 4, Pp 634-655 (2018) abundance estimation aerial survey mark–recapture distance-sampling polar bear southern hudson bay Environmental sciences GE1-350 Environmental engineering TA170-171 article 2018 ftdoajarticles https://doi.org/10.1139/as-2018-0004 2022-12-31T12:14:26Z The Southern Hudson Bay polar bear (Ursus maritimus Phipps, 1774) subpopulation is considered stable, but conflicting evidence lends uncertainty to that designation. Capture–recapture studies conducted in 1984–1986 and 2003–2005 and an aerial survey conducted in 2011/2012 suggested that abundance was likely unchanged since the mid-1980s. However, body condition and body size declined since then, and duration of sea ice decreased by about 30 days. Due to the conflicting information on subpopulation status and ongoing changes in sea ice, we conducted another aerial survey in 2016 to determine whether abundance had changed. We collected data via mark–recapture distance sampling and double-observer protocols. Results suggest that abundance declined 17% from 943 bears (95% CI: 658–1350) in 2011/2012 to 780 (95% CI: 590–1029) in 2016. The proportion of yearlings declined from 12% of the population in 2011 to 5% in 2016, whereas the proportion of cubs remained similar (16% in 2011 vs. 19% in 2016) suggesting low survival of the 2015 cohort. In a warming Arctic, duration of sea ice is predicted to continue to decline in Hudson Bay affecting all ice-dependent wildlife; therefore, further monitoring of this subpopulation is warranted. We recommend a conservative approach to harvest management and repeating the aerial survey in 2021. Article in Journal/Newspaper Arctic Arctic Climate change Hudson Bay Sea ice Ursus maritimus Directory of Open Access Journals: DOAJ Articles Arctic Hudson Bay Hudson Arctic Science 4 4 634 655 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English French |
topic |
abundance estimation aerial survey mark–recapture distance-sampling polar bear southern hudson bay Environmental sciences GE1-350 Environmental engineering TA170-171 |
spellingShingle |
abundance estimation aerial survey mark–recapture distance-sampling polar bear southern hudson bay Environmental sciences GE1-350 Environmental engineering TA170-171 Martyn E. Obbard Seth Stapleton Guillaume Szor Kevin R. Middel Charles Jutras Markus Dyck Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range |
topic_facet |
abundance estimation aerial survey mark–recapture distance-sampling polar bear southern hudson bay Environmental sciences GE1-350 Environmental engineering TA170-171 |
description |
The Southern Hudson Bay polar bear (Ursus maritimus Phipps, 1774) subpopulation is considered stable, but conflicting evidence lends uncertainty to that designation. Capture–recapture studies conducted in 1984–1986 and 2003–2005 and an aerial survey conducted in 2011/2012 suggested that abundance was likely unchanged since the mid-1980s. However, body condition and body size declined since then, and duration of sea ice decreased by about 30 days. Due to the conflicting information on subpopulation status and ongoing changes in sea ice, we conducted another aerial survey in 2016 to determine whether abundance had changed. We collected data via mark–recapture distance sampling and double-observer protocols. Results suggest that abundance declined 17% from 943 bears (95% CI: 658–1350) in 2011/2012 to 780 (95% CI: 590–1029) in 2016. The proportion of yearlings declined from 12% of the population in 2011 to 5% in 2016, whereas the proportion of cubs remained similar (16% in 2011 vs. 19% in 2016) suggesting low survival of the 2015 cohort. In a warming Arctic, duration of sea ice is predicted to continue to decline in Hudson Bay affecting all ice-dependent wildlife; therefore, further monitoring of this subpopulation is warranted. We recommend a conservative approach to harvest management and repeating the aerial survey in 2021. |
format |
Article in Journal/Newspaper |
author |
Martyn E. Obbard Seth Stapleton Guillaume Szor Kevin R. Middel Charles Jutras Markus Dyck |
author_facet |
Martyn E. Obbard Seth Stapleton Guillaume Szor Kevin R. Middel Charles Jutras Markus Dyck |
author_sort |
Martyn E. Obbard |
title |
Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range |
title_short |
Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range |
title_full |
Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range |
title_fullStr |
Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range |
title_full_unstemmed |
Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range |
title_sort |
re-assessing abundance of southern hudson bay polar bears by aerial survey: effects of climate change at the southern edge of the range |
publisher |
Canadian Science Publishing |
publishDate |
2018 |
url |
https://doi.org/10.1139/as-2018-0004 https://doaj.org/article/6827968cc1d6405aa43f2305ff416957 |
geographic |
Arctic Hudson Bay Hudson |
geographic_facet |
Arctic Hudson Bay Hudson |
genre |
Arctic Arctic Climate change Hudson Bay Sea ice Ursus maritimus |
genre_facet |
Arctic Arctic Climate change Hudson Bay Sea ice Ursus maritimus |
op_source |
Arctic Science, Vol 4, Iss 4, Pp 634-655 (2018) |
op_relation |
https://doi.org/10.1139/as-2018-0004 https://doaj.org/toc/2368-7460 doi:10.1139/as-2018-0004 2368-7460 https://doaj.org/article/6827968cc1d6405aa43f2305ff416957 |
op_doi |
https://doi.org/10.1139/as-2018-0004 |
container_title |
Arctic Science |
container_volume |
4 |
container_issue |
4 |
container_start_page |
634 |
op_container_end_page |
655 |
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1766296143643279360 |