Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040
Monitoring changes in the distribution of large carnivores is important for managing human safety and supporting conservation. Throughout much of their range, polar bears (Ursus maritimus) are increasingly using terrestrial habitats in response to Arctic sea ice decline. Their increased presence in...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-12-01
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| Series: | Global Ecology and Conservation |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2351989422003213 |
| _version_ | 1811314817900740608 |
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| author | Karyn D. Rode D.C. Douglas T.C. Atwood G.M. Durner R.R. Wilson A.M. Pagano |
| author_facet | Karyn D. Rode D.C. Douglas T.C. Atwood G.M. Durner R.R. Wilson A.M. Pagano |
| author_sort | Karyn D. Rode |
| collection | DOAJ |
| description | Monitoring changes in the distribution of large carnivores is important for managing human safety and supporting conservation. Throughout much of their range, polar bears (Ursus maritimus) are increasingly using terrestrial habitats in response to Arctic sea ice decline. Their increased presence in coastal areas has implications for bear-human conflict, inter-species interactions, and polar bear health and survival. We examined observed trends in land use over three decades by polar bears in the southern Beaufort Sea (SB) and Chukchi Sea (CS) where bears have traditionally spent most of the year on the sea ice. Using data from 408 adult females fitted with satellite radio-collars, we examined trends in the annual proportion of bears coming onshore (hereafter referred to as “percent of bears”) during the summer for ≥ 21 days, arrival and departure dates, duration spent onshore and relationships with sea ice metrics. We then estimated future land use through 2040 by extrapolating trends and by combining observed relationships between land use and sea ice with projections of future sea ice from an ensemble of earth system models. The observed percent of bears summering onshore and their duration onshore was correlated with the percent of open water that occurred within their population’s range between July and October. As sea ice declined, the percent of bears summering onshore increased from ∼5–30% in the SB and ∼10–50% in the CS and duration onshore increased by > 30 days to 60–70 days in both populations. Using a range of greenhouse gas emission scenarios and adjustments for faster than forecasted sea ice loss we estimated that 50–62% of SB and 79–88% of CS bears will spend 90–108 and 110–126 days onshore during summer in the SB and CS, respectively, by 2040. Sea ice projections varied little between greenhouse gas emission scenarios prior to 2040 but diverged thereafter. Observed and forecasted increases in polar bear land occupancy puts more bears in proximity to human activities and settlements for longer durations while extending the lack of access to their primary prey. Because human conflict is one of the primary factors affecting the conservation of large carnivores worldwide, mitigation of bear-human interactions on land will be an increasingly important component of polar bear conservation. |
| first_indexed | 2024-04-13T11:19:15Z |
| format | Article |
| id | doaj.art-c1bcd8dcddfa4a83ba5bf3d8c417bb84 |
| institution | Directory Open Access Journal |
| issn | 2351-9894 |
| language | English |
| last_indexed | 2024-04-13T11:19:15Z |
| publishDate | 2022-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Global Ecology and Conservation |
| spelling | doaj.art-c1bcd8dcddfa4a83ba5bf3d8c417bb842022-12-22T02:48:53ZengElsevierGlobal Ecology and Conservation2351-98942022-12-0140e02319Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040Karyn D. Rode0D.C. Douglas1T.C. Atwood2G.M. Durner3R.R. Wilson4A.M. Pagano5US Geological Survey, Alaska Science Center, Anchorage, AK, USA; Correspondence to: 4210 University Drive, Anchorage, AK 99508, USA.US Geological Survey, Alaska Science Center, Juneau, AK, USAUS Geological Survey, Alaska Science Center, Anchorage, AK, USAUS Geological Survey, Alaska Science Center, Anchorage, AK, USAUS Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK, USAUS Geological Survey, Alaska Science Center, Anchorage, AK, USAMonitoring changes in the distribution of large carnivores is important for managing human safety and supporting conservation. Throughout much of their range, polar bears (Ursus maritimus) are increasingly using terrestrial habitats in response to Arctic sea ice decline. Their increased presence in coastal areas has implications for bear-human conflict, inter-species interactions, and polar bear health and survival. We examined observed trends in land use over three decades by polar bears in the southern Beaufort Sea (SB) and Chukchi Sea (CS) where bears have traditionally spent most of the year on the sea ice. Using data from 408 adult females fitted with satellite radio-collars, we examined trends in the annual proportion of bears coming onshore (hereafter referred to as “percent of bears”) during the summer for ≥ 21 days, arrival and departure dates, duration spent onshore and relationships with sea ice metrics. We then estimated future land use through 2040 by extrapolating trends and by combining observed relationships between land use and sea ice with projections of future sea ice from an ensemble of earth system models. The observed percent of bears summering onshore and their duration onshore was correlated with the percent of open water that occurred within their population’s range between July and October. As sea ice declined, the percent of bears summering onshore increased from ∼5–30% in the SB and ∼10–50% in the CS and duration onshore increased by > 30 days to 60–70 days in both populations. Using a range of greenhouse gas emission scenarios and adjustments for faster than forecasted sea ice loss we estimated that 50–62% of SB and 79–88% of CS bears will spend 90–108 and 110–126 days onshore during summer in the SB and CS, respectively, by 2040. Sea ice projections varied little between greenhouse gas emission scenarios prior to 2040 but diverged thereafter. Observed and forecasted increases in polar bear land occupancy puts more bears in proximity to human activities and settlements for longer durations while extending the lack of access to their primary prey. Because human conflict is one of the primary factors affecting the conservation of large carnivores worldwide, mitigation of bear-human interactions on land will be an increasingly important component of polar bear conservation.http://www.sciencedirect.com/science/article/pii/S2351989422003213ArcticGlobal warmingHuman-wildlife conflictSea iceUrsus maritimus |
| spellingShingle | Karyn D. Rode D.C. Douglas T.C. Atwood G.M. Durner R.R. Wilson A.M. Pagano Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040 Global Ecology and Conservation Arctic Global warming Human-wildlife conflict Sea ice Ursus maritimus |
| title | Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040 |
| title_full | Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040 |
| title_fullStr | Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040 |
| title_full_unstemmed | Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040 |
| title_short | Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040 |
| title_sort | observed and forecasted changes in land use by polar bears in the beaufort and chukchi seas 1985 2040 |
| topic | Arctic Global warming Human-wildlife conflict Sea ice Ursus maritimus |
| url | http://www.sciencedirect.com/science/article/pii/S2351989422003213 |
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