Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, Canada
Climate warming and associated physical and biological changes will likely force widespread species redistribution, particularly in polar environments. However, tracking such distributional shifts is difficult. The dietary habits of apex predators, like polar bears (Ursus maritimus), may provide ear...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2021-12-01
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| Series: | Ecological Indicators |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1470160X21009109 |
| _version_ | 1818461075333447680 |
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| author | Melissa P. Galicia Gregory W. Thiemann Markus G. Dyck Steven H. Ferguson |
| author_facet | Melissa P. Galicia Gregory W. Thiemann Markus G. Dyck Steven H. Ferguson |
| author_sort | Melissa P. Galicia |
| collection | DOAJ |
| description | Climate warming and associated physical and biological changes will likely force widespread species redistribution, particularly in polar environments. However, tracking such distributional shifts is difficult. The dietary habits of apex predators, like polar bears (Ursus maritimus), may provide early signals of distributional change in prey populations. We used harvest-based sampling to investigate the spatial feeding patterns of polar bears across Nunavut from 2010 to 2018 (n = 1570) and identify spatiotemporal clusters of different prey based on predator diet estimates. Quantitative fatty acid signature analysis and the Getis-Ord Gi* statistic identified spatial clusters of high or low dietary proportions (i.e., “hot spots” and “cold spots”) reflecting seasonal and spatial availability of prey. Ringed seal (Pusa hispida) was the primary prey of bears throughout Nunavut followed by bearded seal (Erignathus barbatus), although proportional consumption varied spatially. A consistent ringed seal consumption hot spot was found in Gulf of Boothia indicating the importance of year-round availability of ringed seals. Spatial clusters of bearded seal and Atlantic walrus (Odobenus rosmarus rosmarus) throughout Foxe Basin suggested overlapping seasonal distributions and high regional abundance. Bears had consistently high dietary levels of harbour seal (Phoca vitulina) around Southampton Island and along the western coast of Hudson Bay suggesting a possible year-round concentration of this prey. Hot spots of harp seal (Pagophilus groenlandicus) consumption were evident throughout Davis Strait and a spring-summer hot spot around Jones Sound was consistent with harp seal migratory patterns. Year-round beluga whale (Delphinapterus leucas) hot spots were found along eastern Baffin Island and southern Viscount Melville Sound providing new knowledge of local conditions that promote polar bear predation or scavenging. Narwhal (Monodon monoceros) were less susceptible to predation with only one spatial cluster of high consumption appearing during spring-summer in Barrow Strait. Bowhead whale (Balaena mysticetus) hot spots occurred around south-western Foxe Basin and seasonally in southern Viscount Melville Sound suggesting carcasses are locally accessible to bears and may act as a supplemental food source in particular areas and seasons. The congruence of polar bear feeding habits and known prey distribution suggests polar bears serve as ecological indicators and ongoing monitoring of their diets may reveal regional and broad-scale changes in prey population distributions and Arctic ecosystem functioning. |
| first_indexed | 2024-12-14T23:40:22Z |
| format | Article |
| id | doaj.art-66e810957203458080189e7358a79ba7 |
| institution | Directory Open Access Journal |
| issn | 1470-160X |
| language | English |
| last_indexed | 2024-12-14T23:40:22Z |
| publishDate | 2021-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ecological Indicators |
| spelling | doaj.art-66e810957203458080189e7358a79ba72022-12-21T22:43:31ZengElsevierEcological Indicators1470-160X2021-12-01132108245Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, CanadaMelissa P. Galicia0Gregory W. Thiemann1Markus G. Dyck2Steven H. Ferguson3Department of Biology, York University, Toronto, Ontario, Canada; Corresponding author at: Department of Biology, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada.Department of Biology, York University, Toronto, Ontario, Canada; Faculty of Environmental and Urban Change, York University, Toronto, Ontario, CanadaWildlife Research Section, Department of Environment, Government of Nunavut, Igloolik, Nunavut, CanadaFisheries and Oceans Canada, Arctic Region, Winnipeg, Manitoba, CanadaClimate warming and associated physical and biological changes will likely force widespread species redistribution, particularly in polar environments. However, tracking such distributional shifts is difficult. The dietary habits of apex predators, like polar bears (Ursus maritimus), may provide early signals of distributional change in prey populations. We used harvest-based sampling to investigate the spatial feeding patterns of polar bears across Nunavut from 2010 to 2018 (n = 1570) and identify spatiotemporal clusters of different prey based on predator diet estimates. Quantitative fatty acid signature analysis and the Getis-Ord Gi* statistic identified spatial clusters of high or low dietary proportions (i.e., “hot spots” and “cold spots”) reflecting seasonal and spatial availability of prey. Ringed seal (Pusa hispida) was the primary prey of bears throughout Nunavut followed by bearded seal (Erignathus barbatus), although proportional consumption varied spatially. A consistent ringed seal consumption hot spot was found in Gulf of Boothia indicating the importance of year-round availability of ringed seals. Spatial clusters of bearded seal and Atlantic walrus (Odobenus rosmarus rosmarus) throughout Foxe Basin suggested overlapping seasonal distributions and high regional abundance. Bears had consistently high dietary levels of harbour seal (Phoca vitulina) around Southampton Island and along the western coast of Hudson Bay suggesting a possible year-round concentration of this prey. Hot spots of harp seal (Pagophilus groenlandicus) consumption were evident throughout Davis Strait and a spring-summer hot spot around Jones Sound was consistent with harp seal migratory patterns. Year-round beluga whale (Delphinapterus leucas) hot spots were found along eastern Baffin Island and southern Viscount Melville Sound providing new knowledge of local conditions that promote polar bear predation or scavenging. Narwhal (Monodon monoceros) were less susceptible to predation with only one spatial cluster of high consumption appearing during spring-summer in Barrow Strait. Bowhead whale (Balaena mysticetus) hot spots occurred around south-western Foxe Basin and seasonally in southern Viscount Melville Sound suggesting carcasses are locally accessible to bears and may act as a supplemental food source in particular areas and seasons. The congruence of polar bear feeding habits and known prey distribution suggests polar bears serve as ecological indicators and ongoing monitoring of their diets may reveal regional and broad-scale changes in prey population distributions and Arctic ecosystem functioning.http://www.sciencedirect.com/science/article/pii/S1470160X21009109Polar bearsArcticMarine mammalsDietSpatial distributionQuantitative fatty acid signature analysis (QFASA) |
| spellingShingle | Melissa P. Galicia Gregory W. Thiemann Markus G. Dyck Steven H. Ferguson Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, Canada Ecological Indicators Polar bears Arctic Marine mammals Diet Spatial distribution Quantitative fatty acid signature analysis (QFASA) |
| title | Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, Canada |
| title_full | Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, Canada |
| title_fullStr | Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, Canada |
| title_full_unstemmed | Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, Canada |
| title_short | Polar bear diet composition reveals spatiotemporal distribution of Arctic marine mammals across Nunavut, Canada |
| title_sort | polar bear diet composition reveals spatiotemporal distribution of arctic marine mammals across nunavut canada |
| topic | Polar bears Arctic Marine mammals Diet Spatial distribution Quantitative fatty acid signature analysis (QFASA) |
| url | http://www.sciencedirect.com/science/article/pii/S1470160X21009109 |
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