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Tschritter CM, van Coeverden de Groot P, Branigan M, Dyck M, Sun Z, Jenkins E, Buhler K, Lougheed SC. The geographic distribution, and the biotic and abiotic predictors of select zoonotic pathogen detections in Canadian polar bears. Sci Rep 2024; 14:12027. [PMID: 38797747 PMCID: PMC11128453 DOI: 10.1038/s41598-024-62800-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 05/21/2024] [Indexed: 05/29/2024] Open
Abstract
Increasing Arctic temperatures are facilitating the northward expansion of more southerly hosts, vectors, and pathogens, exposing naïve populations to pathogens not typical at northern latitudes. To understand such rapidly changing host-pathogen dynamics, we need sensitive and robust surveillance tools. Here, we use a novel multiplexed magnetic-capture and droplet digital PCR (ddPCR) tool to assess a sentinel Arctic species, the polar bear (Ursus maritimus; n = 68), for the presence of five zoonotic pathogens (Erysipelothrix rhusiopathiae, Francisella tularensis, Mycobacterium tuberculosis complex, Toxoplasma gondii and Trichinella spp.), and observe associations between pathogen presence and biotic and abiotic predictors. We made two novel detections: the first detection of a Mycobacterium tuberculosis complex member in Arctic wildlife and the first of E. rhusiopathiae in a polar bear. We found a prevalence of 37% for E. rhusiopathiae, 16% for F. tularensis, 29% for Mycobacterium tuberculosis complex, 18% for T. gondii, and 75% for Trichinella spp. We also identify associations with bear age (Trichinella spp.), harvest season (F. tularensis and MTBC), and human settlements (E. rhusiopathiae, F. tularensis, MTBC, and Trichinella spp.). We demonstrate that monitoring a sentinel species, the polar bear, could be a powerful tool in disease surveillance and highlight the need to better characterize pathogen distributions and diversity in the Arctic.
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Affiliation(s)
| | | | - Marsha Branigan
- Department of Environment and Climate Change, Government of the Northwest Territories, Inuvik, Northwest Territories, Canada
| | - Markus Dyck
- Department of Environment, Government of Nunavut, Igloolik, NT, Canada
| | - Zhengxin Sun
- Department of Biology, Queen's University, Kingston, ON, Canada
| | - Emily Jenkins
- Western College of Veterinary Medicine (WCVM), Saskatoon, SK, Canada
| | - Kayla Buhler
- Western College of Veterinary Medicine (WCVM), Saskatoon, SK, Canada
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2
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Newediuk L, Bath DR. Meta-analysis reveals between-population differences affect the link between glucocorticoids and population health. CONSERVATION PHYSIOLOGY 2023; 11:coad005. [PMID: 36845329 PMCID: PMC9945071 DOI: 10.1093/conphys/coad005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Glucocorticoids are a popular tool for monitoring health of animal populations because they can increase with environmental stressors and can indicate chronic stress. However, individual responses to stressors create variation in the glucocorticoid-fitness relationship within populations. The inconsistency in this relationship calls into question the widespread use of glucocorticoids in conservation. We investigated the sources of variation in the glucocorticoid-fitness relationship by conducting a meta-analysis across a diverse set of species exposed to conservation-relevant stressors. We first quantified the extent to which studies inferred population health from glucocorticoids without first validating the glucocorticoid-fitness relationship in their own populations. We also tested whether population-level information like life history stage, sex and species longevity influenced the relationship between glucocorticoids and fitness. Finally, we tested for a universally consistent relationship between glucocorticoids and fitness across studies. We found more than half of peer-reviewed studies published between 2008 and 2022 inferred population health solely based on glucocorticoid levels. While life history stage explained some variation in the relationship between glucocorticoids and fitness, we found no consistent relationship between them. Much of the variation in the relationship could be the result of idiosyncratic characteristics of declining populations, such as unstable demographic structure, that coincided with large amounts of variation in glucocorticoid production. We suggest that conservation biologists capitalize on this variation in glucocorticoid production by declining populations by using the variance in glucocorticoid production as an early warning for declines in population health.
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Affiliation(s)
- Levi Newediuk
- Corresponding author: Department of Biology, Memorial University, 45 Arctic Avenue, St. John's, Newfoundland A1B 3X9, Canada.
| | - Devon R Bath
- Department of Ocean Sciences, Memorial University, 0 Marine Lab Road, St. John's, Newfoundland A1C 5S7, Canada
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3
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Laidre KL, Supple MA, Born EW, Regehr EV, Wiig Ø, Ugarte F, Aars J, Dietz R, Sonne C, Hegelund P, Isaksen C, Akse GB, Cohen B, Stern HL, Moon T, Vollmers C, Corbett-Detig R, Paetkau D, Shapiro B. Glacial ice supports a distinct and undocumented polar bear subpopulation persisting in late 21st-century sea-ice conditions. Science 2022; 376:1333-1338. [PMID: 35709290 DOI: 10.1126/science.abk2793] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Polar bears are susceptible to climate warming because of their dependence on sea ice, which is declining rapidly. We present the first evidence for a genetically distinct and functionally isolated group of polar bears in Southeast Greenland. These bears occupy sea-ice conditions resembling those projected for the High Arctic in the late 21st century, with an annual ice-free period that is >100 days longer than the estimated fasting threshold for the species. Whereas polar bears in most of the Arctic depend on annual sea ice to catch seals, Southeast Greenland bears have a year-round hunting platform in the form of freshwater glacial mélange. This suggests that marine-terminating glaciers, although of limited availability, may serve as previously unrecognized climate refugia. Conservation of Southeast Greenland polar bears, which meet criteria for recognition as the world's 20th polar bear subpopulation, is necessary to preserve the genetic diversity and evolutionary potential of the species.
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Affiliation(s)
- Kristin L Laidre
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA 98105, USA.,Greenland Institute of Natural Resources, 3900 Nuuk, Greenland
| | - Megan A Supple
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Erik W Born
- Greenland Institute of Natural Resources, 3900 Nuuk, Greenland
| | - Eric V Regehr
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA 98105, USA
| | - Øystein Wiig
- Natural History Museum, University of Oslo, Blindern, NO-0318 Oslo, Norway
| | - Fernando Ugarte
- Greenland Institute of Natural Resources, 3900 Nuuk, Greenland
| | - Jon Aars
- Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway
| | - Rune Dietz
- Department of Ecoscience and Arctic Research Centre, Aarhus University, DK-4000 Roskilde, Denmark
| | - Christian Sonne
- Department of Ecoscience and Arctic Research Centre, Aarhus University, DK-4000 Roskilde, Denmark
| | - Peter Hegelund
- Greenland Institute of Natural Resources, 3900 Nuuk, Greenland
| | - Carl Isaksen
- Greenland Institute of Natural Resources, 3900 Nuuk, Greenland
| | | | - Benjamin Cohen
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA 98105, USA
| | - Harry L Stern
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA 98105, USA
| | - Twila Moon
- National Snow and Ice Data Center, Cooperative Institute for Research In Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
| | - Christopher Vollmers
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Russ Corbett-Detig
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - David Paetkau
- Wildlife Genetics International, Nelson, BC V1L 5P9, Canada
| | - Beth Shapiro
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.,Howard Hughes Medical Institute, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
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4
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Vongraven D, Derocher AE, Pilfold NW, Yoccoz NG. Polar Bear Harvest Patterns Across the Circumpolar Arctic. FRONTIERS IN CONSERVATION SCIENCE 2022. [DOI: 10.3389/fcosc.2022.836544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Wildlife harvest remains a conservation concern for many species and assessing patterns of harvest can provide insights on sustainability and inform management. Polar bears (Ursus maritimus) are harvested over a large part of their range by local people. The species has a history of unsustainable harvest that was largely rectified by an international agreement that required science-based management. The objective of our study was to examine the temporal patterns in the number of polar bears harvested, harvest sex ratios, and harvest rates from 1970 to 2018. We analyzed data from 39,049 harvested polar bears (annual mean 797 bears) collected from 1970 to 2018. Harvest varied across populations and times that reflect varying management objectives, episodic events, and changes based on new population estimates. More males than females were harvested with an overall M:F sex ratio of 1.84. Harvest varied by jurisdiction with 68.0% of bears harvested in Canada, 18.0% in Greenland, 11.8% in the USA, and 2.2% in Norway. Harvest rate was often near the 4.5% target rate. Where data allowed harvest rate estimation, the target rate was exceeded in 11 of 13 populations with 1–5 populations per year above the target since 1978. Harvest rates at times were up to 15.9% of the estimated population size suggesting rare episodes of severe over-harvest. Harvest rate was unrelated to a proxy for ecosystem productivity (area of continental shelf within each population) but was correlated with prey diversity. In the last 5–10 years, monitored populations all had harvest rates near sustainable limits, suggesting improvements in management. Polar bear harvest management has reduced the threat it once posed to the species. However, infrequent estimates of abundance, new management objectives, and climate change have raised new concerns about the effects of harvest.
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5
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Performance of helicopter-based biopsy darting of polar bears (Ursus maritimus) on the spring sea ice. EUR J WILDLIFE RES 2021. [DOI: 10.1007/s10344-021-01550-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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An on-ice aerial survey of the Kane Basin polar bear (Ursus maritimus) subpopulation. Polar Biol 2021; 45:89-100. [PMID: 35125636 PMCID: PMC8776663 DOI: 10.1007/s00300-021-02974-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 10/16/2021] [Accepted: 11/15/2021] [Indexed: 10/28/2022]
Abstract
AbstractThere is an imminent need to collect information on distribution and abundance of polar bears (Ursus maritimus) to understand how they are affected by the ongoing decrease in Arctic sea ice. The Kane Basin (KB) subpopulation is a group of high-latitude polar bears that ranges between High Arctic Canada and NW Greenland around and north of the North Water polynya (NOW). We conducted a line transect distance sampling aerial survey of KB polar bears during 28 April–12 May 2014. A total of 4160 linear kilometers were flown in a helicopter over fast ice in the fjords and over offshore pack ice between 76° 50′ and 80° N′. Using a mark-recapture distance sampling protocol, the estimated abundance was 190 bears (95% lognormal CI: 87–411; CV 39%). This estimate is likely negatively biased to an unknown degree because the offshore sectors of the NOW with much open water were not surveyed because of logistical and safety reasons. Our study demonstrated that aerial surveys may be a feasible method for obtaining abundance estimates for small subpopulations of polar bears.
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Galicia MP, Thiemann GW, Dyck MG, Ferguson SH. Are tissue samples obtained via remote biopsy useful for fatty acid-based diet analyses in a free-ranging carnivore? J Mammal 2021. [DOI: 10.1093/jmammal/gyab041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Fundamental knowledge on free-ranging animals has been obtained through capture-based studies; however, these may be logistically intensive, financially expensive, and potentially inconsistent with local cultural values. Genetic mark–recapture using remote tissue sampling has emerged as a less invasive alternative to capture-based population surveys but provides fewer opportunities to collect samples and measurements for broader ecological studies. We compared lipid content, fatty acid (FA) composition, and diet estimates from adipose tissue of polar bears (Ursus maritimus) obtained from two collection methods: remote biopsies (n = 138) sampled from helicopters and hunter-collected tissue (n = 499) from bears harvested in Davis Strait and Gulf of Boothia, Nunavut, 2010 – 2018. Lipid content of adipose tissue was lower in remote biopsies than harvest samples likely because remote biopsies removed only the outermost layer of subcutaneous tissue, rather than the more metabolically dynamic innermost tissue obtained from harvest samples. In contrast, FA composition was similar between the two collection methods with relatively small proportional differences in individual FAs. For diet estimates in Davis Strait, collection method was not a predictor of prey contribution to diet. In Gulf of Boothia, collection method was a predictor for some prey types, but the differences were relatively minor; the rank order of prey types was similar (e.g., ringed seal; Pusa hispida was consistently the primary prey in diets) and prey proportions differed by < 6% between the collection methods. Results from both methods showed that diets varied by geographic area, season, year, age class, and sex. Our study demonstrates that adipose tissue from remote biopsy provides reliable estimates of polar bear diet based on FA analysis and can be used to monitor underlying ecological changes in Arctic marine food webs.
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Affiliation(s)
| | - Gregory W Thiemann
- Faculty of Environmental and Urban Change, York University, Toronto, Ontario, Canada
| | - Markus G Dyck
- Wildlife Research Section, Department of Environment, Government of Nunavut, Igloolik, Nunavut, Canada
| | - Steven H Ferguson
- Fisheries and Oceans Canada, Central and Arctic Region, Winnipeg, Manitoba, Canada
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8
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Jagielski PM, Dey CJ, Gilchrist HG, Richardson ES, Love OP, Semeniuk CAD. Polar bears are inefficient predators of seabird eggs. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210391. [PMID: 33868701 PMCID: PMC8025307 DOI: 10.1098/rsos.210391] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Climate-mediated sea-ice loss is disrupting the foraging ecology of polar bears (Ursus maritimus) across much of their range. As a result, there have been increased reports of polar bears foraging on seabird eggs across parts of their range. Given that polar bears have evolved to hunt seals on ice, they may not be efficient predators of seabird eggs. We investigated polar bears' foraging performance on common eider (Somateria mollissima) eggs on Mitivik Island, Nunavut, Canada to test whether bear decision-making heuristics are consistent with expectations of optimal foraging theory. Using aerial-drones, we recorded multiple foraging bouts over 11 days, and found that as clutches were depleted to completion, bears did not exhibit foraging behaviours matched to resource density. As the season progressed, bears visited fewer nests overall, but marginally increased their visitation to nests that were already empty. Bears did not display different movement modes related to nest density, but became less selective in their choice of clutches to consume. Lastly, bears that capitalized on visual cues of flushing eider hens significantly increased the number of clutches they consumed; however, they did not use this strategy consistently or universally. The foraging behaviours exhibited by polar bears in this study suggest they are inefficient predators of seabird eggs, particularly in the context of matching behaviours to resource density.
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Affiliation(s)
- Patrick M. Jagielski
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON Canada, N9B 3P4
| | - Cody J. Dey
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON Canada, N9B 3P4
| | - H. Grant Gilchrist
- Science and Technology Branch, Environment and Climate Change Canada, Ottawa, ON Canada
| | - Evan S. Richardson
- Science and Technology Branch, Environment and Climate Change Canada, Winnipeg, MB Canada
| | - Oliver P. Love
- Department of Integrative Biology, University of Windsor, Windsor, ON Canada
| | - Christina A. D. Semeniuk
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON Canada, N9B 3P4
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9
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Laidre KL, Atkinson SN, Regehr EV, Stern HL, Born EW, Wiig Ø, Lunn NJ, Dyck M, Heagerty P, Cohen BR. Transient benefits of climate change for a high-Arctic polar bear (Ursus maritimus) subpopulation. GLOBAL CHANGE BIOLOGY 2020; 26:6251-6265. [PMID: 32964662 DOI: 10.1111/gcb.15286] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
Kane Basin (KB) is one of the world's most northerly polar bear (Ursus maritimus) subpopulations, where bears have historically inhabited a mix of thick multiyear and annual sea ice year-round. Currently, KB is transitioning to a seasonally ice-free region because of climate change. This ecological shift has been hypothesized to benefit polar bears in the near-term due to thinner ice with increased biological production, although this has not been demonstrated empirically. We assess sea-ice changes in KB together with changes in polar bear movements, seasonal ranges, body condition, and reproductive metrics obtained from capture-recapture (physical and genetic) and satellite telemetry studies during two study periods (1993-1997 and 2012-2016). The annual cycle of sea-ice habitat in KB shifted from a year-round ice platform (~50% coverage in summer) in the 1990s to nearly complete melt-out in summer (<5% coverage) in the 2010s. The mean duration between sea-ice retreat and advance increased from 109 to 160 days (p = .004). Between the 1990s and 2010s, adult female (AF) seasonal ranges more than doubled in spring and summer and were significantly larger in all months. Body condition scores improved for all ages and both sexes. Mean litter sizes of cubs-of-the-year (C0s) and yearlings (C1s), and the number of C1s per AF, did not change between decades. The date of spring sea-ice retreat in the previous year was positively correlated with C1 litter size, suggesting smaller litters following years with earlier sea-ice breakup. Our study provides evidence for range expansion, improved body condition, and stable reproductive performance in the KB polar bear subpopulation. These changes, together with a likely increasing subpopulation abundance, may reflect the shift from thick, multiyear ice to thinner, seasonal ice with higher biological productivity. The duration of these benefits is unknown because, under unmitigated climate change, continued sea-ice loss is expected to eventually have negative demographic and ecological effects on all polar bears.
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Affiliation(s)
- Kristin L Laidre
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
- Greenland Institute of Natural Resources, Nuuk, Greenland
| | - Stephen N Atkinson
- Wildlife Research Section, Department of Environment, Government of Nunavut, Igloolik, NU, Canada
| | - Eric V Regehr
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Harry L Stern
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Erik W Born
- Greenland Institute of Natural Resources, Nuuk, Greenland
| | - Øystein Wiig
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Nicholas J Lunn
- Environment and Climate Change Canada, University of Alberta, Edmonton, AB, Canada
| | - Markus Dyck
- Wildlife Research Section, Department of Environment, Government of Nunavut, Igloolik, NU, Canada
| | - Patrick Heagerty
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - Benjamin R Cohen
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
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10
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Rode KD, Atwood TC, Thiemann GW, St. Martin M, Wilson RR, Durner GM, Regehr EV, Talbot SL, Sage GK, Pagano AM, Simac KS. Identifying reliable indicators of fitness in polar bears. PLoS One 2020; 15:e0237444. [PMID: 32813753 PMCID: PMC7437918 DOI: 10.1371/journal.pone.0237444] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 07/27/2020] [Indexed: 01/08/2023] Open
Abstract
Animal structural body size and condition are often measured to evaluate individual health, identify responses to environmental change and food availability, and relate food availability to effects on reproduction and survival. A variety of condition metrics have been developed but relationships between these metrics and vital rates are rarely validated. Identifying an optimal approach to estimate the body condition of polar bears is needed to improve monitoring of their response to decline in sea ice habitat. Therefore, we examined relationships between several commonly used condition indices (CI), body mass, and size with female reproductive success and cub survival among polar bears (Ursus maritimus) measured in two subpopulations over three decades. To improve measurement and application of morphometrics and CIs, we also examined whether CIs are independent of age and structural size–an important assumption for monitoring temporal trends—and factors affecting measurement precision and accuracy. Maternal CIs and mass measured the fall prior to denning were related to cub production. Similarly, maternal CIs, mass, and length were related to the mass of cubs or yearlings that accompanied her. However, maternal body mass, but not CIs, measured in the spring was related to cub production and only maternal mass and length were related to the probability of cub survival. These results suggest that CIs may not be better indicators of fitness than body mass in part because CIs remove variation associated with body size that is important in affecting fitness. Further, CIs exhibited variable relationships with age for growing bears and were lower for longer bears despite body length being related to cub survival and female reproductive success. These results are consistent with findings from other species indicating that body mass is a useful metric to link environmental conditions and population dynamics.
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Affiliation(s)
- Karyn D. Rode
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
- * E-mail:
| | - Todd C. Atwood
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
| | | | - Michelle St. Martin
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, Alaska, United States of America
| | - Ryan R. Wilson
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, Alaska, United States of America
| | - George M. Durner
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
| | - Eric V. Regehr
- University of Washington, Polar Science Center, Seattle, Washington, United States of America
| | - Sandra L. Talbot
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
| | - George K. Sage
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
| | - Anthony M. Pagano
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
| | - Kristin S. Simac
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
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11
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Laidre KL, Atkinson S, Regehr EV, Stern HL, Born EW, Wiig Ø, Lunn NJ, Dyck M. Interrelated ecological impacts of climate change on an apex predator. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02071. [PMID: 31925853 PMCID: PMC7317597 DOI: 10.1002/eap.2071] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/12/2019] [Accepted: 11/11/2019] [Indexed: 05/29/2023]
Abstract
Climate change has broad ecological implications for species that rely on sensitive habitats. For some top predators, loss of habitat is expected to lead to cascading behavioral, nutritional, and reproductive changes that ultimately accelerate population declines. In the case of the polar bear (Ursus maritimus), declining Arctic sea ice reduces access to prey and lengthens seasonal fasting periods. We used a novel combination of physical capture, biopsy darting, and visual aerial observation data to project reproductive performance for polar bears by linking sea ice loss to changes in habitat use, body condition (i.e., fatness), and cub production. Satellite telemetry data from 43 (1991-1997) and 38 (2009-2015) adult female polar bears in the Baffin Bay subpopulation showed that bears now spend an additional 30 d on land (90 d in total) in the 2000s compared to the 1990s, a change closely correlated with changes in spring sea ice breakup and fall sea ice formation. Body condition declined for all sex, age, and reproductive classes and was positively correlated with sea ice availability in the current and previous year. Furthermore, cub litter size was positively correlated with maternal condition and spring breakup date (i.e., later breakup leading to larger litters), and negatively correlated with the duration of the ice-free period (i.e., longer ice-free periods leading to smaller litters). Based on these relationships, we projected reproductive performance three polar bear generations into the future (approximately 35 yr). Results indicate that two-cub litters, previously the norm, could largely disappear from Baffin Bay as sea ice loss continues. Our findings demonstrate how concurrent analysis of multiple data types collected over long periods from polar bears can provide a mechanistic understanding of the ecological implications of climate change. This information is needed for long-term conservation planning, which includes quantitative harvest risk assessments that incorporate estimated or assumed trends in future environmental carrying capacity.
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Affiliation(s)
- Kristin L. Laidre
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWashington98105USA
| | - Stephen Atkinson
- Wildlife Research SectionDepartment of EnvironmentGovernment of NunavutP.O. Box 209IgloolikNunavutX0A 0L0Canada
| | - Eric V. Regehr
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWashington98105USA
| | - Harry L. Stern
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWashington98105USA
| | - Erik W. Born
- Greenland Institute of Natural ResourcesP.O. Box 5703900NuukGreenland
| | - Øystein Wiig
- Natural History MuseumUniversity of OsloP.O. Box 1172BlindernN‐0318OsloNorway
| | - Nicholas J. Lunn
- Environment and Climate Change CanadaCW‐422 Biological Sciences BuildingUniversity of AlbertaEdmontonAlbertaT6G 2E9Canada
| | - Markus Dyck
- Wildlife Research SectionDepartment of EnvironmentGovernment of NunavutP.O. Box 209IgloolikNunavutX0A 0L0Canada
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12
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Identifying individual polar bears at safe distances: A test with captive animals. PLoS One 2020; 15:e0228991. [PMID: 32053691 PMCID: PMC7018014 DOI: 10.1371/journal.pone.0228991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 01/28/2020] [Indexed: 11/20/2022] Open
Abstract
The need to recognise individuals in population and behavioural studies has stimulated the development of various identification methods. A commonly used method is to employ natural markers to distinguish individuals. In particular, the automated processing of photographs of study animals has gained interest due to the speed of processing and the ability to handle a high volume of records. However, automated processing requires high-quality photographs, which means that they need to be taken from a specific angle or at close distances. Polar bears Ursus maritimus, for example, may be identified by automated analysis of whisker spot patterns. However, to obtain photographs of adequate quality, the animals need to be closer than is usually possible without risk to animal or observer. In this study we tested the accuracy of an alternative method to identify polar bears at further distances. This method is based on distinguishing a set of physiognomic characteristics, which can be recognised from photographs taken in the field at distances of up to 400 m. During five trials, sets of photographs of 15 polar bears from six zoos, with each individual bear portrayed on different dates, were presented for identification to ten test observers. Among observers the repeatability of the assessments was 0.68 (SE 0.011). Observers with previous training in photogrammetric techniques performed better than observers without training. Experience with observing polar bears in the wild did not improve skills to identify individuals on photographs. Among the observers with photogrammetric experience, the rate of erroneous assessment was on average 0.13 (SE 0.020). For the inexperienced group this was 0.72 (SE 0.018). Error rates obtained with automated whisker spot analysis were intermediate (0.26–0.58). We suggest that wildlife studies will benefit from applying several identification techniques to collect data under different conditions.
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13
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Durner GM, Douglas DC, Atwood TC. Are polar bear habitat resource selection functions developed from 1985-1995 data still useful? Ecol Evol 2019; 9:8625-8638. [PMID: 31410267 PMCID: PMC6686286 DOI: 10.1002/ece3.5401] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 05/20/2019] [Accepted: 05/28/2019] [Indexed: 02/04/2023] Open
Abstract
Greenhouse-gas-induced warming in the Arctic has caused declines in sea ice extent and changed its composition, raising concerns by all circumpolar nations for polar bear conservation.Negative impacts have been observed in three well-studied polar bear subpopulations. Most subpopulations, however, receive little or no direct monitoring, hence, resource selection functions (RSF) may provide a useful proxy of polar bear distributions. However, the efficacy of RSFs constructed from past data, that is, reference RSFs, may be degraded under contemporary conditions, especially in a rapidly changing environment.We assessed published Arctic-wide reference RSFs using tracking data from adult female polar bears captured in the Beaufort Sea. We compared telemetry-derived seasonal distributions of polar bears to RSF-defined optimal sea ice habitat during the period of RSF model development, 1985-1995, and two subsequent periods with diminished sea ice: 1996-2006 and 2007-2016. From these comparisons, we assessed the applicability of the reference RSFs for contemporary polar bear conservation.In the two decades following the 1985-1995 reference period, use and availability of optimal habitat by polar bears declined during the ice melt, ice minimum, and ice growth seasons. During the ice maximum season (i.e., winter), polar bears used the best habitat available, which changed relatively little across the three decades of study. During the ice melt, ice minimum, and ice growth seasons, optimal habitat in areas used by polar bears decreased and was displaced north and east of the Alaska Beaufort Sea coast. As optimal habitat diminished in these seasons, polar bears expanded their range and occupied greater areas of suboptimal habitat.Synthesis and applications: Sea ice declines due to climate change continue to challenge polar bears and their conservation. The distribution of Southern Beaufort Sea polar bears remained similar during the ice maximum season, so the reference RSFs developed from data collected >20 years ago continue to accurately model their winter distribution. In contrast, reference RSFs for the ice transitional and minimum seasons showed diminished predictive efficacy but were useful in revealing that contemporary polar bears have been increasingly forced to use suboptimal habitats during those seasons.
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Affiliation(s)
| | | | - Todd C. Atwood
- Alaska Science CenterU.S. Geological SurveyAnchorageAlaskaUSA
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14
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Routti H, Atwood TC, Bechshoft T, Boltunov A, Ciesielski TM, Desforges JP, Dietz R, Gabrielsen GW, Jenssen BM, Letcher RJ, McKinney MA, Morris AD, Rigét FF, Sonne C, Styrishave B, Tartu S. State of knowledge on current exposure, fate and potential health effects of contaminants in polar bears from the circumpolar Arctic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 664:1063-1083. [PMID: 30901781 DOI: 10.1016/j.scitotenv.2019.02.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/01/2019] [Accepted: 02/02/2019] [Indexed: 05/03/2023]
Abstract
The polar bear (Ursus maritimus) is among the Arctic species exposed to the highest concentrations of long-range transported bioaccumulative contaminants, such as halogenated organic compounds and mercury. Contaminant exposure is considered to be one of the largest threats to polar bears after the loss of their Arctic sea ice habitat due to climate change. The aim of this review is to provide a comprehensive summary of current exposure, fate, and potential health effects of contaminants in polar bears from the circumpolar Arctic required by the Circumpolar Action Plan for polar bear conservation. Overall results suggest that legacy persistent organic pollutants (POPs) including polychlorinated biphenyls, chlordanes and perfluorooctane sulfonic acid (PFOS), followed by other perfluoroalkyl compounds (e.g. carboxylic acids, PFCAs) and brominated flame retardants, are still the main compounds in polar bears. Concentrations of several legacy POPs that have been banned for decades in most parts of the world have generally declined in polar bears. Current spatial trends of contaminants vary widely between compounds and recent studies suggest increased concentrations of both POPs and PFCAs in certain subpopulations. Correlative field studies, supported by in vitro studies, suggest that contaminant exposure disrupts circulating levels of thyroid hormones and lipid metabolism, and alters neurochemistry in polar bears. Additionally, field and in vitro studies and risk assessments indicate the potential for adverse impacts to polar bear immune functions from exposure to certain contaminants.
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Affiliation(s)
- Heli Routti
- Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway.
| | - Todd C Atwood
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA
| | - Thea Bechshoft
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Andrei Boltunov
- Marine Mammal Research and Expedition Center, 36 Nahimovskiy pr., Moscow 117997, Russia
| | - Tomasz M Ciesielski
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Jean-Pierre Desforges
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Rune Dietz
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | | | - Bjørn M Jenssen
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark; Department of Arctic Technology, University Centre in Svalbard, PO Box 156, NO-9171 Longyearbyen, Norway
| | - Robert J Letcher
- Ecotoxicology and Wildlife Heath Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Dr., Ottawa, Ontario K1A 0H3, Canada
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Ste.-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Adam D Morris
- Ecotoxicology and Wildlife Heath Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Dr., Ottawa, Ontario K1A 0H3, Canada
| | - Frank F Rigét
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Christian Sonne
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Bjarne Styrishave
- Toxicology and Drug Metabolism Group, Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen OE, Denmark
| | - Sabrina Tartu
- Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway
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15
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Hamilton SG, Derocher AE. Assessment of global polar bear abundance and vulnerability. Anim Conserv 2018. [DOI: 10.1111/acv.12439] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- S. G. Hamilton
- Department of Biological Sciences University of Alberta Edmonton AB Canada
| | - A. E. Derocher
- Department of Biological Sciences University of Alberta Edmonton AB Canada
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16
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Wilder JM, Vongraven D, Atwood T, Hansen B, Jessen A, Kochnev A, York G, Vallender R, Hedman D, Gibbons M. Polar bear attacks on humans: Implications of a changing climate. WILDLIFE SOC B 2017. [DOI: 10.1002/wsb.783] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- James M. Wilder
- U.S. Fish and Wildlife Service, Marine Mammals Management; 1011 E. Tudor Road Anchorage AK 99503 USA
| | - Dag Vongraven
- Norwegian Polar Institute, Fram Center; N-9296 Tromsø Norway
| | - Todd Atwood
- U.S. Geological Survey, Alaska Science Center; 4210 University Road Anchorage AK 99508 USA
| | - Bob Hansen
- Government of Nunavut; Igloolik NU X0A 0L0 Canada
| | - Amalie Jessen
- Government of Greenland, Department of Wildlife and Agriculture; P.O. Box 269 3900 Nuuk Greenland
| | - Anatoly Kochnev
- Russian Academy of Sciences, Far East Branch, Institute of Biological Problems of the North, Mammals Ecology Lab; 18 Portovaya Street 685000 Magadan Russia
| | - Geoff York
- Polar Bears International; PO Box 3008 Bozeman MT 59772 USA
| | - Rachel Vallender
- Canadian Wildlife Service, Environment Canada; 351 St. Joseph Boulevard Gatineau QC K1A 0H3 Canada
| | - Daryll Hedman
- Manitoba Conservation and Water Stewardship; Northeast Region, Box 28 Thompson MB R8N 1N2 Canada
| | - Melissa Gibbons
- Wapusk National Park and Manitoba North National Historic Sites, Parks Canada; Box 127 Churchill MB R0B 0E0 Canada
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17
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Pagano AM, Rode KD, Cutting A, Owen MA, Jensen S, Ware JV, Robbins CT, Durner GM, Atwood TC, Obbard ME, Middel KR, Thiemann GW, Williams TM. Using tri-axial accelerometers to identify wild polar bear behaviors. ENDANGER SPECIES RES 2017. [DOI: 10.3354/esr00779] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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18
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Atwood TC, Marcot BG, Douglas DC, Amstrup SC, Rode KD, Durner GM, Bromaghin JF. Forecasting the relative influence of environmental and anthropogenic stressors on polar bears. Ecosphere 2016. [DOI: 10.1002/ecs2.1370] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Todd C. Atwood
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
| | - Bruce G. Marcot
- Pacific Northwest Research StationU.S.D.A. Forest Service Portland Oregon 97208 USA
| | - David C. Douglas
- Alaska Science CenterU.S. Geological Survey Juneau Alaska 99801 USA
| | | | - Karyn D. Rode
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
| | - George M. Durner
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
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19
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Tartu S, Bourgeon S, Aars J, Andersen M, Ehrich D, Thiemann GW, Welker JM, Routti H. Geographical Area and Life History Traits Influence Diet in an Arctic Marine Predator. PLoS One 2016; 11:e0155980. [PMID: 27196700 PMCID: PMC4873193 DOI: 10.1371/journal.pone.0155980] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/06/2016] [Indexed: 11/22/2022] Open
Abstract
Global changes are thought to affect most Arctic species, yet some populations are more at risk. Today, the Barents Sea ecoregion is suffering the strongest sea ice retreat ever measured; and these changes are suspected to modify food access and thus diet of several species. Biochemical diet tracers enable investigation of diet in species such as polar bears (Ursus maritimus). We examined individual diet variation of female polar bears in Svalbard, Norway, and related it to year, season (spring and autumn), sampling area and breeding status (solitary, with cubs of the year or yearlings). Sampling areas were split according to their ice cover: North-West (less sea ice cover), South-East (larger amplitude in sea ice extent) and North-East/South-West (NESW) as bears from that zone are more mobile among all regions of Svalbard. We measured fatty acid (FA) composition in adipose tissue and carbon (δ13C) and nitrogen (δ15N) stable isotopes in plasma and red blood cells. Females feeding in the North-West area had lower δ15N values than those from the NESW. In South-East females, δ13C values were lower in autumn compared to spring and females seemed less selective in their diet as depicted by large variances in stable isotope values. Considering the differences in FA composition and stable isotope values, we suggest that females from the North-West and South-East could ingest a higher proportion of avian prey. With regard to breeding status, solitary females had higher δ15N values and smaller variance in their stable isotopic values than females with cubs, suggesting that solitary females were more selective and prey on higher trophic level species (i.e. seals). Overall, our results indicate that prey availability for Svalbard polar bears varies according to geographical area and prey selectivity differs according to breeding status. Our findings suggest that complex changes in sea ice and prey availability will interact to affect Svalbard polar bear feeding patterns and associated nutrition.
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Affiliation(s)
- Sabrina Tartu
- Norwegian Polar Institute, Fram Centre, Tromsø, Norway
- * E-mail:
| | - Sophie Bourgeon
- Norwegian Polar Institute, Fram Centre, Tromsø, Norway
- UiT-The Arctic University of Norway, Department of Arctic and Marine Biology, Tromsø, Norway
| | - Jon Aars
- Norwegian Polar Institute, Fram Centre, Tromsø, Norway
| | | | - Dorothee Ehrich
- UiT-The Arctic University of Norway, Department of Arctic and Marine Biology, Tromsø, Norway
| | | | - Jeffrey M. Welker
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, Alaska, United States of America
- University Center in Svalbard, Longyearbyen, Svalbard, Norway
| | - Heli Routti
- Norwegian Polar Institute, Fram Centre, Tromsø, Norway
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20
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Kutschera VE, Frosch C, Janke A, Skírnisson K, Bidon T, Lecomte N, Fain SR, Eiken HG, Hagen SB, Arnason U, Laidre KL, Nowak C, Hailer F. High genetic variability of vagrant polar bears illustrates importance of population connectivity in fragmented sea ice habitats. Anim Conserv 2016. [DOI: 10.1111/acv.12250] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- V. E. Kutschera
- Senckenberg Biodiversity and Climate Research Centre (BiK-F); Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main; Germany
- Department of Evolutionary Biology, Evolutionary Biology Centre; Uppsala University; Uppsala Sweden
| | - C. Frosch
- Conservation Genetics Group; Senckenberg Research Institute and Natural History Museum Frankfurt; Gelnhausen Germany
| | - A. Janke
- Senckenberg Biodiversity and Climate Research Centre (BiK-F); Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main; Germany
- Institute for Ecology, Evolution and Diversity; Goethe University Frankfurt, Frankfurt am Main; Germany
| | - K. Skírnisson
- Institute for Experimental Pathology; Keldur, University of Iceland; Reykjavík Iceland
| | - T. Bidon
- Senckenberg Biodiversity and Climate Research Centre (BiK-F); Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main; Germany
| | - N. Lecomte
- Canada Research Chair in Polar and Boreal Ecology, Department of Biology; University of Moncton; Moncton NB Canada
- Government of Nunavut; Igloolik NU Canada
| | - S. R. Fain
- National Fish and Wildlife Forensic Laboratory; Ashland OR USA
| | - H. G. Eiken
- NIBIO, Norwegian Institute for Bioeconomy Research; Svanvik Norway
| | - S. B. Hagen
- NIBIO, Norwegian Institute for Bioeconomy Research; Svanvik Norway
| | - U. Arnason
- Faculty of Medicine; University of Lund; Lund Sweden
| | - K. L. Laidre
- Applied Physics Laboratory; Polar Science Center, University of Washington; Seattle WA USA
| | - C. Nowak
- Conservation Genetics Group; Senckenberg Research Institute and Natural History Museum Frankfurt; Gelnhausen Germany
| | - F. Hailer
- Senckenberg Biodiversity and Climate Research Centre (BiK-F); Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main; Germany
- School of Biosciences; Cardiff University; Cardiff, Wales UK
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21
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LaRue MA, Stapleton S, Porter C, Atkinson S, Atwood T, Dyck M, Lecomte N. Testing methods for using high-resolution satellite imagery to monitor polar bear abundance and distribution. WILDLIFE SOC B 2015. [DOI: 10.1002/wsb.596] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Michelle A. LaRue
- Department of Earth Sciences; University of Minnesota; Minneapolis MN 55455 USA
| | - Seth Stapleton
- Department of Fisheries, Wildlife and Conservation Biology; University of Minnesota; St. Paul MN 55108 USA
| | - Claire Porter
- Polar Geospatial Center; University of Minnesota; St. Paul MN 55108 USA
| | - Stephen Atkinson
- Department of Environment; Government of Nunavut; Igloolik Nunavut X0A 0L0 Canada
| | - Todd Atwood
- United States Geological Survey; Alaska Science Center; Anchorage AK 99508 USA
| | - Markus Dyck
- Department of Environment; Government of Nunavut; Igloolik Nunavut X0A 0L0 Canada
| | - Nicolas Lecomte
- Department of Environment; Government of Nunavut; Igloolik Nunavut X0A 0L0 Canada
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22
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Fagre AC, Patyk KA, Nol P, Atwood T, Hueffer K, Duncan C. A Review of Infectious Agents in Polar Bears (Ursus maritimus) and Their Long-Term Ecological Relevance. ECOHEALTH 2015; 12:528-39. [PMID: 25791679 DOI: 10.1007/s10393-015-1023-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 11/13/2014] [Accepted: 02/06/2015] [Indexed: 05/27/2023]
Abstract
Disease was a listing criterion for the polar bear (Ursus maritimus) as threatened under the Endangered Species Act in 2008; it is therefore important to evaluate the current state of knowledge and identify any information gaps pertaining to diseases in polar bears. We conducted a systematic literature review focused on infectious agents and associated health impacts identified in polar bears. Overall, the majority of reports in free-ranging bears concerned serosurveys or fecal examinations with little to no information on associated health effects. In contrast, most reports documenting illness or pathology referenced captive animals and diseases caused by etiologic agents not representative of exposure opportunities in wild bears. As such, most of the available infectious disease literature has limited utility as a basis for development of future health assessment and management plans. Given that ecological change is a considerable risk facing polar bear populations, future work should focus on cumulative effects of multiple stressors that could impact polar bear population dynamics.
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Affiliation(s)
- Anna C Fagre
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, CO, 80524, USA
| | - Kelly A Patyk
- Center for Epidemiology and Animal Health, Science Technology and Analysis Services (STAS), Veterinary Services (VS), Animal and Plant Health Inspection Service (APHIS), United States Department of Agriculture (USDA), 2150 Centre Ave., Fort Collins, CO, 80526, USA
| | - Pauline Nol
- Wildlife-Livestock Disease Investigations Team, STAS, VS, APHIS, USDA, 4101 LaPorte Avenue, Fort Collins, CO, 80521, USA
| | - Todd Atwood
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA
| | - Karsten Hueffer
- Department of Veterinary Medicine, College of Natural Science and Mathematics, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Colleen Duncan
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, CO, 80524, USA.
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23
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Sahanatien V, Peacock E, Derocher AE. Population substructure and space use of Foxe Basin polar bears. Ecol Evol 2015; 5:2851-64. [PMID: 26306171 PMCID: PMC4541990 DOI: 10.1002/ece3.1571] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 05/11/2015] [Accepted: 05/18/2015] [Indexed: 11/19/2022] Open
Abstract
Climate change has been identified as a major driver of habitat change, particularly for sea ice-dependent species such as the polar bear (Ursus maritimus). Population structure and space use of polar bears have been challenging to quantify because of their circumpolar distribution and tendency to range over large areas. Knowledge of movement patterns, home range, and habitat is needed for conservation and management. This is the first study to examine the spatial ecology of polar bears in the Foxe Basin management unit of Nunavut, Canada. Foxe Basin is in the mid-Arctic, part of the seasonal sea ice ecoregion and it is being negatively affected by climate change. Our objectives were to examine intrapopulation spatial structure, to determine movement patterns, and to consider how polar bear movements may respond to changing sea ice habitat conditions. Hierarchical and fuzzy cluster analyses were used to assess intrapopulation spatial structure of geographic position system satellite-collared female polar bears. Seasonal and annual movement metrics (home range, movement rates, time on ice) and home-range fidelity (static and dynamic overlap) were compared to examine the influence of regional sea ice on movements. The polar bears were distributed in three spatial clusters, and there were differences in the movement metrics between clusters that may reflect sea ice habitat conditions. Within the clusters, bears moved independently of each other. Annual and seasonal home-range fidelity was observed, and the bears used two movement patterns: on-ice range residency and annual migration. We predict that home-range fidelity may decline as the spatial and temporal predictability of sea ice changes. These new findings also provide baseline information for managing and monitoring this polar bear population.
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Affiliation(s)
- Vicki Sahanatien
- Department of Biological Sciences, University of AlbertaEdmonton, Alberta, T6G 2E9, Canada
| | - Elizabeth Peacock
- Department of Environment, Government of NunavutIgloolik, Nunavut, X0A 0L0, Canada
| | - Andrew E Derocher
- Department of Biological Sciences, University of AlbertaEdmonton, Alberta, T6G 2E9, Canada
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24
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Laidre KL, Stern H, Kovacs KM, Lowry L, Moore SE, Regehr EV, Ferguson SH, Wiig Ø, Boveng P, Angliss RP, Born EW, Litovka D, Quakenbush L, Lydersen C, Vongraven D, Ugarte F. Arctic marine mammal population status, sea ice habitat loss, and conservation recommendations for the 21st century. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2015; 29:724-37. [PMID: 25783745 PMCID: PMC5008214 DOI: 10.1111/cobi.12474] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 11/18/2014] [Accepted: 12/06/2014] [Indexed: 05/05/2023]
Abstract
Arctic marine mammals (AMMs) are icons of climate change, largely because of their close association with sea ice. However, neither a circumpolar assessment of AMM status nor a standardized metric of sea ice habitat change is available. We summarized available data on abundance and trend for each AMM species and recognized subpopulation. We also examined species diversity, the extent of human use, and temporal trends in sea ice habitat for 12 regions of the Arctic by calculating the dates of spring sea ice retreat and fall sea ice advance from satellite data (1979-2013). Estimates of AMM abundance varied greatly in quality, and few studies were long enough for trend analysis. Of the AMM subpopulations, 78% (61 of 78) are legally harvested for subsistence purposes. Changes in sea ice phenology have been profound. In all regions except the Bering Sea, the duration of the summer (i.e., reduced ice) period increased by 5-10 weeks and by >20 weeks in the Barents Sea between 1979 and 2013. In light of generally poor data, the importance of human use, and forecasted environmental changes in the 21st century, we recommend the following for effective AMM conservation: maintain and improve comanagement by local, federal, and international partners; recognize spatial and temporal variability in AMM subpopulation response to climate change; implement monitoring programs with clear goals; mitigate cumulative impacts of increased human activity; and recognize the limits of current protected species legislation.
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Affiliation(s)
- Kristin L Laidre
- Polar Science Center, Applied Physics Laboratory, 1013 NE 40th Street, University of Washington, Seattle, WA, 98105, U.S.A
- Greenland Institute of Natural Resources, P.O. Box 570, 3900, Nuuk, Greenland
| | - Harry Stern
- Polar Science Center, Applied Physics Laboratory, 1013 NE 40th Street, University of Washington, Seattle, WA, 98105, U.S.A
| | - Kit M Kovacs
- Norwegian Polar Institute, Fram Centre, N-9296, Tromsø, Norway
| | - Lloyd Lowry
- School of Fisheries and Ocean Sciences, University of Alaska, 73-4388, Paiaha Street, Kailua Kona, HI 96740, U.S.A
| | - Sue E Moore
- National Marine Fisheries Service, National Oceanographic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA, 98115, U.S.A
| | - Eric V Regehr
- U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, AK, 99503, U.S.A
| | - Steven H Ferguson
- Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, MB, R3T 2N6, Canada
| | - Øystein Wiig
- Natural History Museum, University of Oslo, P.O. Box 1172, Blindern, N-0318, Oslo, Norway
| | - Peter Boveng
- National Marine Mammal Laboratory, Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, 7600, Sand Point Way NE, Seattle, WA 98115, U.S.A
| | - Robyn P Angliss
- National Marine Mammal Laboratory, Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, 7600, Sand Point Way NE, Seattle, WA 98115, U.S.A
| | - Erik W Born
- Greenland Institute of Natural Resources, P.O. Box 570, 3900, Nuuk, Greenland
| | - Dennis Litovka
- ChukotTINRO, P.O. Box 29, Str. Otke, 56, Anadyr, Chukotka, 689000, Russia
| | - Lori Quakenbush
- Alaska Department of Fish and Game, 1300 College Road, Fairbanks, AK, 99701, U.S.A
| | | | - Dag Vongraven
- Norwegian Polar Institute, Fram Centre, N-9296, Tromsø, Norway
| | - Fernando Ugarte
- Greenland Institute of Natural Resources, P.O. Box 570, 3900, Nuuk, Greenland
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25
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Patyk KA, Duncan C, Nol P, Sonne C, Laidre K, Obbard M, Wiig Ø, Aars J, Regehr E, Gustafson LL, Atwood T. Establishing a definition of polar bear (Ursus maritimus) health: a guide to research and management activities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 514:371-378. [PMID: 25679818 DOI: 10.1016/j.scitotenv.2015.02.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/02/2015] [Accepted: 02/03/2015] [Indexed: 06/04/2023]
Abstract
The meaning of health for wildlife and perspectives on how to assess and measure health, are not well characterized. For wildlife at risk, such as some polar bear (Ursus maritimus) subpopulations, establishing comprehensive monitoring programs that include health status is an emerging need. Environmental changes, especially loss of sea ice habitat, have raised concern about polar bear health. Effective and consistent monitoring of polar bear health requires an unambiguous definition of health. We used the Delphi method of soliciting and interpreting expert knowledge to propose a working definition of polar bear health and to identify current concerns regarding health, challenges in measuring health, and important metrics for monitoring health. The expert opinion elicited through the exercise agreed that polar bear health is defined by characteristics and knowledge at the individual, population, and ecosystem level. The most important threats identified were in decreasing order: climate change, increased nutritional stress, chronic physiological stress, harvest management, increased exposure to contaminants, increased frequency of human interaction, diseases and parasites, and increased exposure to competitors. Fifteen metrics were identified to monitor polar bear health. Of these, indicators of body condition, disease and parasite exposure, contaminant exposure, and reproductive success were ranked as most important. We suggest that a cumulative effects approach to research and monitoring will improve the ability to assess the biological, ecological, and social determinants of polar bear health and provide measurable objectives for conservation goals and priorities and to evaluate progress.
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Affiliation(s)
- Kelly A Patyk
- Center for Epidemiology and Animal Health, Science Technology and Analysis Services, Veterinary Services, Animal and Plant Health Inspection Service, U.S. Department of Agriculture, USA.
| | - Colleen Duncan
- Colorado State University Veterinary Diagnostic Laboratory, Colorado State University, USA
| | - Pauline Nol
- National Wildlife Research Center, Veterinary Services, Animal and Plant Health Inspection Service, U.S. Department of Agriculture, USA
| | - Christian Sonne
- Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Denmark
| | - Kristin Laidre
- Polar Science Center, Applied Physics Laboratory, University of Washington, USA
| | - Martyn Obbard
- Wildlife Research and Monitoring Section, Ontario Ministry of Natural Resources and Forestry, Canada
| | - Øystein Wiig
- Natural History Museum, University of Oslo, Norway
| | - Jon Aars
- Norwegian Polar Institute, Norway
| | - Eric Regehr
- U.S. Fish and Wildlife Service, Marine Mammals Management Program, USA
| | - Lori L Gustafson
- Center for Epidemiology and Animal Health, Science Technology and Analysis Services, Veterinary Services, Animal and Plant Health Inspection Service, U.S. Department of Agriculture, USA
| | - Todd Atwood
- U.S. Geological Survey, Alaska Science Center, USA.
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Rogers MC, Peacock E, Simac K, O’Dell MB, Welker JM. Diet of female polar bears in the southern Beaufort Sea of Alaska: evidence for an emerging alternative foraging strategy in response to environmental change. Polar Biol 2015. [DOI: 10.1007/s00300-015-1665-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wilson RR, Horne JS, Rode KD, Regehr EV, Durner GM. Identifying polar bear resource selection patterns to inform offshore development in a dynamic and changing Arctic. Ecosphere 2014. [DOI: 10.1890/es14-00193.1] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Stapleton S, LaRue M, Lecomte N, Atkinson S, Garshelis D, Porter C, Atwood T. Polar bears from space: assessing satellite imagery as a tool to track Arctic wildlife. PLoS One 2014; 9:e101513. [PMID: 25006979 PMCID: PMC4090068 DOI: 10.1371/journal.pone.0101513] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 06/09/2014] [Indexed: 11/18/2022] Open
Abstract
Development of efficient techniques for monitoring wildlife is a priority in the Arctic, where the impacts of climate change are acute and remoteness and logistical constraints hinder access. We evaluated high resolution satellite imagery as a tool to track the distribution and abundance of polar bears. We examined satellite images of a small island in Foxe Basin, Canada, occupied by a high density of bears during the summer ice-free season. Bears were distinguished from other light-colored spots by comparing images collected on different dates. A sample of ground-truthed points demonstrated that we accurately classified bears. Independent observers reviewed images and a population estimate was obtained using mark-recapture models. This estimate (N: 94; 95% Confidence Interval: 92-105) was remarkably similar to an abundance estimate derived from a line transect aerial survey conducted a few days earlier (N: 102; 95% CI: 69-152). Our findings suggest that satellite imagery is a promising tool for monitoring polar bears on land, with implications for use with other Arctic wildlife. Large scale applications may require development of automated detection processes to expedite review and analysis. Future research should assess the utility of multi-spectral imagery and examine sites with different environmental characteristics.
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Affiliation(s)
- Seth Stapleton
- United States Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
| | - Michelle LaRue
- Department of Earth Sciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Nicolas Lecomte
- Department of Environment, Government of Nunavut, Igloolik, Nunavut, Canada
| | - Stephen Atkinson
- Department of Environment, Government of Nunavut, Igloolik, Nunavut, Canada
| | - David Garshelis
- Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, St. Paul, Minnesota, United States of America
- Minnesota Department of Natural Resources, Grand Rapids, Minnesota, United States of America
| | - Claire Porter
- Department of Earth Sciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Todd Atwood
- United States Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
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McKinney MA, Atwood T, Dietz R, Sonne C, Iverson SJ, Peacock E. Validation of adipose lipid content as a body condition index for polar bears. Ecol Evol 2014; 4:516-27. [PMID: 24634735 PMCID: PMC3936397 DOI: 10.1002/ece3.956] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 11/09/2022] Open
Abstract
Body condition is a key indicator of individual and population health. Yet, there is little consensus as to the most appropriate condition index (CI), and most of the currently used CIs have not been thoroughly validated and are logistically challenging. Adipose samples from large datasets of capture biopsied, remote biopsied, and harvested polar bears were used to validate adipose lipid content as a CI via tests of accuracy, precision, sensitivity, biopsy depth, and storage conditions and comparisons to established CIs, to measures of health and to demographic and ecological parameters. The lipid content analyses of even very small biopsy samples were highly accurate and precise, but results were influenced by tissue depth at which the sample was taken. Lipid content of capture biopsies and samples from harvested adult females was correlated with established CIs and/or conformed to expected biological variation and ecological changes. However, lipid content of remote biopsies was lower than capture biopsies and harvested samples, possibly due to lipid loss during dart retrieval. Lipid content CI is a biologically relevant, relatively inexpensive and rapidly assessed CI and can be determined routinely for individuals and populations in order to infer large-scale spatial and long-term temporal trends. As it is possible to collect samples during routine harvesting or remotely using biopsy darts, monitoring and assessment of body condition can be accomplished without capture and handling procedures or noninvasively, which are methods that are preferred by local communities. However, further work is needed to apply the method to remote biopsies.
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Affiliation(s)
- Melissa A McKinney
- Department of Biology, Dalhousie University Halifax, Nova Scotia, B3H 4R2, Canada ; Great Lakes Institute for Environmental Research, University of Windsor Windsor, Ontario, N9B 3P4, Canada
| | - Todd Atwood
- US Geological Survey, Alaska Science Center Anchorage, Alaska, 99508
| | - Rune Dietz
- Department of Biological Sciences, Arctic Research Centre, Aarhus University Roskilde, DK-4000, Denmark
| | - Christian Sonne
- Department of Biological Sciences, Arctic Research Centre, Aarhus University Roskilde, DK-4000, Denmark
| | - Sara J Iverson
- Department of Biology, Dalhousie University Halifax, Nova Scotia, B3H 4R2, Canada
| | - Elizabeth Peacock
- US Geological Survey, Alaska Science Center Anchorage, Alaska, 99508
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Herreman J, Peacock E. Polar bear use of a persistent food subsidy: Insights from non-invasive genetic sampling in Alaska. URSUS 2013. [DOI: 10.2192/ursus-d-12-00030.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Bechshøft TØ, Sonne C, Rigét FF, Letcher RJ, Novak MA, Henchey E, Meyer JS, Eulaers I, Jaspers VLB, Covaci A, Dietz R. Polar bear stress hormone cortisol fluctuates with the North Atlantic Oscillation climate index. Polar Biol 2013. [DOI: 10.1007/s00300-013-1364-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Thiemann GW, Derocher AE, Cherry SG, Lunn NJ, Peacock E, Sahanatien V. Effects of chemical immobilization on the movement rates of free-ranging polar bears. J Mammal 2013. [DOI: 10.1644/12-mamm-a-230.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Derocher AE, Aars J, Amstrup SC, Cutting A, Lunn NJ, Molnár PK, Obbard ME, Stirling I, Thiemann GW, Vongraven D, Wiig Ø, York G. Rapid ecosystem change and polar bear conservation. Conserv Lett 2013. [DOI: 10.1111/conl.12009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Andrew E. Derocher
- Department of Biological Sciences, University of Alberta; Edmonton; AB T6G 2E9; Canada
| | - Jon Aars
- Norwegian Polar Institute, Fram Centre; 9296; Tromsø; Norway
| | | | | | - Nick J. Lunn
- Wildlife Research Division, Science and Technology Branch, Environment Canada,; 5320 122 Street; Edmonton; AB T6H 3S5; Canada
| | - Péter K. Molnár
- Ecology and Evolutionary Biology, Eno Hall, Princeton University; Princeton; NJ; 08544-1003; USA
| | - Martyn E. Obbard
- Wildlife Research and Development Section, Ontario Ministry of Natural Resources, DNA Building, Trent University; 2140 East Bank Drive; Peterborough; ON K9J 7B8; Canada
| | | | - Gregory W. Thiemann
- Faculty of Environmental Studies, York University; Toronto; ON; M3J 1P3; Canada
| | - Dag Vongraven
- Norwegian Polar Institute, Fram Centre; 9296; Tromsø; Norway
| | - Øystein Wiig
- National Centre for Biosystematics, Natural History Museum, University of Oslo; PO Box 1172; Blindern 0318 Oslo; Norway
| | - Geoffrey York
- Arctic Species Conservation, WWF Global Arctic Programme; 30 Metcalfe Street; Suite 400; Ottawa; ON K1P 5L4; Canada
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