1
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Rode KD, Taras BD, Stricker CA, Atwood TC, Boucher NP, Durner GM, Derocher AE, Richardson ES, Cherry SG, Quakenbush L, Horstmann L, Bromaghin JF. Diet energy density estimated from isotopes in predator hair associated with survival, habitat, and population dynamics. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2751. [PMID: 36151883 DOI: 10.1002/eap.2751] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/29/2022] [Accepted: 08/30/2022] [Indexed: 06/16/2023]
Abstract
Sea ice loss is fundamentally altering the Arctic marine environment. Yet there is a paucity of data on the adaptability of food webs to ecosystem change, including predator-prey interactions. Polar bears (Ursus maritimus) are an important subsistence resource for Indigenous people and an apex predator that relies entirely on the under-ice food web to meet its energy needs. In this study, we assessed whether polar bears maintained dietary energy density by prey switching in response to spatiotemporal variation in prey availability. We compared the macronutrient composition of diets inferred from stable carbon and nitrogen isotopes in polar bear guard hair (primarily representing summer/fall diet) during periods when bears had low and high survival (2004-2016), between bears that summered on land versus pack ice, and between bears occupying different regions of the Alaskan and Canadian Beaufort Sea. Polar bears consumed diets with lower energy density during periods of low survival, suggesting that concurrent increased dietary proportions of beluga whales (Delphinapterus leucas) did not offset reduced proportions of ringed seals (Pusa hispida). Diets with the lowest energy density and proportions from ringed seal blubber were consumed by bears in the western Beaufort Sea (Alaska) during a period when polar bear abundance declined. Intake required to meet energy requirements of an average free-ranging adult female polar bear was 2.1 kg/day on diets consumed during years with high survival but rose to 3.0 kg/day when survival was low. Although bears that summered onshore in the Alaskan Beaufort Sea had higher-fat diets than bears that summered on the pack ice, access to the remains of subsistence-harvested bowhead whales (Balaena mysticetus) contributed little to improving diet energy density. Because most bears in this region remain with the sea ice year round, prey switching and consumption of whale carcasses onshore appear insufficient to augment diets when availability of their primary prey, ringed seals, is reduced. Our results show that a strong predator-prey relationship between polar bears and ringed seals continues in the Beaufort Sea. The method of estimating dietary blubber using predator hair, demonstrated here, provides a new metric to monitor predator-prey relationships that affect individual health and population demographics.
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Affiliation(s)
- Karyn D Rode
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA
| | - Brian D Taras
- Alaska Department of Fish and Game, Fairbanks, Alaska, USA
| | - Craig A Stricker
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, USA
| | - Todd C Atwood
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA
| | - Nicole P Boucher
- University of Alberta, Edmonton, Alberta, Canada
- School of Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - George M Durner
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA
| | | | - Evan S Richardson
- Environment and Climate Change Canada, Science and Technology Branch, Winnipeg, Manitoba, Canada
| | - Seth G Cherry
- University of Alberta, Edmonton, Alberta, Canada
- Parks Canada, East Kootenay, British Columbia, Canada
| | | | - Lara Horstmann
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA
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2
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Rode KD, Douglas D, Atwood T, Durner G, Wilson R, Pagano A. Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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3
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Whiteman JP, Harlow HJ, Durner GM, Regehr EV, Amstrup SC, Pagano AM, Ben‐David M. The acute physiological response of polar bears to helicopter capture. J Wildl Manage 2022; 86:e22238. [PMID: 35915725 PMCID: PMC9324155 DOI: 10.1002/jwmg.22238] [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: 09/04/2021] [Revised: 02/25/2022] [Accepted: 03/29/2022] [Indexed: 11/28/2022]
Abstract
Many wildlife species are live captured, sampled, and released; for polar bears (Ursus maritimus) capture often requires chemical immobilization via helicopter darting. Polar bears reduce their activity for approximately 4 days after capture, likely reflecting stress recovery. To better understand this stress, we quantified polar bear activity (via collar‐mounted accelerometers) and body temperature (via loggers in the body core [Tabd] and periphery [Tper]) during 2–6 months of natural behavior, and during helicopter recapture and immobilization. Recapture induced bouts of peak activity higher than those that occurred during natural behavior for 2 of 5 bears, greater peak Tper for 3 of 6 bears, and greater peak Tabd for 1 of 6 bears. High body temperature (>39.0°C) occurred in Tper for 3 of 6 individuals during recapture and 6 of 6 individuals during natural behavior, and in Tabd for 2 of 6 individuals during recapture and 3 of 6 individuals during natural behavior. Measurements of Tabd and Tper correlated with rectal temperatures measured after immobilization, supporting the use of rectal temperatures for monitoring bear response to capture. Using a larger dataset (n = 66 captures), modeling of blood biochemistry revealed that maximum ambient temperature during recapture was associated with a stress leukogram (7–26% decline in percent lymphocytes, 12–21% increase in percent neutrophils) and maximum duration of helicopter operations had a similar but smaller effect. We conclude that polar bear activity and body temperature during helicopter capture are similar to that which occurs during the most intense events of natural behavior; high body temperature, especially in warm capture conditions, is a key concern; additional study of stress leukograms in polar bears is needed; and additional data collection regarding capture operations would be useful.
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Affiliation(s)
- John P. Whiteman
- Department of Biological Sciences, Old Dominion University Hampton Boulevard Norfolk VA 23529 USA
| | - Henry J. Harlow
- Department of Zoology and Physiology, University of Wyoming University Avenue Laramie WY 82071 USA
| | - George M. Durner
- Alaska Science Center, US Geological Survey University Drive Anchorage AK 99508 USA
| | - Eric V. Regehr
- Polar Science Center University of Washington NE 40th Street Seattle WA 98105 USA
| | | | - Anthony M. Pagano
- Alaska Science Center, US Geological Survey University Drive Anchorage AK 99508 USA
| | - Merav Ben‐David
- Department of Zoology and Physiology, University of Wyoming University Avenue Laramie WY 82071 USA
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4
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Wang MS, Murray GGR, Mann D, Groves P, Vershinina AO, Supple MA, Kapp JD, Corbett-Detig R, Crump SE, Stirling I, Laidre KL, Kunz M, Dalén L, Green RE, Shapiro B. A polar bear paleogenome reveals extensive ancient gene flow from polar bears into brown bears. Nat Ecol Evol 2022; 6:936-944. [PMID: 35711062 DOI: 10.1038/s41559-022-01753-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 03/30/2022] [Indexed: 11/09/2022]
Abstract
Polar bears (Ursus maritimus) and brown bears (Ursus arctos) are sister species possessing distinct physiological and behavioural adaptations that evolved over the last 500,000 years. However, comparative and population genomics analyses have revealed that several extant and extinct brown bear populations have relatively recent polar bear ancestry, probably as the result of geographically localized instances of gene flow from polar bears into brown bears. Here, we generate and analyse an approximate 20X paleogenome from an approximately 100,000-year-old polar bear that reveals a massive prehistoric admixture event, which is evident in the genomes of all living brown bears. This ancient admixture event was not visible from genomic data derived from living polar bears. Like more recent events, this massive admixture event mainly involved unidirectional gene flow from polar bears into brown bears and occurred as climate changes caused overlap in the ranges of the two species. These findings highlight the complex reticulate paths that evolution can take within a regime of radically shifting climate.
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Affiliation(s)
- Ming-Shan Wang
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Gemma G R Murray
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Daniel Mann
- Department of Geosciences, University of Alaska, Fairbanks, AK, USA.,Institute of Arctic Biology, University of Alaska, Fairbanks, AK, USA
| | - Pamela Groves
- Institute of Arctic Biology, University of Alaska, Fairbanks, AK, USA
| | - Alisa O Vershinina
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Megan A Supple
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Joshua D Kapp
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Russell Corbett-Detig
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Sarah E Crump
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Ian Stirling
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Wildlife Research Division, Environment and Climate Change Canada Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Kristin L Laidre
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Michael Kunz
- University of Alaska Museum of the North, Fairbanks, AK, USA
| | - Love Dalén
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden.,Centre for Palaeogenetics, Stockholm, Sweden
| | - Richard E Green
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Beth Shapiro
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, USA. .,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA.
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5
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Babiy UV, Salomashkina VV, Kulemeev PS, Kholodova MV, Gruzdev AR, Regehr EV. First evidence of a brown bear on Wrangel Island, Russia. URSUS 2022. [DOI: 10.2192/ursus-d-20-00024.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | | | | | | | | | - Eric V. Regehr
- Polar Science Center, University of Washington, Seattle, Washington, USA
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6
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Franz M, Whyte L, Atwood TC, Laidre KL, Roy D, Watson SE, Góngora E, McKinney MA. Distinct gut microbiomes in two polar bear subpopulations inhabiting different sea ice ecoregions. Sci Rep 2022; 12:522. [PMID: 35017585 PMCID: PMC8752607 DOI: 10.1038/s41598-021-04340-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/13/2021] [Indexed: 11/09/2022] Open
Abstract
Gut microbiomes were analyzed by 16S rRNA gene metabarcoding for polar bears (Ursus maritimus) from the southern Beaufort Sea (SB), where sea ice loss has led to increased use of land-based food resources by bears, and from East Greenland (EG), where persistent sea ice has allowed hunting of ice-associated prey nearly year-round. SB polar bears showed a higher number of total (940 vs. 742) and unique (387 vs. 189) amplicon sequence variants and higher inter-individual variation compared to EG polar bears. Gut microbiome composition differed significantly between the two subpopulations and among sex/age classes, likely driven by diet variation and ontogenetic shifts in the gut microbiome. Dietary tracer analysis using fatty acid signatures for SB polar bears showed that diet explained more intrapopulation variation in gut microbiome composition and diversity than other tested variables, i.e., sex/age class, body condition, and capture year. Substantial differences in the SB gut microbiome relative to EG polar bears, and associations between SB gut microbiome and diet, suggest that the shifting foraging habits of SB polar bears tied to sea ice loss may be altering their gut microbiome, with potential consequences for nutrition and physiology.
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Affiliation(s)
- Megan Franz
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Lyle Whyte
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Todd C Atwood
- United States Geological Survey (USGS), Alaska Science Center, University Drive, Anchorage, AK, 99508, USA
| | - Kristin L Laidre
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
- Greenland Institute of Natural Resources, P.O. Box 570, Nuuk, Greenland
| | - Denis Roy
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Sophie E Watson
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, UK
| | - Esteban Góngora
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada.
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7
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Atwood TC, Rode KD, Douglas DC, Simac K, Pagano AM, Bromaghin JF. Long-term variation in polar bear body condition and maternal investment relative to a changing environment. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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8
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Petherick AS, Reuther JD, Shirar SJ, Anderson SL, DeSantis LRG. Dietary ecology of Alaskan polar bears (Ursus maritimus) through time and in response to Arctic climate change. GLOBAL CHANGE BIOLOGY 2021; 27:3109-3119. [PMID: 33793039 DOI: 10.1111/gcb.15573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
Arctic climate change poses serious threats to polar bears (Ursus maritimus) as reduced sea ice makes seal prey inaccessible and marine ecosystems undergo bottom-up reorganization. Polar bears' elongated skulls and reduced molar dentition, as compared to their sister species the grizzly bear (Ursus arctos), are adaptations associated with hunting seals on sea ice and a soft, lipid-rich diet of blubber and meat. With significant declines in sea ice, it is unclear if and how polar bears may be altering their diets. Clarifying polar bear dietary responses to changing climates, both today and in the past, is critical to proper conservation and management of this apex predator. This is particularly important when a dietary strategy may be maladaptive. Here, we test the hypothesis that hard-food consumption (i.e., less preferred foods including bone), inferred from dental microwear texture analysis, increased with Arctic warming. We find that polar bears demonstrate a conserved absence of hard-object feeding in Alaska through time (including approximately 1000 years ago), until the 21st century, consistent with a highly conserved and specialized diet of soft blubber and flesh. Notably, our results also suggest that some 21st-century polar bears may be consuming harder foods (e.g., increased carcass utilization, terrestrial foods including garbage), despite having skulls and metabolisms poorly suited for such a diet. Prior to the 21st century, only polar bears with larger mandibles demonstrated increased hard-object feeding, though to a much lower degree than closely related grizzly bears which regularly consume mechanically challenging foods. Polar bears, being morphologically specialized, have biomechanical constraints which may limit their ability to consume mechanically challenging diets, with dietary shifts occurring only under the most extreme scenarios. Collectively, the highly specialized diets and cranial morphology of polar bears may severely limit their ability to adapt to a warming Arctic.
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Affiliation(s)
- Ansley S Petherick
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Joshua D Reuther
- Archaeology Department, University of Alaska Museum of the North, Fairbanks, AK, USA
- Department of Anthropology, University of Alaska, Fairbanks, AK, USA
| | - Scott J Shirar
- Archaeology Department, University of Alaska Museum of the North, Fairbanks, AK, USA
| | - Shelby L Anderson
- Department of Anthropology, Portland State University, Portland, OR, USA
| | - Larisa R G DeSantis
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA
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9
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Pagano AM, Williams TM. Physiological consequences of Arctic sea ice loss on large marine carnivores: unique responses by polar bears and narwhals. J Exp Biol 2021; 224:224/Suppl_1/jeb228049. [PMID: 33627459 DOI: 10.1242/jeb.228049] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Rapid environmental changes in the Arctic are threatening the survival of marine species that rely on the predictable presence of the sea ice. Two Arctic marine mammal specialists, the polar bear (Ursus maritimus) and narwhal (Monodon monoceros), appear especially vulnerable to the speed and capriciousness of sea ice deterioration as a consequence of their unique hunting behaviors and diet, as well as their physiological adaptations for slow-aerobic exercise. These intrinsic characteristics limit the ability of these species to respond to extrinsic threats associated with environmental change and increased industrial activity in a warming Arctic. In assessing how sea ice loss may differentially affect polar bears that hunt on the ice surface and narwhals that hunt at extreme depths below, we found that major ice loss translated into elevated locomotor costs that range from 3- to 4-fold greater than expected for both species. For polar bears this instigates an energy imbalance from the combined effects of reduced caloric intake and increased energy expenditure. For narwhals, high locomotor costs during diving increase the risk of ice entrapment due to the unreliability of breathing holes. These species-specific physiological constraints and extreme reliance on the polar sea ice conspire to make these two marine mammal specialists sentinels of climate change within the Arctic marine ecosystem that may foreshadow rapid changes to the marine ecosystem.
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Affiliation(s)
- Anthony M Pagano
- Institute for Conservation Research, San Diego Zoo Global, San Diego, CA 92027, USA
| | - Terrie M Williams
- University of California, Santa Cruz, Department of Ecology and Evolutionary Biology, Santa Cruz, CA 95060, USA
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10
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Bourque J, Desforges JP, Levin M, Atwood TC, Sonne C, Dietz R, Jensen TH, Curry E, McKinney MA. Climate-associated drivers of plasma cytokines and contaminant concentrations in Beaufort Sea polar bears (Ursus maritimus). THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 745:140978. [PMID: 32738684 DOI: 10.1016/j.scitotenv.2020.140978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/08/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Assessing polar bear (Ursus maritimus) immune function in relation to environmental stressors, including habitat change, nutritional stress, pathogen prevalence, and pollution, has been identified as critical for improved understanding of the species' health. The objectives of this study were two-fold: 1) to assess the role of climate-associated factors (habitat use, body condition) in explaining the plasma concentrations of contaminants in southern Beaufort Sea (SB) polar bears, and 2) to investigate how climate-associated factors, contaminant concentrations, and pathogen sero-prevalence influence the plasma concentrations of immune-signaling proteins called cytokines. A commercially available multiplex canine cytokine panel was validated for the quantification of five pro- and anti-inflammatory cytokines in polar bear plasma: tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), IL-8, IL-10, and interferon gamma-induced protein 10 (IP-10). This panel was then used to measure cytokine concentrations in 49 SB polar bears sampled in the springs of 2013 and 2014. Mean ∑PCBs (plasma), ∑OCs (plasma), and THg (hair) were 13.01 ± 1.52 ng g-1 w.w. (range: 0.17-52.63), 19.46 ± 1.17 ng g-1 w.w. (range: 6.63-45.82), and 0.49 μg g-1 d.w. (range: 0.99-15.18), respectively. Top models explaining variation in concentrations of plasma PCBs, plasma OC pesticides, and hair THg in SB polar bears included body mass index and/or habitat use (onshore versus offshore), with higher contaminant concentrations in leaner and/or offshore bears. Plasma cytokine concentrations were influenced most strongly by plasma PCBs and age, with little to no influence found for plasma OCs or hair THg concentrations, habitat use, or pathogen sero-prevalence. The lack of association between cytokines and these latter variables is likely due to a temporal disconnect between measured endpoints. The change of polar bear habitat use, feeding ecology, and body condition with ongoing climate warming is affecting exposure to contaminants and pathogens, with potential adverse consequences on a well-balanced immune system.
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Affiliation(s)
- Jennifer Bourque
- Wildlife and Fisheries Conservation Center, Department of Natural Resources and the Environment and Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, CT, USA
| | - Jean-Pierre Desforges
- Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Milton Levin
- Department of Pathobiology and Veterinary Sciences, University of Connecticut, Storrs, CT, USA
| | - Todd C Atwood
- US Geological Survey, Alaska Science Center, Anchorage, AK, USA
| | - Christian Sonne
- Department of Bioscience, Arctic Research Centre, Aarhus University, Roskilde 4000, Denmark
| | - Rune Dietz
- Department of Bioscience, Arctic Research Centre, Aarhus University, Roskilde 4000, Denmark
| | - Trine H Jensen
- Aalborg Zoo/Aalborg University, Mølleparkvej 63, 9000 Aalborg, Denmark
| | - Erin Curry
- Center for Conservation & Research of Endangered Wildlife, Cincinnati Zoo & Botanical Garden, Cincinnati, OH, USA
| | - Melissa A McKinney
- Wildlife and Fisheries Conservation Center, Department of Natural Resources and the Environment and Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, CT, USA; Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada.
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11
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Hayward KM, Harwood MP, Lougheed SC, Sun Z, Van Coeverden de Groot P, Jensen EL. A real-time PCR assay to accurately quantify polar bear DNA in fecal extracts. PeerJ 2020; 8:e8884. [PMID: 32292653 PMCID: PMC7147431 DOI: 10.7717/peerj.8884] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 03/11/2020] [Indexed: 11/20/2022] Open
Abstract
DNA extracted from fecal samples contains DNA from the focal species, food, bacteria and pathogens. Most DNA quantification methods measure total DNA and cannot differentiate among sources. Despite the desirability of noninvasive fecal sampling for studying wildlife populations, low amounts of focal species DNA make it difficult to use for next-generation sequencing (NGS), where accurate DNA quantification is critical for normalization. Two factors are required prior to using fecal samples in NGS libraries: (1) an accurate quantification method for the amount of target DNA and (2) a determination of the relative amount of target DNA needed for successful single nucleotide polymorphism genotyping assays. Here, we address these needs by developing primers to amplify a 101 bp region of the nuclear F2 gene and a quantitative PCR (qPCR) assay that allows the accurate quantification of the amount of polar bear (Ursus maritimus) DNA in fecal extracts. We test the assay on pure polar bear DNA extracted from muscle tissue and find a high correlation between fluorometric and qPCR quantifications. The qPCR assay was also successfully used to quantify the amount of DNA derived from polar bears in fecal extractions. Orthologs of the F2 gene have been identified across vertebrates; thus, similar qPCR assays could be developed for other species to enable noninvasive studies.
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Affiliation(s)
| | - Michelle P. Harwood
- Department of Biology, Queen’s University, Kingston, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | | | - Zhengxin Sun
- Department of Biology, Queen’s University, Kingston, ON, Canada
| | | | - Evelyn L. Jensen
- Department of Biology, Queen’s University, Kingston, ON, Canada
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
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12
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A phenological comparison of grizzly (Ursus arctos) and polar bears (Ursus maritimus) as waterfowl nest predators in Wapusk National Park. Polar Biol 2020. [DOI: 10.1007/s00300-020-02647-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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13
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Pagano AM, Atwood TC, Durner GM, Williams TM. The seasonal energetic landscape of an apex marine carnivore, the polar bear. Ecology 2020; 101:e02959. [DOI: 10.1002/ecy.2959] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/22/2019] [Accepted: 11/12/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Anthony M. Pagano
- U.S. Geological SurveyAlaska Science Center4210 University Drive Anchorage Alaska99508USA
- Department of Ecology & Evolutionary Biology University of California Santa Cruz 130 McAllister Way Santa Cruz California95060USA
| | - Todd C. Atwood
- U.S. Geological SurveyAlaska Science Center4210 University Drive Anchorage Alaska99508USA
| | - George M. Durner
- U.S. Geological SurveyAlaska Science Center4210 University Drive Anchorage Alaska99508USA
| | - Terrie M. Williams
- Department of Ecology & Evolutionary Biology University of California Santa Cruz 130 McAllister Way Santa Cruz California95060USA
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14
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Watson SE, Hauffe HC, Bull MJ, Atwood TC, McKinney MA, Pindo M, Perkins SE. Global change-driven use of onshore habitat impacts polar bear faecal microbiota. ISME JOURNAL 2019; 13:2916-2926. [PMID: 31378786 DOI: 10.1038/s41396-019-0480-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 07/04/2019] [Accepted: 07/11/2019] [Indexed: 12/16/2022]
Abstract
The gut microbiota plays a critical role in host health, yet remains poorly studied in wild species. Polar bears (Ursus maritimus), key indicators of Arctic ecosystem health and environmental change, are currently affected by rapid shifts in habitat that may alter gut homeostasis. Declining sea ice has led to a divide in the southern Beaufort Sea polar bear subpopulation such that an increasing proportion of individuals now inhabit onshore coastal regions during the open-water period ('onshore bears') while others continue to exhibit their typical behaviour of remaining on the ice ('offshore bears'). We propose that bears that have altered their habitat selection in response to climate change will exhibit a distinct gut microbiota diversity and composition, which may ultimately have important consequences for their health. Here, we perform the first assessment of abundance and diversity in the faecal microbiota of wild polar bears using 16S rRNA Illumina technology. We find that bacterial diversity is significantly higher in onshore bears compared to offshore bears. The most enriched OTU abundance in onshore bears belonged to the phylum Proteobacteria, while the most depleted OTU abundance within onshore bears was seen in the phylum Firmicutes. We conclude that climate-driven changes in polar bear land use are associated with distinct microbial communities. In doing so, we present the first case of global change mediated alterations in the gut microbiota of a free-roaming wild animal.
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Affiliation(s)
- Sophie E Watson
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, UK. .,Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all' Adige, TN, Italy.
| | - Heidi C Hauffe
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all' Adige, TN, Italy
| | - Matthew J Bull
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, UK.,Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all' Adige, TN, Italy
| | - Todd C Atwood
- United States Geological Survey (USGS), University Drive, Anchorage, AK, USA
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Massimo Pindo
- Department of Genomics and Biology of Fruit Crops, Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all' Adige, TN, Italy
| | - Sarah E Perkins
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, UK.,Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all' Adige, TN, Italy
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15
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Behaviour-Based Husbandry-A Holistic Approach to the Management of Abnormal Repetitive Behaviors. Animals (Basel) 2018; 8:ani8070103. [PMID: 29954148 PMCID: PMC6070902 DOI: 10.3390/ani8070103] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 06/21/2018] [Accepted: 06/23/2018] [Indexed: 12/24/2022] Open
Abstract
The field of zoo animal welfare science has developed significantly over recent years. However despite this progress in terms of scientific research, globally, zoo animals still face many welfare challenges. Recently, animal welfare frameworks such as the five domains or five needs have been developed and suggested to improve the welfare of zoo animals, but without practical guidance, such tools may remain abstract from the daily experience of zoo animals. Similarly specific practical strategies such as those for enrichment development exist, but their lack of holistic integration with other aspects of animal husbandry and behavioral medicine means that overall, good zoo animal welfare may still be lacking. This paper outlines some of the barriers to implementing improved zoo animal welfare in practice, and proposes a new strategy for the development of behavioral husbandry routines focused on the management and mitigation of abnormal repetitive behaviors. Focusing on enhancing zoo animal welfare by integrating aspects of ecology, ethology and clinical animal behavior into a practical and comprehensive approach to behavior-based husbandry.
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Environmental and behavioral changes may influence the exposure of an Arctic apex predator to pathogens and contaminants. Sci Rep 2017; 7:13193. [PMID: 29038498 PMCID: PMC5643432 DOI: 10.1038/s41598-017-13496-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/25/2017] [Indexed: 11/29/2022] Open
Abstract
Recent decline of sea ice habitat has coincided with increased use of land by polar bears (Ursus maritimus) from the southern Beaufort Sea (SB), which may alter the risks of exposure to pathogens and contaminants. We assayed blood samples from SB polar bears to assess prior exposure to the pathogens Brucella spp., Toxoplasma gondii, Coxiella burnetii, Francisella tularensis, and Neospora caninum, estimate concentrations of persistent organic pollutants (POPs), and evaluate risk factors associated with exposure to pathogens and POPs. We found that seroprevalence of Brucella spp. and T. gondii antibodies likely increased through time, and provide the first evidence of exposure of polar bears to C. burnetii, N. caninum, and F. tularensis. Additionally, the odds of exposure to T. gondii were greater for bears that used land than for bears that remained on the sea ice during summer and fall, while mean concentrations of the POP chlordane (ΣCHL) were lower for land-based bears. Changes in polar bear behavior brought about by climate-induced modifications to the Arctic marine ecosystem may increase exposure risk to certain pathogens and alter contaminant exposure pathways.
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Neuman‐Lee LA, Terletzky PA, Atwood TC, Gese EM, Smith GD, Greenfield S, Pettit J, French SS. Demographic and temporal variations in immunity and condition of polar bears (
Ursus maritimus
) from the southern Beaufort Sea. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2017; 327:333-346. [DOI: 10.1002/jez.2112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/27/2017] [Accepted: 08/29/2017] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Todd C. Atwood
- U.S. Geological Survey Alaska Science Center Anchorage Alaska
| | - Eric M. Gese
- Department of Wildland Resources Utah State University Logan Utah
- U.S. Department of Agriculture Wildlife Services National Wildlife Research Center Logan Utah
| | - Geoffrey D. Smith
- Department of Biological Sciences Dixie State University St. George Utah
| | | | - John Pettit
- Department of Biology Utah State University Logan Utah
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18
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Whiteman JP, Harlow HJ, Durner GM, Regehr EV, Rourke BC, Robles M, Amstrup SC, Ben-David M. Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer. CONSERVATION PHYSIOLOGY 2017; 5:cox049. [PMID: 28835844 PMCID: PMC5550809 DOI: 10.1093/conphys/cox049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 07/05/2017] [Accepted: 07/26/2017] [Indexed: 05/31/2023]
Abstract
When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April-May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these 'shore' bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These 'ice' bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt.
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Affiliation(s)
- John P. Whiteman
- Program in Ecology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, USA
- Department of Zoology and Physiology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, USA
| | - Henry J. Harlow
- Department of Zoology and Physiology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, USA
| | - George M. Durner
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA
| | - Eric V. Regehr
- Marine Mammals Management, U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, AK 99503, USA
- Current: Polar Science Center, Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, WA 98105, USA
| | - Bryan C. Rourke
- Department of Biological Sciences, California State University, 1250 Bellflower Blvd, Long Beach, CA 90840, USA
| | - Manuel Robles
- Department of Biological Sciences, California State University, 1250 Bellflower Blvd, Long Beach, CA 90840, USA
| | | | - Merav Ben-David
- Program in Ecology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, USA
- Department of Zoology and Physiology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, USA
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19
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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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20
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Newsome TM, Fleming PJS, Dickman CR, Doherty TS, Ripple WJ, Ritchie EG, Wirsing AJ. Making a New Dog? Bioscience 2017. [DOI: 10.1093/biosci/bix022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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21
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Implications of Rapid Environmental Change for Polar Bear Behavior and Sociality. MARINE MAMMAL WELFARE 2017. [DOI: 10.1007/978-3-319-46994-2_24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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22
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Galicia MP, Thiemann GW, Dyck MG, Ferguson SH, Higdon JW. Dietary habits of polar bears in Foxe Basin, Canada: possible evidence of a trophic regime shift mediated by a new top predator. Ecol Evol 2016; 6:6005-18. [PMID: 27547372 PMCID: PMC4983609 DOI: 10.1002/ece3.2173] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 04/05/2016] [Accepted: 04/13/2016] [Indexed: 11/09/2022] Open
Abstract
Polar bear (Ursus maritimus) subpopulations in several areas with seasonal sea ice regimes have shown declines in body condition, reproductive rates, or abundance as a result of declining sea ice habitat. In the Foxe Basin region of Nunavut, Canada, the size of the polar bear subpopulation has remained largely stable over the past 20 years, despite concurrent declines in sea ice habitat. We used fatty acid analysis to examine polar bear feeding habits in Foxe Basin and thus potentially identify ecological factors contributing to population stability. Adipose tissue samples were collected from 103 polar bears harvested during 2010-2012. Polar bear diet composition varied spatially within the region with ringed seal (Pusa hispida) comprising the primary prey in northern and southern Foxe Basin, whereas polar bears in Hudson Strait consumed equal proportions of ringed seal and harp seal (Pagophilus groenlandicus). Walrus (Odobenus rosmarus) consumption was highest in northern Foxe Basin, a trend driven by the ability of adult male bears to capture large-bodied prey. Importantly, bowhead whale (Balaena mysticetus) contributed to polar bear diets in all areas and all age and sex classes. Bowhead carcasses resulting from killer whale (Orcinus orca) predation and subsistence harvest potentially provide an important supplementary food source for polar bears during the ice-free period. Our results suggest that the increasing abundance of killer whales and bowhead whales in the region could be indirectly contributing to improved polar bear foraging success despite declining sea ice habitat. However, this indirect interaction between top predators may be temporary if continued sea ice declines eventually severely limit on-ice feeding opportunities for polar bears.
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Affiliation(s)
- Melissa P Galicia
- Department of Biology York University Toronto Ontario M3J 1P3 Canada
| | - Gregory W Thiemann
- Faculty of Environmental Studies York University Toronto Ontario M3J 1P3 Canada
| | - Markus G Dyck
- Wildlife Research Section Department of Environment Government of Nunavut P.O. Box 209 Igloolik Nunavut X0A 0L0 Canada
| | - Steven H Ferguson
- Fisheries and Oceans Canada 501 University Crescent Winnipeg Manitoba R3T 2N6 Canada
| | - Jeff W Higdon
- Higdon Wildlife Consulting 912 Ashburn Street Winnipeg Manitoba R3G 3C9 Canada
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23
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Pongracz JD, Derocher AE. Summer refugia of polar bears (Ursus maritimus) in the southern Beaufort Sea. Polar Biol 2016. [DOI: 10.1007/s00300-016-1997-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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24
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Atwood TC, Peacock E, McKinney MA, Lillie K, Wilson R, Douglas DC, Miller S, Terletzky P. Rapid Environmental Change Drives Increased Land Use by an Arctic Marine Predator. PLoS One 2016; 11:e0155932. [PMID: 27249673 PMCID: PMC4889047 DOI: 10.1371/journal.pone.0155932] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 05/06/2016] [Indexed: 11/18/2022] Open
Abstract
In the Arctic Ocean’s southern Beaufort Sea (SB), the length of the sea ice melt season (i.e., period between the onset of sea ice break-up in summer and freeze-up in fall) has increased substantially since the late 1990s. Historically, polar bears (Ursus maritimus) of the SB have mostly remained on the sea ice year-round (except for those that came ashore to den), but recent changes in the extent and phenology of sea ice habitat have coincided with evidence that use of terrestrial habitat is increasing. We characterized the spatial behavior of polar bears spending summer and fall on land along Alaska’s north coast to better understand the nexus between rapid environmental change and increased use of terrestrial habitat. We found that the percentage of radiocollared adult females from the SB subpopulation coming ashore has tripled over 15 years. Moreover, we detected trends of earlier arrival on shore, increased length of stay, and later departure back to sea ice, all of which were related to declines in the availability of sea ice habitat over the continental shelf and changes to sea ice phenology. Since the late 1990s, the mean duration of the open-water season in the SB increased by 36 days, and the mean length of stay on shore increased by 31 days. While on shore, the distribution of polar bears was influenced by the availability of scavenge subsidies in the form of subsistence-harvested bowhead whale (Balaena mysticetus) remains aggregated at sites along the coast. The declining spatio-temporal availability of sea ice habitat and increased availability of human-provisioned resources are likely to result in increased use of land. Increased residency on land is cause for concern given that, while there, bears may be exposed to a greater array of risk factors including those associated with increased human activities.
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Affiliation(s)
- Todd C. Atwood
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, United States of America
- * E-mail:
| | - Elizabeth Peacock
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, United States of America
| | - Melissa A. McKinney
- University of Connecticut, Center for Environmental Sciences and Engineering and Department of Natural Resources and the Environment, 1376 Storrs Road, Storrs, CT, 06269, United States of America
| | - Kate Lillie
- Utah State University, Department of Wildland Resources, Logan, UT, 84322–5230, United States of America
| | - Ryan Wilson
- U.S. Fish and Wildlife Service, Marine Mammals Management, 1011 E Tudor Road, Anchorage, AK, 99503, United States of America
| | - David C. Douglas
- U.S. Geological Survey, Alaska Science Center, 250 Egan Drive, Juneau, AK, 99801, United States of America
| | - Susanne Miller
- U.S. Fish and Wildlife Service, Marine Mammals Management, 1011 E Tudor Road, Anchorage, AK, 99503, United States of America
| | - Pat Terletzky
- Utah State University, Department of Wildland Resources, Logan, UT, 84322–5230, United States of America
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