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Fry TL, Friedrichs KR, Ketz AC, Duncan C, Van Deelen TR, Goldberg TL, Atwood TC. Long-term assessment of relationships between changing environmental conditions and the physiology of southern Beaufort Sea polar bears (Ursus maritimus). GLOBAL CHANGE BIOLOGY 2023; 29:5524-5539. [PMID: 37503782 DOI: 10.1111/gcb.16883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 06/28/2023] [Accepted: 06/30/2023] [Indexed: 07/29/2023]
Abstract
Climate change is influencing polar bear (Ursus maritimus) habitat, diet, and behavior but the effects of these changes on their physiology is not well understood. Blood-based biomarkers are used to assess the physiologic health of individuals but their usefulness for evaluating population health, especially as it relates to changing environmental conditions, has rarely been explored. We describe links between environmental conditions and physiologic functions of southern Beaufort Sea polar bears using data from blood samples collected from 1984 to 2018, a period marked by extensive environmental change. We evaluated associations between 13 physiologic biomarkers and circumpolar (Arctic oscillation index) and regional (wind patterns and ice-free days) environmental metrics and seasonal and demographic co-variates (age, sex, season, and year) known to affect polar bear ecology. We observed signs of dysregulation of water balance in polar bears following years with a lower annual Arctic oscillation index. In addition, liver enzyme values increased over time, which is suggestive of potential hepatocyte damage as the Arctic has warmed. Biomarkers of immune function increased with regional-scale wind patterns and the number of ice-free days over the Beaufort Sea continental shelf and were lower in years with a lower winter Arctic oscillation index, suggesting an increased allocation of energetic resources for immune processes under these conditions. We propose that the variation in polar bear immune and metabolic function is likely indicative of physiologic plasticity, a response that allows polar bears to remain in homeostasis even as they experience changes in nutrition and habitat in response to changing environments.
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Affiliation(s)
- Tricia L Fry
- School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | | | - Alison C Ketz
- Department of Forest and Wildlife Ecology, Wisconsin Cooperative Research Unit, University of Wisconsin, Madison, Wisconsin, USA
| | - Colleen Duncan
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Timothy R Van Deelen
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, Wisconsin, USA
| | - Tony L Goldberg
- School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Todd C Atwood
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA
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2
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Fry TL, Owens LA, Ketz AC, Atwood TC, Dunay E, Goldberg TL. Serum Virome of Southern Beaufort Sea polar bears ( Ursus maritimus) during a period of rapid climate change. CONSERVATION PHYSIOLOGY 2023; 11:coad054. [PMID: 39070777 PMCID: PMC10375943 DOI: 10.1093/conphys/coad054] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 06/02/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2024]
Abstract
Climate change affects the behavior, physiology and life history of many Arctic wildlife species. It can also influence the distribution and ecology of infectious agents. The southern Beaufort Sea (SB) subpopulation of polar bears (Ursus maritimus) has experienced dramatic behavioral changes due to retreating sea ice and other climate-related factors, but the effects of these changes on physiology and infection remain poorly understood. Using serum from polar bears sampled between 2004 and 2015 and metagenomic DNA sequencing, we identified 48 viruses, all of the family Anelloviridae. Anelloviruses are small, ubiquitous infectious agents with circular single-stranded DNA genomes that are not known to cause disease but, in humans, covary in diversity and load with immunological compromise. We therefore examined the usefulness of anelloviruses as biomarkers of polar bear physiological stress related to climate and habitat use. Polar bear anelloviruses sorted into two distinct clades on a phylogenetic tree, both of which also contained anelloviruses of giant pandas (Ailuropoda melanoleuca), another ursid. Neither anellovirus diversity nor load were associated with any demographic variables, behavioral factors or direct physiological measures. However, pairwise genetic distances between anelloviruses were positively correlated with pairwise differences in sampling date, suggesting that the polar bear "anellome" is evolving over time. These findings suggest that anelloviruses are not a sensitive indicator of polar physiological stress, but they do provide a baseline for evaluating future changes to polar bear viromes.
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Affiliation(s)
- Tricia L Fry
- School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53706
| | - Leah A Owens
- School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53706
| | - Alison C Ketz
- Wisconsin Cooperative Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI, 53706
| | - Todd C Atwood
- Alaska Science Center, U. S. Geological Survey, Anchorage, AK 99508
| | - Emily Dunay
- School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53706
| | - Tony L Goldberg
- School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53706
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3
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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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Grunst AS, Grunst ML, Grémillet D, Kato A, Bustamante P, Albert C, Brisson-Curadeau É, Clairbaux M, Cruz-Flores M, Gentès S, Perret S, Ste-Marie E, Wojczulanis-Jakubas K, Fort J. Mercury Contamination Challenges the Behavioral Response of a Keystone Species to Arctic Climate Change. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:2054-2063. [PMID: 36652233 DOI: 10.1021/acs.est.2c08893] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Combined effects of multiple, climate change-associated stressors are of mounting concern, especially in Arctic ecosystems. Elevated mercury (Hg) exposure in Arctic animals could affect behavioral responses to changes in foraging landscapes caused by climate change, generating interactive effects on behavior and population resilience. We investigated this hypothesis in little auks (Alle alle), a keystone Arctic seabird. We compiled behavioral data for 44 birds across 5 years using accelerometers while also quantifying blood Hg and environmental conditions. Warm sea surface temperature (SST) and low sea ice coverage reshaped time activity budgets (TABs) and diving patterns, causing decreased resting, increased flight, and longer dives. Mercury contamination was not associated with TABs. However, highly contaminated birds lengthened interdive breaks when making long dives, suggesting Hg-induced physiological limitations. As dive durations increased with warm SST, subtle toxicological effects threaten to increasingly constrain diving and foraging efficiency as climate change progresses, with ecosystem-wide repercussions.
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Affiliation(s)
- Andrea S Grunst
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle FR-17000, France
| | - Melissa L Grunst
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle FR-17000, France
| | - David Grémillet
- CEFE, UMR 5175, CNRS─Université de Montpellier─Université Paul-Valéry Montpellier─EPHE, Montpellier 34090, France
- Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Akiko Kato
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-La Rochelle Université, Villiers-en-Bois 79360, France
| | - Paco Bustamante
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle FR-17000, France
- Institut Universitaire de France (IUF), 1 rue Descartes, Paris 75005, France
| | - Céline Albert
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle FR-17000, France
| | - Émile Brisson-Curadeau
- McGill University─Macdonald Campus, 21111 Lakeshore Dr, Sainte-Anne-de-Bellevue, Quebec H9X 3V9, Canada
| | - Manon Clairbaux
- School of Biological, Environmental and Earth Sciences, University College Cork, Cork T23 N73K, Ireland
- MaREI Centre for Energy, Climate and Marine, Environmental Research Institute, University College Cork, Cork P43 C573, Ireland
| | - Marta Cruz-Flores
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle FR-17000, France
| | - Sophie Gentès
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle FR-17000, France
| | - Samuel Perret
- CEFE, UMR 5175, CNRS─Université de Montpellier─Université Paul-Valéry Montpellier─EPHE, Montpellier 34090, France
| | - Eric Ste-Marie
- McGill University─Macdonald Campus, 21111 Lakeshore Dr, Sainte-Anne-de-Bellevue, Quebec H9X 3V9, Canada
| | | | - Jérôme Fort
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle FR-17000, France
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5
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Kellner A, Atwood TC, Douglas DC, Breck SW, Wittemyer G. High winds and melting sea ice trigger landward movement in a polar bear population of concern. Ecosphere 2023. [DOI: 10.1002/ecs2.4420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Annie Kellner
- Graduate Degree Program in Ecology Colorado State University Fort Collins Colorado USA
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
| | - Todd C. Atwood
- U.S. Geological Survey Alaska Science Center Anchorage Alaska USA
| | | | - Stewart W. Breck
- USDA‐WS‐National Wildlife Research Center Fort Collins Colorado USA
| | - George Wittemyer
- Graduate Degree Program in Ecology Colorado State University Fort Collins Colorado USA
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
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6
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Wilder JM, Mangipane LS, Atwood T, Kochnev A, Smith T, Vongraven D. Efficacy of bear spray as a deterrent against polar bears. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- James M. Wilder
- U.S. Fish and Wildlife Service, Marine Mammals Management 1011 E. Tudor Road Anchorage AK 99503 USA
| | - Lindsey S. Mangipane
- U.S. Fish and Wildlife Service, Marine Mammals Management 1011 E. Tudor Road Anchorage AK 99503 USA
| | - Todd Atwood
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive Anchorage Alaska 99508 USA
| | - 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
- Beringia National Park, 10 Naberezhnaya Dezhneva 89251 Provideniya Russia
| | - Tom Smith
- Wildlife and Wildlands Conservation Program Brigham Young University 5050 Life Sciences Building Provo Utah 84602 USA
| | - Dag Vongraven
- Norwegian Polar Institute, Fram Center N‐9296 Tromsø Norway
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7
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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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8
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Borgå K, McKinney MA, Routti H, Fernie KJ, Giebichenstein J, Hallanger I, Muir DCG. The influence of global climate change on accumulation and toxicity of persistent organic pollutants and chemicals of emerging concern in Arctic food webs. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:1544-1576. [PMID: 35179539 DOI: 10.1039/d1em00469g] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This review summarizes current understanding of how climate change-driven physical and ecological processes influence the levels of persistent organic pollutants (POPs) and contaminants of emerging Arctic concern (CEACs) in Arctic biota and food webs. The review also highlights how climate change may interact with other stressors to impact contaminant toxicity, and the utility of modeling and newer research tools in closing knowledge gaps on climate change-contaminant interactions. Permafrost thaw is influencing the concentrations of POPs in freshwater ecosystems. Physical climate parameters, including climate oscillation indices, precipitation, water salinity, sea ice age, and sea ice quality show statistical associations with POPs concentrations in multiple Arctic biota. Northward range-shifting species can act as biovectors for POPs and CEACs into Arctic marine food webs. Shifts in trophic position can alter POPs concentrations in populations of Arctic species. Reductions in body condition are associated with increases in levels of POPs in some biota. Although collectively understudied, multiple stressors, including contaminants and climate change, may act to cumulatively impact some populations of Arctic biota. Models are useful for predicting the net result of various contrasting climate-driven processes on POP and CEAC exposures; however, for some parameters, especially food web changes, insufficient data exists with which to populate such models. In addition to the impact of global regulations on POP levels in Arctic biota, this review demonstrates that there are various direct and indirect mechanisms by which climate change can influence contaminant exposure, accumulation, and effects; therefore, it is important to attribute POP variations to the actual contributing factors to inform future regulations and policies. To do so, a broad range of habitats, species, and processes must be considered for a thorough understanding and interpretation of the consequences to the distribution, accumulation, and effects of environmental contaminants. Given the complex interactions between climate change, contaminants, and ecosystems, it is important to plan for long-term, integrated pan-Arctic monitoring of key biota and ecosystems, and to collect ancillary data, including information on climate-related parameters, local meteorology, ecology, and physiology, and when possible, behavior, when carrying out research on POPs and CEACs in biota and food webs of the Arctic.
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Affiliation(s)
- Katrine Borgå
- Department of Biosciences, University of Oslo, NO-0316 Oslo, Norway.
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3 V9, Canada.
| | - Heli Routti
- Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway
| | - Kim J Fernie
- Ecotoxicology & Wildlife Health, Environment and Climate Change Canada, Burlington, ON, L7S 1A1, Canada
| | | | | | - Derek C G Muir
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON, L7S 1A1, Canada
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9
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A SEROLOGIC SURVEY OF FRANCISELLA TULARENSIS EXPOSURE IN WILDLIFE ON THE ARCTIC COASTAL PLAIN OF ALASKA, USA. J Wildl Dis 2022; 58:746-755. [PMID: 36302352 DOI: 10.7589/jwd-d-21-00162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 06/29/2022] [Indexed: 12/03/2022]
Abstract
Tularemia is an infectious zoonotic disease caused by one of several subspecies of Francisella tularensis bacteria. Infections by F. tularensis are common throughout the northern hemisphere and have been detected in more than 250 wildlife species. In Alaska, US, where the pathogen was first identified in 1938, studies have identified F. tularensis antibodies in a diverse suite of taxa, including insects, birds, and mammals. However, few such investigations have been conducted recently and knowledge about the current distribution and disease ecology of F. tularensis is limited, particularly in Arctic Alaska, an area undergoing rapid environmental changes from climate warming. To help address these information gaps and provide insights about patterns of exposure among wildlife, we assessed the seroprevalence of F. tularensis antibodies in mammals and tundra-nesting geese from the Arctic Coastal Plain of Alaska, 2014-17. With a commercially available slide agglutination test, we detected antibodies in 14.7% of all individuals sampled (n=722), with titers ranging from 1:20 to 1:320. We detected significant differences in seroprevalence between family groups, with Canidae (foxes, Vulpes spp.) and Sciuridae (Arctic ground squirrel, Spermophilus parryii) having the highest seroprevalence at 21.5% and 33.3%, respectively. Mean seroprevalence for Ursidae (polar bears, Ursus maritimus) was 13.3%, whereas Cervidae (caribou, Rangifer tarandus) had comparatively low seroprevalence at 6.5%. Antibodies were detected in all Anatidae species sampled, with Black Brant (Branta bernicla nigricans) having the highest seroprevalence at 13.6%. The detection of F. tularensis antibodies across multiple taxa from the Arctic Coastal Plain and its nearshore marine region provides evidence of exposure to this pathogen throughout the region and highlights the need for renewed surveillance in Alaska.
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10
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Patil VP, Durner GM, Douglas DC, Atwood TC. Modeling the spatial and temporal dynamics of land‐based polar bear denning in Alaska. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Vijay P. Patil
- Alaska Science Center U.S. Geological Survey 4210 University Drive Anchorage AK 99508 USA
| | - George M. Durner
- Alaska Science Center U.S. Geological Survey 4210 University Drive Anchorage AK 99508 USA
| | - David C. Douglas
- Alaska Science Center U.S. Geological Survey 250 Egan Drive Juneau AK 99801 USA
| | - Todd C. Atwood
- Alaska Science Center U.S. Geological Survey 4210 University Drive Anchorage AK 99508 USA
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11
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McKinney MA, Chételat J, Burke SM, Elliott KH, Fernie KJ, Houde M, Kahilainen KK, Letcher RJ, Morris AD, Muir DCG, Routti H, Yurkowski DJ. Climate change and mercury in the Arctic: Biotic interactions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155221. [PMID: 35427623 DOI: 10.1016/j.scitotenv.2022.155221] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/18/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
Global climate change has led to profound alterations of the Arctic environment and ecosystems, with potential secondary effects on mercury (Hg) within Arctic biota. This review presents the current scientific evidence for impacts of direct physical climate change and indirect ecosystem change on Hg exposure and accumulation in Arctic terrestrial, freshwater, and marine organisms. As the marine environment is elevated in Hg compared to the terrestrial environment, terrestrial herbivores that now exploit coastal/marine foods when terrestrial plants are iced over may be exposed to higher Hg concentrations. Conversely, certain populations of predators, including Arctic foxes and polar bears, have shown lower Hg concentrations related to reduced sea ice-based foraging and increased land-based foraging. How climate change influences Hg in Arctic freshwater fishes is not clear, but for lacustrine populations it may depend on lake-specific conditions, including interrelated alterations in lake ice duration, turbidity, food web length and energy sources (benthic to pelagic), and growth dilution. In several marine mammal and seabird species, tissue Hg concentrations have shown correlations with climate and weather variables, including climate oscillation indices and sea ice trends; these findings suggest that wind, precipitation, and cryosphere changes that alter Hg transport and deposition are impacting Hg concentrations in Arctic marine organisms. Ecological changes, including northward range shifts of sub-Arctic species and altered body condition, have also been shown to affect Hg levels in some populations of Arctic marine species. Given the limited number of populations and species studied to date, especially within Arctic terrestrial and freshwater systems, further research is needed on climate-driven processes influencing Hg concentrations in Arctic ecosystems and their net effects. Long-term pan-Arctic monitoring programs should consider ancillary datasets on climate, weather, organism ecology and physiology to improve interpretation of spatial variation and time trends of Hg in Arctic biota.
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Affiliation(s)
- Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3 V9, Canada.
| | - John Chételat
- Ecotoxicology & Wildlife Health, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada
| | - Samantha M Burke
- Minnow Aquatic Environmental Services, Guelph, ON N1H 1E9, Canada
| | - Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3 V9, Canada
| | - Kim J Fernie
- Ecotoxicology & Wildlife Health, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
| | - Magali Houde
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Montréal, QC H2Y 5E7, Canada
| | - Kimmo K Kahilainen
- Lammi Biological Station, University of Helsinki, FI-16900 Lammi, Finland
| | - Robert J Letcher
- Ecotoxicology & Wildlife Health, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada
| | - Adam D Morris
- Northern Contaminants Program, Crown-Indigenous Relations and Northern Affairs Canada, Gatineau, QC J8X 2V6, Canada
| | - Derek C G Muir
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
| | - Heli Routti
- Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway
| | - David J Yurkowski
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, Winnipeg, MB R3T 2N6, Canada
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12
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Griffen BD, Whiteman JP, Pullan S. Significance of autumn and winter food consumption for reproduction by Southern Beaufort Sea polar bears, Ursus maritimus. Polar Biol 2022. [DOI: 10.1007/s00300-022-03066-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
AbstractPolar bears (Ursus maritimus) in the southern Beaufort Sea experience long annual periods when preferred seal prey are scarce or are unavailable. Consumption of bowhead whale (Balaena mysticetus) carcasses from native Alaskan subsistence hunting is increasingly common for onshore polar bears, yet the energetic consequences of this consumption remain unclear. We use data on bears captured repeatedly over periods that encompassed autumn and winter, combined with calculations, to show that adult female bears likely consume an average of at least 4 seal equivalents during both autumn and winter periods and that considerable variation in energy intake exists across individual bears. We further show that subsistence-caught whale carcasses provide an upper threshold of > 4000 seal equivalents, which could potentially meet mean consumption needs of ~ 80% of the southern Beaufort Sea bear subpopulation during autumn and winter periods. Finally, we modify an existing model to show that observed mass changes over autumn and winter could substantially alter spring foraging habitat choice by females with cubs and the chance that a female with reduced energy reserves would abort a pregnancy or abandon cubs in favor of increasing her own survival; these behaviors could potentially influence population vital rates. Our study highlights the importance of mass dynamics over the autumn and winter months, points to the need for additional data on foraging and energetics over this period, and indicates that the recent declines in polar bear body condition in some subpopulations could have complex effects on reproduction.
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13
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Wilson RR, Martin MS, Regehr EV, Rode KD. Intrapopulation differences in polar bear movement and step selection patterns. MOVEMENT ECOLOGY 2022; 10:25. [PMID: 35606849 PMCID: PMC9128121 DOI: 10.1186/s40462-022-00326-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 05/14/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The spatial ecology of individuals often varies within a population or species. Identifying how individuals in different classes interact with their environment can lead to a better understanding of population responses to human activities and environmental change and improve population estimates. Most inferences about polar bear (Ursus maritimus) spatial ecology are based on data from adult females due to morphological constraints on applying satellite radio collars to other classes of bears. Recent studies, however, have provided limited movement data for adult males and sub-adults of both sexes using ear-mounted and glue-on tags. We evaluated class-specific movements and step selection patterns for polar bears in the Chukchi Sea subpopulation during spring. METHODS We developed hierarchical Bayesian models to evaluate polar bear movement (i.e., step length and directional persistence) and step selection at the scale of 4-day step lengths. We assessed differences in movement and step selection parameters among the three classes of polar bears (i.e., adult males, sub-adults, and adult females without cubs-of-the-year). RESULTS Adult males had larger step lengths and less directed movements than adult females. Sub-adult movement parameters did not differ from the other classes but point estimates were most similar to adult females. We did not detect differences among polar bear classes in step selection parameters and parameter estimates were consistent with previous studies. CONCLUSIONS Our findings support the use of estimated step selection patterns from adult females as a proxy for other classes of polar bears during spring. Conversely, movement analyses indicated that using data from adult females as a proxy for the movements of adult males is likely inappropriate. We recommend that researchers consider whether it is valid to extend inference derived from adult female movements to other classes, based on the questions being asked and the spatial and temporal scope of the data. Because our data were specific to spring, these findings highlight the need to evaluate differences in movement and step selection during other periods of the year, for which data from ear-mounted and glue-on tags are currently lacking.
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Affiliation(s)
- Ryan R Wilson
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK, USA.
| | - Michelle St Martin
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK, USA
- U.S. Fish and Wildlife Service, Portland, OR, 97266, USA
| | - Eric V Regehr
- Polar Science Center, University of Washington, Seattle, WA, USA
| | - Karyn D Rode
- U.S. Geological Survey, Alaska Science Center, Anchorage, AK, USA
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14
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Hamilton CD, Lydersen C, Aars J, Acquarone M, Atwood T, Baylis A, Biuw M, Boltunov AN, Born EW, Boveng P, Brown TM, Cameron M, Citta J, Crawford J, Dietz R, Elias J, Ferguson SH, Fisk A, Folkow LP, Frost KJ, Glazov DM, Granquist SM, Gryba R, Harwood L, Haug T, Heide‐Jørgensen MP, Hussey NE, Kalinek J, Laidre KL, Litovka DI, London JM, Loseto LL, MacPhee S, Marcoux M, Matthews CJD, Nilssen K, Nordøy ES, O’Corry‐Crowe G, Øien N, Olsen MT, Quakenbush L, Rosing‐Asvid A, Semenova V, Shelden KEW, Shpak OV, Stenson G, Storrie L, Sveegaard S, Teilmann J, Ugarte F, Von Duyke AL, Watt C, Wiig Ø, Wilson RR, Yurkowski DJ, Kovacs KM. Marine mammal hotspots across the circumpolar Arctic. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13543] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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15
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Mayette A, Loseto L, Pearce T, Hornby C, Marcoux M. Group characteristics and spatial organization of the Eastern Beaufort Sea beluga whale (Delphinapterus leucas) population using aerial photographs. CAN J ZOOL 2022. [DOI: 10.1139/cjz-2021-0232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
While it is known that beluga whales (Delphinapterus leucas (Pallas, 1776)) are social animals, sociality within populations remains complex and poorly understood. Using aerial photographs taken in mid-July and early August 2019, we examined group characteristics and spatial organization of the Eastern Beaufort Sea beluga population in two distinct summering areas: (1) the continental shelf and offshore region of the southeast Beaufort Sea, and (2) the inshore of the Mackenzie Estuary. Observations revealed that the average group size was similar in both environments. A piecewise regression analysis showed that belugas were found to be most frequently within 24.6 m of another beluga in the offshore, and within 22.0 m in the inshore. The average inter-individual distance of groups composed of subadults and/or adults was greater than that of groups including younger whales in both environments. Also, the swimming direction of individuals in a group differed less in the offshore than in the inshore. We suggest that habitat shapes the types of activity conducted and that spatial cohesion within groups persists across environmental conditions but changes with age composition. By identifying elements of social structure and important areas for Eastern Beaufort Sea belugas, our results highlight the value of habitat conservation.
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Affiliation(s)
- Alexandra Mayette
- University of Manitoba Clayton H Riddell Faculty of Environment Earth and Resources, 194380, Centre for Earth Observation Science (CEOS), Winnipeg, Manitoba, Canada
| | - Lisa Loseto
- University of Manitoba Clayton H Riddell Faculty of Environment Earth and Resources, 194380, Centre for Earth Observation Science (CEOS), Winnipeg, Manitoba, Canada
- Fisheries and Oceans Canada Central and Arctic Region, 111145, Winnipeg, Manitoba, Canada
| | - Tristan Pearce
- University of Northern British Columbia, 6727, Department of Global & International Studies Natural Resources and Environmental Studies, Prince George, British Columbia, Canada, V2N 4Z9
| | - Claire Hornby
- Fisheries and Oceans Canada Central and Arctic Region, 111145, Winnipeg, Manitoba, Canada
| | - Marianne Marcoux
- Fisheries and Oceans Canada Central and Arctic Region, 111145, Winnipeg, Manitoba, Canada
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16
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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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17
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Woodruff SP, Andersen EM, Wilson RR, Mangipane LS, Miller SB, Klein KJ, Lemons PR. Classifying the effects of human disturbance on denning polar bears. ENDANGER SPECIES RES 2022. [DOI: 10.3354/esr01203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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, 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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19
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Pagano AM, Durner GM, Atwood TC, Douglas DC. Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea. Ecosphere 2021. [DOI: 10.1002/ecs2.3768] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Anthony M. Pagano
- U.S. Geological Survey Alaska Science Center Anchorage Alaska 99508 USA
| | - George M. Durner
- U.S. Geological Survey Alaska Science Center Anchorage Alaska 99508 USA
| | - Todd C. Atwood
- U.S. Geological Survey Alaska Science Center Anchorage Alaska 99508 USA
| | - David C. Douglas
- U.S. Geological Survey Alaska Science Center Juneau Alaska 99801 USA
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20
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Pilfold NW, Richardson ES, Ellis J, Jenkins E, Scandrett WB, Hernández‐Ortiz A, Buhler K, McGeachy D, Al‐Adhami B, Konecsni K, Lobanov VA, Owen MA, Rideout B, Lunn NJ. Long-term increases in pathogen seroprevalence in polar bears (Ursus maritimus) influenced by climate change. GLOBAL CHANGE BIOLOGY 2021; 27:4481-4497. [PMID: 34292654 PMCID: PMC8457125 DOI: 10.1111/gcb.15537] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 12/28/2020] [Indexed: 05/10/2023]
Abstract
The influence of climate change on wildlife disease dynamics is a burgeoning conservation and human health issue, but few long-term studies empirically link climate to pathogen prevalence. Polar bears (Ursus maritimus) are vulnerable to the negative impacts of sea ice loss as a result of accelerated Arctic warming. While studies have associated changes in polar bear body condition, reproductive output, survival, and abundance to reductions in sea ice, no long-term studies have documented the impact of climate change on pathogen exposure. We examined 425 serum samples from 381 adult polar bears, collected in western Hudson Bay (WH), Canada, for antibodies to selected pathogens across three time periods: 1986-1989 (n = 157), 1995-1998 (n = 159) and 2015-2017 (n = 109). We ran serological assays for antibodies to seven pathogens: Toxoplasma gondii, Neospora caninum, Trichinella spp., Francisella tularensis, Bordetella bronchiseptica, canine morbillivirus (CDV) and canine parvovirus (CPV). Seroprevalence of zoonotic parasites (T. gondii, Trichinella spp.) and bacterial pathogens (F. tularensis, B. bronchiseptica) increased significantly between 1986-1989 and 1995-1998, ranging from +6.2% to +20.8%, with T. gondii continuing to increase into 2015-2017 (+25.8% overall). Seroprevalence of viral pathogens (CDV, CPV) and N. caninum did not change with time. Toxoplasma gondii seroprevalence was higher following wetter summers, while seroprevalences of Trichinella spp. and B. bronchiseptica were positively correlated with hotter summers. Seroprevalence of antibodies to F. tularensis increased following years polar bears spent more days on land, and polar bears previously captured in human settlements were more likely to be seropositive for Trichinella spp. As the Arctic has warmed due to climate change, zoonotic pathogen exposure in WH polar bears has increased, driven by numerous altered ecosystem pathways.
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Affiliation(s)
- Nicholas W. Pilfold
- Conservation Science and Wildlife HealthSan Diego Zoo Wildlife AllianceEscondidoCAUSA
| | - Evan S. Richardson
- Wildlife Research Division, Science and Technology BranchEnvironment and Climate Change CanadaWinnipegMBCanada
| | - John Ellis
- Department of Veterinary MicrobiologyUniversity of SaskatchewanSaskatoonSKCanada
| | - Emily Jenkins
- Department of Veterinary MicrobiologyUniversity of SaskatchewanSaskatoonSKCanada
| | - W. Brad Scandrett
- Centre for Food‐borne and Animal ParasitologyCanadian Food Inspection AgencySaskatoonSKCanada
| | | | - Kayla Buhler
- Department of Veterinary MicrobiologyUniversity of SaskatchewanSaskatoonSKCanada
| | - David McGeachy
- Wildlife Research Division, Science and Technology BranchEnvironment and Climate Change CanadaEdmontonABCanada
| | - Batol Al‐Adhami
- Centre for Food‐borne and Animal ParasitologyCanadian Food Inspection AgencySaskatoonSKCanada
| | - Kelly Konecsni
- Centre for Food‐borne and Animal ParasitologyCanadian Food Inspection AgencySaskatoonSKCanada
| | - Vladislav A. Lobanov
- Centre for Food‐borne and Animal ParasitologyCanadian Food Inspection AgencySaskatoonSKCanada
| | - Megan A. Owen
- Conservation Science and Wildlife HealthSan Diego Zoo Wildlife AllianceEscondidoCAUSA
| | - Bruce Rideout
- Conservation Science and Wildlife HealthSan Diego Zoo Wildlife AllianceEscondidoCAUSA
| | - Nicholas J. Lunn
- Wildlife Research Division, Science and Technology BranchEnvironment and Climate Change CanadaEdmontonABCanada
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21
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Bromaghin JF, Douglas DC, Durner GM, Simac KS, Atwood TC. Survival and abundance of polar bears in Alaska's Beaufort Sea, 2001-2016. Ecol Evol 2021; 11:14250-14267. [PMID: 34707852 PMCID: PMC8525099 DOI: 10.1002/ece3.8139] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 08/02/2021] [Accepted: 09/06/2021] [Indexed: 12/20/2022] Open
Abstract
The Arctic Ocean is undergoing rapid transformation toward a seasonally ice-free ecosystem. As ice-adapted apex predators, polar bears (Ursus maritimus) are challenged to cope with ongoing habitat degradation and changes in their prey base driven by food-web response to climate warming. Knowledge of polar bear response to environmental change is necessary to understand ecosystem dynamics and inform conservation decisions. In the southern Beaufort Sea (SBS) of Alaska and western Canada, sea ice extent has declined since satellite observations began in 1979 and available evidence suggests that the carrying capacity of the SBS for polar bears has trended lower for nearly two decades. In this study, we investigated the population dynamics of polar bears in Alaska's SBS from 2001 to 2016 using a multistate Cormack-Jolly-Seber mark-recapture model. States were defined as geographic regions, and we used location data from mark-recapture observations and satellite-telemetered bears to model transitions between states and thereby explain heterogeneity in recapture probabilities. Our results corroborate prior findings that the SBS subpopulation experienced low survival from 2003 to 2006. Survival improved modestly from 2006 to 2008 and afterward rebounded to comparatively high levels for the remainder of the study, except in 2012. Abundance moved in concert with survival throughout the study period, declining substantially from 2003 and 2006 and afterward fluctuating with lower variation around an average of 565 bears (95% Bayesian credible interval [340, 920]) through 2015. Even though abundance was comparatively stable and without sustained trend from 2006 to 2015, polar bears in the Alaska SBS were less abundant over that period than at any time since passage of the U.S. Marine Mammal Protection Act. The potential for recovery is likely limited by the degree of habitat degradation the subpopulation has experienced, and future reductions in carrying capacity are expected given current projections for continued climate warming.
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Affiliation(s)
| | | | | | | | - Todd C. Atwood
- U.S. Geological SurveyAlaska Science CenterAnchorageAKUSA
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22
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Rode KD, Robbins CT, Stricker CA, Taras BD, Tollefson TN. Energetic and health effects of protein overconsumption constrain dietary adaptation in an apex predator. Sci Rep 2021; 11:15309. [PMID: 34321600 PMCID: PMC8319126 DOI: 10.1038/s41598-021-94917-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 07/19/2021] [Indexed: 12/02/2022] Open
Abstract
Studies of predator feeding ecology commonly focus on energy intake. However, captive predators have been documented to selectively feed to optimize macronutrient intake. As many apex predators experience environmental changes that affect prey availability, limitations on selective feeding can affect energetics and health. We estimated the protein:fat ratio of diets consumed by wild polar bears using a novel isotope-based approach, measured protein:fat ratios selected by zoo polar bears offered dietary choice and examined potential energetic and health consequences of overconsuming protein. Dietary protein levels selected by wild and zoo polar bears were low and similar to selection observed in omnivorous brown bears, which reduced energy intake requirements by 70% compared with lean meat diets. Higher-protein diets fed to zoo polar bears during normal care were concurrent with high rates of mortality from kidney disease and liver cancer. Our results suggest that polar bears have low protein requirements and that limitations on selective consumption of marine mammal blubber consequent to climate change could meaningfully increase their energetic costs. Although bear protein requirements appear lower than those of other carnivores, the energetic and health consequences of protein overconsumption identified in this study have the potential to affect a wide range of taxa.
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Affiliation(s)
- Karyn D Rode
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA.
| | - Charles T Robbins
- School of the Environment and School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Craig A Stricker
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, CO, 80526, USA
| | - Brian D Taras
- Division of Wildlife Conservation, Alaska Department of Fish and Game, Fairbanks, AK, 99701, USA
| | - Troy N Tollefson
- Mazuri Exotic Animal Nutrition, Land O'Lakes, Inc., St. Louis, MO, 63166, USA
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23
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Lomac-MacNair K, Wisdom S, Pedro De Andrade J, Stepanuk JE, Esteves E. Polar bear behavioral response to vessel surveys in northeastern Chukchi Sea, 2008–2014. URSUS 2021. [DOI: 10.2192/ursus-d-20-00023.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Kate Lomac-MacNair
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve Campus de Gambelas, 8005-139 Faro, Portugal
| | - Sheyna Wisdom
- Fairweather Science LLC, 301 Calista Court, Anchorage, AK 99518, USA
| | - José Pedro De Andrade
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve Campus de Gambelas, 8005-139 Faro, Portugal
| | - Julia E. Stepanuk
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794, USA
| | - Eduardo Esteves
- CCMAR, Centro de Ciências do Mar and Instituto Superior de Engenharia, Universidade do Algarve Campus da Penha, 8005-139 Faro, Portugal
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24
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Bohart AM, Lunn NJ, Derocher AE, McGeachy D. Migration dynamics of polar bears ( Ursus maritimus) in western Hudson Bay. Behav Ecol 2021. [DOI: 10.1093/beheco/araa140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Migration is predicted to change both spatially and temporally as climate change alters seasonal resource availability. Species in extreme environments are especially susceptible to climate change; hence, it is important to determine environmental and biological variables that influence their migration. Polar bears (Ursus maritimus) are an Arctic apex carnivore whose migration phenology has been affected by climate change and is vulnerable to future changes. Here, we used satellite-linked telemetry collar data from adult female polar bears in western Hudson Bay from 2004 to 2016 and multivariate response regression models to demonstrate that 1) spatial and temporal migration metrics are correlated, 2) ice concentration and wind are important environmental variables that influence polar bear migration in seasonal ice areas, and 3) migration did not vary across the years of our study, highlighting the importance of continued monitoring. Specifically, we found that ice concentration, wind speed, and wind direction affected polar bear migration onto ice during freeze-up and ice concentration and wind direction affected migration onto land during breakup. Bears departed from land earlier with increased wind speed and the effect of wind direction on migration may be linked to prey searching and ice drift. Low ice concentration was associated with higher movement during freeze-up and breakup. Our findings suggest that migration movement may increase in response to climate change as ice concentration and access to prey declines, potentially increasing nutritional stress on bears.
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Affiliation(s)
- Alyssa M Bohart
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Nicholas J Lunn
- Wildlife Research Division, Science and Technology Branch, Environment and Climate Change Canada, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew E Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - David McGeachy
- Wildlife Research Division, Science and Technology Branch, Environment and Climate Change Canada, University of Alberta, Edmonton, Alberta, Canada
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25
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Rode KD, Regehr EV, Bromaghin JF, Wilson RR, St Martin M, Crawford JA, Quakenbush LT. Seal body condition and atmospheric circulation patterns influence polar bear body condition, recruitment, and feeding ecology in the Chukchi Sea. GLOBAL CHANGE BIOLOGY 2021; 27:2684-2701. [PMID: 33644944 DOI: 10.1111/gcb.15572] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/10/2021] [Indexed: 06/12/2023]
Abstract
Polar bears (Ursus maritimus) are experiencing loss of sea ice habitats used to access their marine mammal prey. Simultaneously, ocean warming is changing ecosystems that support marine mammal populations. The interactive effects of sea ice and prey are not well understood yet may explain spatial-temporal variation in the response of polar bears to sea ice loss. Here, we examined the potential combined effects of sea ice, seal body condition, and atmospheric circulation patterns on the body condition, recruitment, diet, and feeding probability of 469 polar bears captured in the Chukchi Sea, 2008-2017. The body condition of ringed seals (Pusa hispida), the primary prey of females and subadults, was related to dietary proportions of ringed seal, feeding probability, and the body condition of females and cubs. In contrast, adult males consumed more bearded seals (Erignathus barbatus) and exhibited better condition when bearded seal body condition was higher. The litter size, number of yearlings per adult female, and the condition of dependent young were higher following winters characterized by low Arctic Oscillation conditions, consistent with a growing number of studies. Body condition, recruitment, and feeding probability were either not associated or negatively associated with sea ice conditions, suggesting that, unlike some subpopulations, Chukchi Sea bears are not currently limited by sea ice availability. However, spring sea ice cover declined 2% per year during our study reaching levels not previously observed in the satellite record and resulting in the loss of polar bear hunting and seal pupping habitat. Our study suggests that the status of ice seal populations is likely an important factor that can either compound or mitigate the response of polar bears to sea ice loss over the short term. In the long term, neither polar bears nor their prey are likely robust to limitless loss of their sea ice habitat.
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Affiliation(s)
- Karyn D Rode
- Alaska Science Center, U.S. Geological Survey, Anchorage, AK, USA
| | - Eric V Regehr
- Polar Science Center, University of Washington, Seattle, WA, USA
| | | | - Ryan R Wilson
- Marine Mammals Management, U.S. Fish and Wildlife Service, Anchorage, AK, USA
| | - Michelle St Martin
- Marine Mammals Management, U.S. Fish and Wildlife Service, Anchorage, AK, USA
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26
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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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27
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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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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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Penk SR, Bodner K, Vargas Soto JS, Chenery ES, Nascou A, Molnár PK. Mechanistic models can reveal infection pathways from prevalence data: the mysterious case of polar bears
Ursus maritimus
and
Trichinella nativa. OIKOS 2020. [DOI: 10.1111/oik.07458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stephanie R. Penk
- Laboratory of Quantitative Global Change Ecology, Dept of Biological Sciences, Univ. of Toronto Scarborough 1265 Military Trail Scarborough ON M1C 1A4 Canada
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto 25 Willcocks Street Toronto ON M5S 3B2 Canada
| | - Korryn Bodner
- Laboratory of Quantitative Global Change Ecology, Dept of Biological Sciences, Univ. of Toronto Scarborough 1265 Military Trail Scarborough ON M1C 1A4 Canada
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto 25 Willcocks Street Toronto ON M5S 3B2 Canada
| | - Juan S. Vargas Soto
- Laboratory of Quantitative Global Change Ecology, Dept of Biological Sciences, Univ. of Toronto Scarborough 1265 Military Trail Scarborough ON M1C 1A4 Canada
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto 25 Willcocks Street Toronto ON M5S 3B2 Canada
| | - Emily S. Chenery
- Laboratory of Quantitative Global Change Ecology, Dept of Biological Sciences, Univ. of Toronto Scarborough 1265 Military Trail Scarborough ON M1C 1A4 Canada
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto 25 Willcocks Street Toronto ON M5S 3B2 Canada
| | - Alexander Nascou
- Laboratory of Quantitative Global Change Ecology, Dept of Biological Sciences, Univ. of Toronto Scarborough 1265 Military Trail Scarborough ON M1C 1A4 Canada
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto 25 Willcocks Street Toronto ON M5S 3B2 Canada
| | - Péter K. Molnár
- Laboratory of Quantitative Global Change Ecology, Dept of Biological Sciences, Univ. of Toronto Scarborough 1265 Military Trail Scarborough ON M1C 1A4 Canada
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto 25 Willcocks Street Toronto ON M5S 3B2 Canada
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Boonstra R, Bodner K, Bosson C, Delehanty B, Richardson ES, Lunn NJ, Derocher AE, Molnár PK. The stress of Arctic warming on polar bears. GLOBAL CHANGE BIOLOGY 2020; 26:4197-4214. [PMID: 32364624 DOI: 10.1111/gcb.15142] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 04/15/2020] [Accepted: 04/23/2020] [Indexed: 05/25/2023]
Abstract
Arctic ecosystems are changing rapidly in response to climate warming. While Arctic mammals are highly evolved to these extreme environments, particularly with respect to their stress axis, some species may have limited capacity to adapt to this change. We examined changes in key components of the stress axis (cortisol and its carrier protein-corticosteroid binding globulin [CBG]) in polar bears (Ursus maritimus) from western Hudson Bay (N = 300) over a 33 year period (1983-2015) during which time the ice-free period was increasing. Changing sea ice phenology limits spring hunting opportunities and extends the period of onshore fasting. We assessed the response of polar bears to a standardized stressor (helicopter pursuit, darting, and immobilization) during their onshore fasting period (late summer-autumn) and quantified the serum levels of the maximum corticosteroid binding capacity (MCBC) of CBG, the serum protein that binds cortisol strongly, and free cortisol (FC). We quantified bear condition (age, sex, female with cubs or not, fat condition), sea ice (breakup in spring-summer, 1 year lagged freeze-up in autumn), and duration of fasting until sample collection as well as cumulative impacts of the latter environmental traits from the previous year. Data were separated into "good" years (1983-1990) when conditions were thought to be optimal and "poor" years (1991-2015) when sea ice conditions deteriorated and fasting on land was extended. MCBC explained 39.4% of the variation in the good years, but only 28.1% in the poor ones, using both biological and environmental variables. MCBC levels decreased with age. Changes in FC were complex, but more poorly explained. Counterintuitively, MCBC levels increased with increased time onshore, 1 year lag effects, and in poor ice years. We conclude that MCBC is a biomarker of stress in polar bears and that the changes we document are a consequence of climate warming.
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Affiliation(s)
- Rudy Boonstra
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Korryn Bodner
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Curtis Bosson
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Brendan Delehanty
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Evan S Richardson
- Wildlife Research Division, Science and Technology Branch, Environment and Climate Change Canada, Winnipeg, MB, Canada
| | - Nicholas J Lunn
- Environment and Climate Change Canada, Biological Sciences Building, University of Alberta, Edmonton, AB, Canada
| | - Andrew E Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Péter K Molnár
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
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32
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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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33
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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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34
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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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35
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Bourque J, Atwood TC, Divoky GJ, Stewart C, McKinney MA. Fatty acid-based diet estimates suggest ringed seal remain the main prey of southern Beaufort Sea polar bears despite recent use of onshore food resources. Ecol Evol 2020; 10:2093-2103. [PMID: 32128141 PMCID: PMC7042688 DOI: 10.1002/ece3.6043] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 12/20/2019] [Accepted: 01/03/2020] [Indexed: 01/20/2023] Open
Abstract
Polar bears (Ursus maritimus) from the southern Beaufort Sea (SB) subpopulation have traditionally fed predominantly upon ice-seals; however, as the proportion of the subpopulation using onshore habitat has recently increased, foraging on land-based resources, including remains of subsistence-harvested bowhead whales (Balaena mysticetus) and colonial nesting seabirds has been observed. Adipose tissue samples were collected from this subpopulation during the springs of 2013-2016 and analyzed for fatty acid signatures. Diet estimates were generated for the proportional consumption of ringed seal (Pusa hispida), bearded seal (Erignathus barbatus), and beluga whale (Delphinapterus leucas), relative to onshore foods, including bowhead whale remains and seabird, as represented by black guillemot (Cepphus grylle mandtii) nestlings and eggs. Quantitative fatty acid signature analysis (QFASA) estimated that the ice-obligate prey, ringed seal, remained the predominant prey species of SB polar bears (46.4 ± 1.8%), with much lower consumption of bearded seal (19.6 ± 2.0%), seabird (17.0 ± 1.2%), bowhead whale (15.0 ± 1.4%), and hardly any beluga whale (2.0 ± 0.5%). Adult and subadult females appeared to depend more on the traditional ringed seal prey than adult and subadult males. Diet estimates of SB polar bears showed significant interannual variability for all prey (F 12, 456 = 3.17, p < .001). Longer-term estimates suggested that both types of onshore prey, bowhead whale remains and seabird, have represented a moderate proportion of the food resources used by SB polar bears since at least the start of the 21st Century.
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Affiliation(s)
- Jennifer Bourque
- Wildlife and Fisheries Conservation CenterDepartment of Natural Resources and the Environment and Center for Environmental Sciences and EngineeringUniversity of ConnecticutStorrsCTUSA
| | - Todd C. Atwood
- Alaska Science CenterUnited States Geological SurveyAnchorageAKUSA
| | | | - Connie Stewart
- Department of Mathematics and StatisticsUniversity of New BrunswickSaint JohnNBCanada
| | - Melissa A. McKinney
- Wildlife and Fisheries Conservation CenterDepartment of Natural Resources and the Environment and Center for Environmental Sciences and EngineeringUniversity of ConnecticutStorrsCTUSA
- Department of Natural Resource SciencesMcGill UniversitySte‐Anne‐de‐BellevueQCCanada
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36
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Bampoh D, Earl JE, Zollner PA. Examining the relative influence of animal movement patterns and mortality models on the distribution of animal transported subsidies. Ecol Modell 2019. [DOI: 10.1016/j.ecolmodel.2019.108824] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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37
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Reimer JR, Mangel M, Derocher AE, Lewis MA. Modeling optimal responses and fitness consequences in a changing Arctic. GLOBAL CHANGE BIOLOGY 2019; 25:3450-3461. [PMID: 31077520 DOI: 10.1111/gcb.14681] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
Animals must balance a series of costs and benefits while trying to maximize their fitness. For example, an individual may need to choose how much energy to allocate to reproduction versus growth, or how much time to spend on vigilance versus foraging. Their decisions depend on complex interactions between environmental conditions, behavioral plasticity, reproductive biology, and energetic demands. As animals respond to novel environmental conditions caused by climate change, the optimal decisions may shift. Stochastic dynamic programming provides a flexible modeling framework with which to explore these trade-offs, but this method has not yet been used to study possible changes in optimal trade-offs caused by climate change. We created a stochastic dynamic programming model capturing trade-off decisions required by an individual adult female polar bear (Ursus maritimus) as well as the fitness consequences of her decisions. We predicted optimal foraging decisions throughout her lifetime as well as the energetic thresholds below which it is optimal for her to abandon a reproductive attempt. To explore the effects of climate change, we shortened the spring feeding period by up to 3 weeks, which led to predictions of riskier foraging behavior and higher reproductive thresholds. The resulting changes in fitness may be interpreted as a best-case scenario, where bears adapt instantaneously and optimally to new environmental conditions. If the spring feeding period was reduced by 1 week, her expected fitness declined by 15%, and if reduced by 3 weeks, expected fitness declined by 68%. This demonstrates an effective way to explore a species' optimal response to a changing landscape of costs and benefits and highlights the fact that small annual effects can result in large cumulative changes in expected lifetime fitness.
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Affiliation(s)
- Jody R Reimer
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
- Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Marc Mangel
- Institute of Marine Sciences and Department of Applied Mathematics and Statistics, University of California, Santa Cruz, Santa Cruz, California
- Department of Biology, University of Bergen, Bergen, Norway
| | - Andrew E Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Mark A Lewis
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
- Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, Canada
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38
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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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39
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Space use patterns affect stable isotopes of polar bears (Ursus maritimus) in the Beaufort Sea. Polar Biol 2019. [DOI: 10.1007/s00300-019-02546-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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40
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Scharf HR, Hooten MB, Wilson RR, Durner GM, Atwood TC. Accounting for phenology in the analysis of animal movement. Biometrics 2019; 75:810-820. [PMID: 30859552 DOI: 10.1111/biom.13052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 02/26/2019] [Indexed: 11/29/2022]
Abstract
The analysis of animal tracking data provides important scientific understanding and discovery in ecology. Observations of animal trajectories using telemetry devices provide researchers with information about the way animals interact with their environment and each other. For many species, specific geographical features in the landscape can have a strong effect on behavior. Such features may correspond to a single point (eg, dens or kill sites), or to higher dimensional subspaces (eg, rivers or lakes). Features may be relatively static in time (eg, coastlines or home-range centers), or may be dynamic (eg, sea ice extent or areas of high-quality forage for herbivores). We introduce a novel model for animal movement that incorporates active selection for dynamic features in a landscape. Our approach is motivated by the study of polar bear (Ursus maritimus) movement. During the sea ice melt season, polar bears spend much of their time on sea ice above shallow, biologically productive water where they hunt seals. The changing distribution and characteristics of sea ice throughout the year mean that the location of valuable habitat is constantly shifting. We develop a model for the movement of polar bears that accounts for the effect of this important landscape feature. We introduce a two-stage procedure for approximate Bayesian inference that allows us to analyze over 300 000 observed locations of 186 polar bears from 2012 to 2016. We use our model to estimate a spatial boundary of interest to wildlife managers that separates two subpopulations of polar bears from the Beaufort and Chukchi seas.
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Affiliation(s)
- Henry R Scharf
- Department of Statistics, Colorado State University, Fort Collins, Colorado
| | - Mevin B Hooten
- Department of Statistics, Colorado State University, Fort Collins, Colorado.,Department of Fish, Wildlife, and Conservation Biology, Colorado Cooperative Fish and Wildlife Research Unit, U.S. Geological Survey, Fort Collins, Colorado
| | - Ryan R Wilson
- Marine Mammals Management, U.S. Fish and Wildlife Service, Anchorage, Alaska
| | - George M Durner
- Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska
| | - Todd C Atwood
- Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska
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Fry TL, Friedrichs KR, Atwood TC, Duncan C, Simac K, Goldberg T. Reference intervals for blood-based biochemical analytes of southern Beaufort Sea polar bears. CONSERVATION PHYSIOLOGY 2019; 7:coz040. [PMID: 31548889 PMCID: PMC6748785 DOI: 10.1093/conphys/coz040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/09/2019] [Accepted: 06/10/2019] [Indexed: 05/14/2023]
Abstract
Accurate reference intervals (RIs) for commonly measured blood-based analytes are essential for health monitoring programmes. Baseline values for a panel of analytes can be used to monitor physiologic and pathophysiologic processes such as organ function, electrolyte balance and protein catabolism. Our reference population includes 651 serum samples from polar bears (Ursus maritimus) from the southern Beaufort Sea (SB) subpopulation sampled in Alaska, USA, between 1983 and 2016. To establish RI for 13 biochemical analytes, we defined specific criteria for characterizing the reference population and relevant subgroups. To account for differences in seasonal life history characteristics, we determined separate RI for the spring and fall seasons, when prey availability and energetic requirements of bears differ. We established RI for five subgroups in spring based on sex, age class and denning status, and three subgroups in fall based on sex and age class in females only. Alkaline phosphatase activities were twice as high in subadult as in adult polar bears in spring (z males = 4.08, P males < 0.001, z females = 3.90, P females < 0.001) and did not differ between seasons. Denning females had significantly higher glucose concentrations than non-denning females (z = 4.94, P < 0.001), possibly reflecting differences in energy expenditure during lactation. A total of 10 of the 13 analytes differed significantly between seasons in either males or females; however, the physiologic importance of these differences may be minimal. Establishing these RIs allows for temporal monitoring of polar bear health in the SB and may prove useful for assessing and monitoring additional polar bear subpopulations in a changing Arctic environment.
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Affiliation(s)
- Tricia L Fry
- Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, USA
- Corresponding author: Hanson Laboratories, University of Wisconsin–Madison, 1656 Linden Drive, Madison, Wisconsin 53706, USA. Tel: 608-448-5181.
| | - Kristen R Friedrichs
- Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, USA
| | - Todd C Atwood
- Alaska Science Center, US Geological Survey, Anchorage, AK, USA
| | - Colleen Duncan
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Kristin Simac
- Alaska Science Center, US Geological Survey, Anchorage, AK, USA
| | - Tony Goldberg
- Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, USA
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Whiteman JP, Harlow HJ, Durner GM, Regehr EV, Amstrup SC, Ben-David M. Heightened Immune System Function in Polar Bears Using Terrestrial Habitats. Physiol Biochem Zool 2019; 92:1-11. [DOI: 10.1086/698996] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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SURVEY OF ARCTIC ALASKAN WILDLIFE FOR INFLUENZA A ANTIBODIES: LIMITED EVIDENCE FOR EXPOSURE OF MAMMALS. J Wildl Dis 2018; 55:387-398. [PMID: 30289331 DOI: 10.7589/2018-05-128] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Influenza A viruses (IAVs) are maintained in wild waterbirds and have the potential to infect a broad range of species, including wild mammals. The Arctic Coastal Plain of Alaska supports a diverse suite of species, including waterfowl that are common hosts of IAVs. Mammals co-occur with geese and other migratory waterbirds during the summer breeding season, providing a plausible mechanism for interclass transmission of IAVs. To estimate IAV seroprevalence and identify the subtypes to which geese, loons, Arctic foxes ( Vulpes lagopus), caribou ( Rangifer tarandus), and polar bears ( Ursus maritimus) are potentially exposed, we used a blocking enzyme-linked immunosorbent assay (bELISA) and a hemagglutination inhibition (HI) assay to screen for antibodies to IAVs in samples collected during spring and summer of 2012-16. Apparent IAV seroprevalence using the bELISA was 50.3% in geese (range by species: 46-52.8%), 9% in loons (range by species: 3-20%), and 0.4% in Arctic foxes. We found no evidence for exposure to IAVs in polar bears or caribou by either assay. Among geese, we estimated detection probability from replicate bELISA analyses to be 0.92 and also found good concordance (>85%) between results from bELISA and HI assays, which identified antibodies reactive to H1, H6, and H9 subtype IAVs. In contrast, the HI assay detected antibodies in only one of seven loon samples that were positive by bELISA; that sample had low titers to both H4 and H5 IAV subtypes. Our results provide evidence that a relatively high proportion of waterbirds breeding on the Arctic Coastal Plain are exposed to IAVs, although it is unknown whether such exposure occurs locally or on staging or wintering grounds. In contrast, seroprevalence of IAVs in concomitant Arctic mammals is apparently low.
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Lillie KM, Gese EM, Atwood TC, Sonsthagen SA. Development of on-shore behavior among polar bears ( Ursus maritimus) in the southern Beaufort Sea: inherited or learned? Ecol Evol 2018; 8:7790-7799. [PMID: 30250663 PMCID: PMC6144971 DOI: 10.1002/ece3.4233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/16/2018] [Accepted: 04/20/2018] [Indexed: 11/24/2022] Open
Abstract
Polar bears (Ursus maritimus) are experiencing rapid and substantial changes to their environment due to global climate change. Polar bears of the southern Beaufort Sea (SB) have historically spent most of the year on the sea ice. However, recent reports from Alaska indicate that the proportion of the SB subpopulation observed on-shore during late summer and early fall has increased. Our objective was to investigate whether this on-shore behavior has developed through genetic inheritance, asocial learning, or through social learning. From 2010 to 2013, genetic data were collected from SB polar bears in the fall via hair snags and remote biopsy darting on-shore and in the spring from captures and remote biopsy darting on the sea ice. Bears were categorized as either on-shore or off-shore individuals based on their presence on-shore during the fall. Levels of genetic relatedness, first-order relatives, mother-offspring pairs, and father-offspring pairs were determined and compared within and between the two categories: on-shore versus off-shore. Results suggested transmission of on-shore behavior through either genetic inheritance or social learning as there was a higher than expected number of first-order relatives exhibiting on-shore behavior. Genetic relatedness and parentage data analyses were in concurrence with this finding, but further revealed mother-offspring social learning as the primary mechanism responsible for the development of on-shore behavior. Recognizing that on-shore behavior among polar bears was predominantly transmitted via social learning from mothers to their offspring has implications for future management and conservation as sea ice continues to decline.
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Affiliation(s)
- Kate M. Lillie
- Department of Wildland ResourcesUtah State UniversityLoganUtah
| | - Eric M. Gese
- U.S. Department of AgricultureWildlife ServicesNational Wildlife Research CenterDepartment of Wildland ResourcesUtah State UniversityLoganUtah
| | - Todd C. Atwood
- Alaska Science CenterU.S. Geological SurveyAnchorageAlaska
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Tartu S, Aars J, Andersen M, Polder A, Bourgeon S, Merkel B, Lowther AD, Bytingsvik J, Welker JM, Derocher AE, Jenssen BM, Routti H. Choose Your Poison-Space-Use Strategy Influences Pollutant Exposure in Barents Sea Polar Bears. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3211-3221. [PMID: 29363970 DOI: 10.1021/acs.est.7b06137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Variation in space-use is common within mammal populations. In polar bears, Ursus maritimus, some individuals follow the sea ice (offshore bears) whereas others remain nearshore yearlong (coastal bears). We studied pollutant exposure in relation to space-use patterns (offshore vs coastal) in adult female polar bears from the Barents Sea equipped with satellite collars (2000-2014, n = 152). First, we examined the differences in home range (HR) size and position, body condition, and diet proxies (nitrogen and carbon stable isotopes, n = 116) between offshore and coastal space-use. Second, we investigated how HR, space-use, body condition, and diet were related to plasma concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) ( n = 113), perfluoroalkyl substances (PFASs; n = 92), and hydroxylated-PCBs ( n = 109). Offshore females were in better condition and had a more specialized diet than did coastal females. PCBs, OCPs, and hydroxylated-PCB concentrations were not related to space-use strategy, yet PCB concentrations increased with increasing latitude, and hydroxylated-PCB concentrations were positively related to HR size. PFAS concentrations were 30-35% higher in offshore bears compared to coastal bears and also increased eastward. On the basis of the results we conclude that space-use of Barents Sea female polar bears influences their pollutant exposure, in particular plasma concentrations of PFAS.
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Affiliation(s)
- Sabrina Tartu
- Norwegian Polar Institute , Fram Centre , Tromsø NO-9296 , Norway
| | - Jon Aars
- Norwegian Polar Institute , Fram Centre , Tromsø NO-9296 , Norway
| | - Magnus Andersen
- Norwegian Polar Institute , Fram Centre , Tromsø NO-9296 , Norway
| | - Anuschka Polder
- Norwegian University of Life Science , Campus Adamstua , Oslo NO-1432 , Norway
| | - Sophie Bourgeon
- UiT-The Arctic University of Norway , Department of Arctic and Marine Biology , Tromsø NO-9010 , Norway
| | - Benjamin Merkel
- Norwegian Polar Institute , Fram Centre , Tromsø NO-9296 , Norway
| | - Andrew D Lowther
- Norwegian Polar Institute , Fram Centre , Tromsø NO-9296 , Norway
| | | | - Jeffrey M Welker
- Department of Biological Sciences , University of Alaska-Anchorage , Anchorage , Alaska 99508 , United States
- Department of Arctic Technology , University Center in Svalbard , Longyearbyen, Svalbard NO-9171 , Norway
| | - Andrew E Derocher
- Department of Biological Sciences , University of Alberta , Edmonton T6G 2R3 , Canada
| | - Bjørn Munro Jenssen
- Department of Arctic Technology , University Center in Svalbard , Longyearbyen, Svalbard NO-9171 , Norway
- Department of Biology , Norwegian University of Science and Technology , Trondheim NO-7491 , Norway
| | - Heli Routti
- Norwegian Polar Institute , Fram Centre , Tromsø NO-9296 , Norway
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Rode KD, Olson J, Eggett D, Douglas DC, Durner GM, Atwood TC, Regehr EV, Wilson RR, Smith T, St. Martin M. Den phenology and reproductive success of polar bears in a changing climate. J Mammal 2018. [DOI: 10.1093/jmammal/gyx181] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Karyn D Rode
- U.S. Geological Survey, Alaska Science Center, Anchorage, AK, USA
| | - Jay Olson
- Brigham Young University, Plant and Wildlife Sciences, Provo, UT, USA
| | - Dennis Eggett
- Center for Collaborative Research and Statistical Consulting, Department of Statistics, Brigham Young University, Provo, UT, USA
| | - David C Douglas
- U.S. Geological Survey, Alaska Science Center, Juneau, AK, USA
| | - George M Durner
- U.S. Geological Survey, Alaska Science Center, Anchorage, AK, USA
| | - Todd C Atwood
- U.S. Geological Survey, Alaska Science Center, Anchorage, AK, USA
| | - Eric V Regehr
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK, USA
| | - Ryan R Wilson
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK, USA
| | - Tom Smith
- Brigham Young University, Plant and Wildlife Sciences, Provo, UT, USA
| | - Michelle St. Martin
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK, USA
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Whiteman JP, Harlow HJ, Durner GM, Regehr EV, Amstrup SC, Ben-David M. Phenotypic plasticity and climate change: can polar bears respond to longer Arctic summers with an adaptive fast? Oecologia 2017; 186:369-381. [DOI: 10.1007/s00442-017-4023-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 11/22/2017] [Indexed: 02/02/2023]
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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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50
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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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