1
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Ross TR, Thiemann GW, Kirschhoffer BJ, Kirschhoffer J, York G, Derocher AE, Johnson AC, Lunn NJ, McGeachy D, Trim V, Northrup JM. Telemetry without collars: performance of fur- and ear-mounted satellite tags for evaluating the movement and behaviour of polar bears. ANIMAL BIOTELEMETRY 2024; 12:18. [PMID: 39022453 PMCID: PMC11249465 DOI: 10.1186/s40317-024-00373-2] [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: 01/09/2024] [Accepted: 05/29/2024] [Indexed: 07/20/2024]
Abstract
The study of animal movement provides insights into underlying ecological processes and informs analyses of behaviour and resource use, which have implications for species management and conservation. The tools used to study animal movement have evolved over the past decades, allowing for data collection from a variety of species, including those living in remote environments. Satellite-linked radio and GPS collars have been used to study polar bear (Ursus maritimus) ecology and movements throughout the circumpolar Arctic for over 50 years. However, due to morphology and growth constraints, only adult female polar bears can be reliably collared. Collars have proven to be safe, but there has been opposition to their use, resulting in a deficiency in data across much of the species' range. To bolster knowledge of movement characteristics and behaviours for polar bears other than adult females, while also providing an alternative to collars, we tested the use of fur- and ear-mounted telemetry tags that can be affixed to polar bears of any sex and age. We tested three fur tag designs (SeaTrkr, tribrush and pentagon tags), which we affixed to 15 adult and 1 subadult male polar bears along the coast of Hudson Bay during August-September 2021-2022. Fur tags were compared with ear tags deployed on 42 subadult and adult male polar bears captured on the coast or the sea ice between 2016 and 2022. We used data from the tags to quantify the amount of time subadult and adult males spent resting versus traveling while on land. Our results show the three fur tag designs remained functional for shorter mean durations (SeaTrkr = 58 days; tribrush = 47 days; pentagon = 22 days) than ear tags (121 days), but positional error estimates were comparable among the Argos-equipped tags. The GPS/Iridium-equipped SeaTrkr fur tags provided higher resolution and more frequent location data. Combined, the tags provided sufficient data to model different behavioural states. Furthermore, as hypothesized, subadult and adult male polar bears spent the majority of their time resting while on land, increasing time spent traveling as temperatures cooled. Fur tags show promise as a short-term means of collecting movement data from free-ranging polar bears. Supplementary Information The online version contains supplementary material available at 10.1186/s40317-024-00373-2.
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Affiliation(s)
- Tyler R. Ross
- Department of Biology, York University, Toronto, ON Canada
| | - Gregory W. Thiemann
- Faculty of Environmental and Urban Change, York University, Toronto, ON Canada
| | | | | | - Geoff York
- Polar Bears International, Bozeman, MT USA
| | - Andrew E. Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, AB Canada
| | - Amy C. Johnson
- Department of Biological Sciences, University of Alberta, Edmonton, AB Canada
- Ecofish Research Ltd., Courtenay, BC Canada
| | | | - David McGeachy
- Environment and Climate Change Canada, Edmonton, AB Canada
| | - Vicki Trim
- Department of Agriculture and Resource Development, Manitoba Sustainable Development, Thompson, MB Canada
| | - Joseph M. Northrup
- Ontario Ministry of Natural Resources and Forestry, Peterborough, ON Canada
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2
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Westbury MV, Brown SC, Lorenzen J, O’Neill S, Scott MB, McCuaig J, Cheung C, Armstrong E, Valdes PJ, Samaniego Castruita JA, Cabrera AA, Blom SK, Dietz R, Sonne C, Louis M, Galatius A, Fordham DA, Ribeiro S, Szpak P, Lorenzen ED. Impact of Holocene environmental change on the evolutionary ecology of an Arctic top predator. SCIENCE ADVANCES 2023; 9:eadf3326. [PMID: 37939193 PMCID: PMC10631739 DOI: 10.1126/sciadv.adf3326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 06/09/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
The Arctic is among the most climatically sensitive environments on Earth, and the disappearance of multiyear sea ice in the Arctic Ocean is predicted within decades. As apex predators, polar bears are sentinel species for addressing the impact of environmental variability on Arctic marine ecosystems. By integrating genomics, isotopic analysis, morphometrics, and ecological modeling, we investigate how Holocene environmental changes affected polar bears around Greenland. We uncover reductions in effective population size coinciding with increases in annual mean sea surface temperature, reduction in sea ice cover, declines in suitable habitat, and shifts in suitable habitat northward. Furthermore, we show that west and east Greenlandic polar bears are morphologically, and ecologically distinct, putatively driven by regional biotic and genetic differences. Together, we provide insights into the vulnerability of polar bears to environmental change and how the Arctic marine ecosystem plays a vital role in shaping the evolutionary and ecological trajectories of its inhabitants.
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Affiliation(s)
- Michael V. Westbury
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stuart C. Brown
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Department for Environment and Water, Adelaide, South Australia, Australia
| | - Julie Lorenzen
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stuart O’Neill
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Michael B. Scott
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Julia McCuaig
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Christina Cheung
- Department of Anthropology, Chinese University of Hong Kong, Shatin, Hong Kong
| | - Edward Armstrong
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
| | - Paul J. Valdes
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | | | - Andrea A. Cabrera
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stine Keibel Blom
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Rune Dietz
- Arctic Research Centre (ARC), Department of Ecoscience, Aarhus University, Frederiksborgvej 399, PO Box 358, Roskilde DK-4000, Denmark
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Christian Sonne
- Arctic Research Centre (ARC), Department of Ecoscience, Aarhus University, Frederiksborgvej 399, PO Box 358, Roskilde DK-4000, Denmark
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Marie Louis
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Greenland Institute of Natural Resources, Kivioq 2, PO Box 570, Nuuk 3900, Denmark
| | - Anders Galatius
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Damien A. Fordham
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Sofia Ribeiro
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Glaciology and Climate Department, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, Copenhagen DK-1350, Denmark
| | - Paul Szpak
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Eline D. Lorenzen
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
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3
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Silber KM, Mohankumar NM, Hefley TJ, Boyle WA. Emigration and survival correlate with different precipitation metrics throughout a grassland songbird's annual cycle. J Wildl Manage 2023. [DOI: 10.1002/jwmg.22371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- Katy M. Silber
- Kansas State University, Division of Biology Manhattan KS 66506 USA
| | | | - Trevor J. Hefley
- Kansas State University, Department of Statistics Manhattan KS 66506 USA
| | - W. Alice Boyle
- Kansas State University, Division of Biology Manhattan KS 66506 USA
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4
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Togunov RR, Derocher AE, Lunn NJ, Auger-Méthé M. Drivers of polar bear behavior and the possible effects of prey availability on foraging strategy. MOVEMENT ECOLOGY 2022; 10:50. [PMID: 36384775 PMCID: PMC9670556 DOI: 10.1186/s40462-022-00351-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 11/09/2022] [Indexed: 06/05/2023]
Abstract
BACKGROUND Change in behavior is one of the earliest responses to variation in habitat suitability. It is therefore important to understand the conditions that promote different behaviors, particularly in areas undergoing environmental change. Animal movement is tightly linked to behavior and remote tracking can be used to study ethology when direct observation is not possible. METHODS We used movement data from 14 polar bears (Ursus maritimus) in Hudson Bay, Canada, during the foraging season (January-June), when bears inhabit the sea ice. We developed an error-tolerant method to correct for sea ice drift in tracking data. Next, we used hidden Markov models with movement and orientation relative to wind to study three behaviors (stationary, area-restricted search, and olfactory search) and examine effects of 11 covariates on behavior. RESULTS Polar bears spent approximately 47% of their time in the stationary drift state, 29% in olfactory search, and 24% in area-restricted search. High energy behaviors occurred later in the day (around 20:00) compared to other populations. Second, olfactory search increased as the season progressed, which may reflect a shift in foraging strategy from still-hunting to active search linked to a shift in seal availability (i.e., increase in haul-outs from winter to the spring pupping and molting seasons). Last, we found spatial patterns of distribution linked to season, ice concentration, and bear age that may be tied to habitat quality and competitive exclusion. CONCLUSIONS Our observations were generally consistent with predictions of the marginal value theorem, and differences between our findings and other populations could be explained by regional or temporal variation in resource availability. Our novel movement analyses and finding can help identify periods, regions, and conditions of critical habitat.
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Affiliation(s)
- Ron R. Togunov
- Institute for the Oceans and Fisheries, The University of British Columbia, V6T 1Z4 Vancouver, Canada
- Department of Zoology, The University of British Columbia, Vancouver, V6T 1Z4 Canada
| | - Andrew E. Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, T6G 2E9 Canada
| | - Nicholas J. Lunn
- Wildlife Research Division, Science and Technology Branch, Environment and Climate Change Canada, Edmonton, T6G 2E9 Canada
| | - Marie Auger-Méthé
- Institute for the Oceans and Fisheries, The University of British Columbia, V6T 1Z4 Vancouver, Canada
- Department of Statistics, The University of British Columbia, Vancouver, V6T 1Z4 Canada
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5
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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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6
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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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7
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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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8
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Jagielski PM, Dey CJ, Gilchrist HG, Richardson ES, Semeniuk CA. Polar bear foraging on common eider eggs: estimating the energetic consequences of a climate-mediated behavioural shift. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2020.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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9
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Johnson AC, Reimer JR, Lunn NJ, Stirling I, McGeachy D, Derocher AE. Influence of sea ice dynamics on population energetics of Western Hudson Bay polar bears. CONSERVATION PHYSIOLOGY 2020; 8:coaa132. [PMID: 33408870 PMCID: PMC7772618 DOI: 10.1093/conphys/coaa132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/23/2020] [Accepted: 12/07/2020] [Indexed: 05/27/2023]
Abstract
The Arctic marine ecosystem has experienced extensive changes in sea ice dynamics, with significant effects on ice-dependent species such as polar bears (Ursus maritimus). We used annual estimates of the numbers of bears onshore in the core summering area, age/sex structure and body condition data to estimate population energy density and storage energy in Western Hudson Bay polar bears from 1985 to 2018. We examined intra-population variation in energetic patterns, temporal energetic trends and the relationship between population energetics and sea ice conditions. Energy metrics for most demographic classes declined over time in relation to earlier sea ice breakup, most significantly for solitary adult females and subadult males, suggesting their greater vulnerability to nutritional stress than other age/sex classes. Temporal declines in population energy metrics were related to earlier breakup and longer lagged open-water periods, suggesting multi-year effects of sea ice decline. The length of the open-water period ranged from 102 to 166 days and increased significantly by 9.9 days/decade over the study period. Total population energy density and storage energy were significantly lower when sea ice breakup occurred earlier and the lagged open-water period was longer. At the earliest breakup and a lagged open-water period of 180 days, population energy density was predicted to be 33% lower than our minimum estimated energy density and population storage energy was predicted to be 40% lower than the minimum estimated storage energy. Consequently, over the study, the total population energy density declined by 53% (mean: 3668 ± 386 MJ kg-1/decade) and total population storage energy declined by 56% (mean: 435900 ± 46770 MJ/decade). This study provides insights into ecological mechanisms linking population responses to sea ice decline and highlights the significance of maintaining long-term research programs.
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Affiliation(s)
- Amy C Johnson
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Jody R Reimer
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
- Department of Mathematics, University of Utah, Salt Lake City, UT 84112, USA
| | - Nicholas J Lunn
- Environment and Climate Change Canada, CW-422 Biological Sciences Building, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Ian Stirling
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
- Environment and Climate Change Canada, CW-422 Biological Sciences Building, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - David McGeachy
- Environment and Climate Change Canada, CW-422 Biological Sciences Building, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Andrew E Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
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10
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Kotze R, Marshal JP, Winterbach CW, Winterbach HE, Keith M. Demographic consequences of habitat loss and crowding in large carnivores: A natural experiment. Afr J Ecol 2020. [DOI: 10.1111/aje.12786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robynne Kotze
- Centre for African Ecology School of Animal, Plant and Environmental Sciences University of the Witwatersrand Johannesburg South Africa
| | - Jason P. Marshal
- Centre for African Ecology School of Animal, Plant and Environmental Sciences University of the Witwatersrand Johannesburg South Africa
| | - Christiaan W. Winterbach
- Eugène Marais Research Chair for Wildlife Management Mammal Research Institute University of Pretoria Pretoria South Africa
- Tau Consultants (Pty) Ltd Maun Botswana
| | - Hanlie E.K. Winterbach
- Eugène Marais Research Chair for Wildlife Management Mammal Research Institute University of Pretoria Pretoria South Africa
- Tau Consultants (Pty) Ltd Maun Botswana
| | - Mark Keith
- Eugène Marais Research Chair for Wildlife Management Mammal Research Institute University of Pretoria Pretoria South Africa
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11
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Biddlecombe BA, Bayne EM, Lunn NJ, McGeachy D, Derocher AE. Comparing sea ice habitat fragmentation metrics using integrated step selection analysis. Ecol Evol 2020; 10:4791-4800. [PMID: 32551061 PMCID: PMC7297736 DOI: 10.1002/ece3.6233] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 02/21/2020] [Accepted: 03/10/2020] [Indexed: 11/06/2022] Open
Abstract
Habitat fragmentation occurs when continuous habitat gets broken up as a result of ecosystem change. While commonly studied in terrestrial ecosystems, Arctic sea ice ecosystems also experience fragmentation, but are rarely studied in this context. Most fragmentation analyses are conducted using patch-based metrics, which are potentially less suitable for sea ice that has gradual changes between sea ice cover, than distinct "long-term" patches. Using an integrated step selection analysis, we compared the descriptive power of a patch-based metric to a more novel metric, the variation in local spatial autocorrelation over time. We used satellite telemetry data from 39 adult female polar bears (Ursus maritimus) in Hudson Bay to examine their sea ice habitat using Advanced Microwave Scanning Radiometer 2 data during sea ice breakup in May through July from 2013-2018. Spatial autocorrelation resulted in better model fits across 64% of individuals, although both metrics were more effective in describing movement patterns than habitat selection. Variation in local spatial autocorrelation allows for the visualization of sea ice habitat at complex spatial and temporal scales, condensing a targeted time period of habitat that would otherwise have to be analyzed daily.
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Affiliation(s)
| | - Erin M. Bayne
- Department of Biological SciencesUniversity of AlbertaEdmontonAlbertaCanada
| | - Nicholas J. Lunn
- Wildlife Research Division, Science and Technology BranchEnvironment and Climate Change CanadaEdmontonABCanada
| | - David McGeachy
- Wildlife Research Division, Science and Technology BranchEnvironment and Climate Change CanadaEdmontonABCanada
| | - Andrew E. Derocher
- Department of Biological SciencesUniversity of AlbertaEdmontonAlbertaCanada
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12
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Jenkins DA, Yannic G, Schaefer JA, Conolly J, Lecomte N. Population structure of caribou in an ice-bound archipelago. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12748] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Deborah. A. Jenkins
- Environmental and Life Sciences Graduate Program; Trent University; Peterborough ON Canada
- Canada Research Chair in Polar and Boreal Ecology and Centre d'Études Nordiques; University of Moncton; Moncton NB Canada
| | - Glenn Yannic
- University of Grenoble Alpes; University of Savoie Mont Blanc; CNRS; LECA (Laboratoire d'Ecologie Alpine); Le Bourget-du-Lac France
| | | | - James Conolly
- Department of Anthropology; Trent University; Peterborough ON Canada
| | - Nicolas Lecomte
- Canada Research Chair in Polar and Boreal Ecology and Centre d'Études Nordiques; University of Moncton; Moncton NB Canada
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13
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Laidre KL, Born EW, Atkinson SN, Wiig Ø, Andersen LW, Lunn NJ, Dyck M, Regehr EV, McGovern R, Heagerty P. Range contraction and increasing isolation of a polar bear subpopulation in an era of sea-ice loss. Ecol Evol 2018; 8:2062-2075. [PMID: 29468025 PMCID: PMC5817132 DOI: 10.1002/ece3.3809] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 11/26/2017] [Indexed: 11/10/2022] Open
Abstract
Climate change is expected to result in range shifts and habitat fragmentation for many species. In the Arctic, loss of sea ice will reduce barriers to dispersal or eliminate movement corridors, resulting in increased connectivity or geographic isolation with sweeping implications for conservation. We used satellite telemetry, data from individually marked animals (research and harvest), and microsatellite genetic data to examine changes in geographic range, emigration, and interpopulation connectivity of the Baffin Bay (BB) polar bear (Ursus maritimus) subpopulation over a 25-year period of sea-ice loss. Satellite telemetry collected from n = 43 (1991-1995) and 38 (2009-2015) adult females revealed a significant contraction in subpopulation range size (95% bivariate normal kernel range) in most months and seasons, with the most marked reduction being a 70% decline in summer from 716,000 km2 (SE 58,000) to 211,000 km2 (SE 23,000) (p < .001). Between the 1990s and 2000s, there was a significant shift northward during the on-ice seasons (2.6° shift in winter median latitude, 1.1° shift in spring median latitude) and a significant range contraction in the ice-free summers. Bears in the 2000s were less likely to leave BB, with significant reductions in the numbers of bears moving into Davis Strait (DS) in winter and Lancaster Sound (LS) in summer. Harvest recoveries suggested both short and long-term fidelity to BB remained high over both periods (83-99% of marked bears remained in BB). Genetic analyses using eight polymorphic microsatellites confirmed a previously documented differentiation between BB, DS, and LS; yet weakly differentiated BB from Kane Basin (KB) for the first time. Our results provide the first multiple lines of evidence for an increasingly geographically and functionally isolated subpopulation of polar bears in the context of long-term sea-ice loss. This may be indicative of future patterns for other polar bear subpopulations under climate change.
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Affiliation(s)
- Kristin L. Laidre
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWAUSA
- Greenland Institute of Natural ResourcesNuukGreenland
| | - Erik W. Born
- Greenland Institute of Natural ResourcesNuukGreenland
| | - Stephen N. Atkinson
- Wildlife Research SectionDepartment of EnvironmentGovernment of NunavutIgloolikNUCanada
| | - Øystein Wiig
- Natural History MuseumUniversity of OsloOsloNorway
| | | | - Nicholas J. Lunn
- Environment and Climate Change CanadaUniversity of AlbertaEdmontonABCanada
| | - Markus Dyck
- Wildlife Research SectionDepartment of EnvironmentGovernment of NunavutIgloolikNUCanada
| | - Eric V. Regehr
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWAUSA
| | - Richard McGovern
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWAUSA
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14
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Pagano AM, Durner GM, Rode KD, Atwood TC, Atkinson SN, Peacock E, Costa DP, Owen MA, Williams TM. High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear. Science 2018; 359:568-572. [DOI: 10.1126/science.aan8677] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 12/19/2017] [Indexed: 11/02/2022]
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15
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Jenkins DA, Lecomte N, Schaefer JA, Olsen SM, Swingedouw D, Côté SD, Pellissier L, Yannic G. Loss of connectivity among island-dwelling Peary caribou following sea ice decline. Biol Lett 2017; 12:rsbl.2016.0235. [PMID: 27651531 DOI: 10.1098/rsbl.2016.0235] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 08/25/2016] [Indexed: 11/12/2022] Open
Abstract
Global warming threatens to reduce population connectivity for terrestrial wildlife through significant and rapid changes to sea ice. Using genetic fingerprinting, we contrasted extant connectivity in island-dwelling Peary caribou in northern Canada with continental-migratory caribou. We next examined if sea-ice contractions in the last decades modulated population connectivity and explored the possible impact of future climate change on long-term connectivity among island caribou. We found a strong correlation between genetic and geodesic distances for both continental and Peary caribou, even after accounting for the possible effect of sea surface. Sea ice has thus been an effective corridor for Peary caribou, promoting inter-island connectivity and population mixing. Using a time series of remote sensing sea-ice data, we show that landscape resistance in the Canadian Arctic Archipelago has increased by approximately 15% since 1979 and may further increase by 20-77% by 2086 under a high-emission scenario (RCP8.5). Under the persistent increase in greenhouse gas concentrations, reduced connectivity may isolate island-dwelling caribou with potentially significant consequences for population viability.
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Affiliation(s)
- Deborah A Jenkins
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada K9 L 0G2 Canada Research Chair in Polar and Boreal Ecology and Centre d'Études Nordiques, Department of Biology, University of Moncton, Moncton, New Brunswick, Canada E1A 3E9
| | - Nicolas Lecomte
- Canada Research Chair in Polar and Boreal Ecology and Centre d'Études Nordiques, Department of Biology, University of Moncton, Moncton, New Brunswick, Canada E1A 3E9
| | - James A Schaefer
- Department of Biology, Trent University, Peterborough, Ontario, Canada K9 L 0G2
| | - Steffen M Olsen
- Danish Meteorological Institute, Lyngbyvej 100, 2100 Copenhagen, Denmark
| | - Didier Swingedouw
- UMR CNRS 5805 EPOC-OASU-Université de Bordeaux, Allée Georoy St Hilaire, 33615 Pessac, France
| | - Steeve D Côté
- Département de Biologie and Centre d'Études Nordiques, Université Laval, Québec, Canada G1V0A6
| | - Loïc Pellissier
- Landscape Ecology, Institute of Terrestrial Ecosystems, ETH Zürich, Zürich, Switzerland Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
| | - Glenn Yannic
- LECA - Laboratoire d'Écologie Alpine - UMR CNRS 5553, Université Savoie Mont Blanc, 73376 Le Bourget-du-Lac, France
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Durner GM, Douglas DC, Albeke SE, Whiteman JP, Amstrup SC, Richardson E, Wilson RR, Ben-David M. Increased Arctic sea ice drift alters adult female polar bear movements and energetics. GLOBAL CHANGE BIOLOGY 2017; 23:3460-3473. [PMID: 28586523 DOI: 10.1111/gcb.13746] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 03/17/2017] [Accepted: 04/13/2017] [Indexed: 06/07/2023]
Abstract
Recent reductions in thickness and extent have increased drift rates of Arctic sea ice. Increased ice drift could significantly affect the movements and the energy balance of polar bears (Ursus maritimus) which forage, nearly exclusively, on this substrate. We used radio-tracking and ice drift data to quantify the influence of increased drift on bear movements, and we modeled the consequences for energy demands of adult females in the Beaufort and Chukchi seas during two periods with different sea ice characteristics. Westward and northward drift of the sea ice used by polar bears in both regions increased between 1987-1998 and 1999-2013. To remain within their home ranges, polar bears responded to the higher westward ice drift with greater eastward movements, while their movements north in the spring and south in fall were frequently aided by ice motion. To compensate for more rapid westward ice drift in recent years, polar bears covered greater daily distances either by increasing their time spent active (7.6%-9.6%) or by increasing their travel speed (8.5%-8.9%). This increased their calculated annual energy expenditure by 1.8%-3.6% (depending on region and reproductive status), a cost that could be met by capturing an additional 1-3 seals/year. Polar bears selected similar habitats in both periods, indicating that faster drift did not alter habitat preferences. Compounding reduced foraging opportunities that result from habitat loss; changes in ice drift, and associated activity increases, likely exacerbate the physiological stress experienced by polar bears in a warming Arctic.
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Affiliation(s)
- George M Durner
- U.S. Geological Survey, Alaska Science Center, Anchorage, AK, USA
| | - David C Douglas
- U.S. Geological Survey, Alaska Science Center, Juneau, AK, USA
| | - Shannon E Albeke
- Wyoming Geographic Information Science Center, University of Wyoming, Laramie, WY, USA
| | - John P Whiteman
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | | | - Evan Richardson
- Environment and Climate Change Canada, University of Alberta, Edmonton, AB, Canada
| | - Ryan R Wilson
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK, USA
| | - Merav Ben-David
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
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17
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Apparent climate-mediated loss and fragmentation of core habitat of the American pika in the Northern Sierra Nevada, California, USA. PLoS One 2017; 12:e0181834. [PMID: 28854268 PMCID: PMC5576638 DOI: 10.1371/journal.pone.0181834] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 07/08/2017] [Indexed: 12/03/2022] Open
Abstract
Contemporary climate change has been widely documented as the apparent cause of range contraction at the edge of many species distributions but documentation of climate change as a cause of extirpation and fragmentation of the interior of a species’ core habitat has been lacking. Here, we report the extirpation of the American pika (Ochotona princeps), a temperature-sensitive small mammal, from a 165-km2 area located within its core habitat in California’s Sierra Nevada mountains. While sites surrounding the area still maintain pikas, radiocarbon analyses of pika fecal pellets recovered within this area indicate that former patch occupancy ranges from before 1955, the beginning of the atmospheric spike in radiocarbon associated with above ground atomic bomb testing, to c. 1991. Despite an abundance of suitable rocky habitat climate warming appears to have precipitated their demise. Weather station data reveal a 1.9°C rise in local temperature and a significant decline in snowpack over the period of record, 1910–2015, pushing pika habitat into increasingly tenuous climate conditions during the period of extirpation. This is among the first accounts of an apparently climate-mediated, modern extirpation of a species from an interior portion of its geographic distribution, resulting in habitat fragmentation, and is the largest area yet reported for a modern-era pika extirpation. Our finding provides empirical support to model projections, indicating that even core areas of species habitat are vulnerable to climate change within a timeframe of decades.
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18
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Pagano AM, Rode KD, Cutting A, Owen MA, Jensen S, Ware JV, Robbins CT, Durner GM, Atwood TC, Obbard ME, Middel KR, Thiemann GW, Williams TM. Using tri-axial accelerometers to identify wild polar bear behaviors. ENDANGER SPECIES RES 2017. [DOI: 10.3354/esr00779] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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19
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Galicia MP, Thiemann GW, Dyck MG, Ferguson SH, Higdon JW. Dietary habits of polar bears in Foxe Basin, Canada: possible evidence of a trophic regime shift mediated by a new top predator. Ecol Evol 2016; 6:6005-18. [PMID: 27547372 PMCID: PMC4983609 DOI: 10.1002/ece3.2173] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 04/05/2016] [Accepted: 04/13/2016] [Indexed: 11/09/2022] Open
Abstract
Polar bear (Ursus maritimus) subpopulations in several areas with seasonal sea ice regimes have shown declines in body condition, reproductive rates, or abundance as a result of declining sea ice habitat. In the Foxe Basin region of Nunavut, Canada, the size of the polar bear subpopulation has remained largely stable over the past 20 years, despite concurrent declines in sea ice habitat. We used fatty acid analysis to examine polar bear feeding habits in Foxe Basin and thus potentially identify ecological factors contributing to population stability. Adipose tissue samples were collected from 103 polar bears harvested during 2010-2012. Polar bear diet composition varied spatially within the region with ringed seal (Pusa hispida) comprising the primary prey in northern and southern Foxe Basin, whereas polar bears in Hudson Strait consumed equal proportions of ringed seal and harp seal (Pagophilus groenlandicus). Walrus (Odobenus rosmarus) consumption was highest in northern Foxe Basin, a trend driven by the ability of adult male bears to capture large-bodied prey. Importantly, bowhead whale (Balaena mysticetus) contributed to polar bear diets in all areas and all age and sex classes. Bowhead carcasses resulting from killer whale (Orcinus orca) predation and subsistence harvest potentially provide an important supplementary food source for polar bears during the ice-free period. Our results suggest that the increasing abundance of killer whales and bowhead whales in the region could be indirectly contributing to improved polar bear foraging success despite declining sea ice habitat. However, this indirect interaction between top predators may be temporary if continued sea ice declines eventually severely limit on-ice feeding opportunities for polar bears.
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Affiliation(s)
- Melissa P Galicia
- Department of Biology York University Toronto Ontario M3J 1P3 Canada
| | - Gregory W Thiemann
- Faculty of Environmental Studies York University Toronto Ontario M3J 1P3 Canada
| | - Markus G Dyck
- Wildlife Research Section Department of Environment Government of Nunavut P.O. Box 209 Igloolik Nunavut X0A 0L0 Canada
| | - Steven H Ferguson
- Fisheries and Oceans Canada 501 University Crescent Winnipeg Manitoba R3T 2N6 Canada
| | - Jeff W Higdon
- Higdon Wildlife Consulting 912 Ashburn Street Winnipeg Manitoba R3G 3C9 Canada
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20
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Atwood TC, Marcot BG, Douglas DC, Amstrup SC, Rode KD, Durner GM, Bromaghin JF. Forecasting the relative influence of environmental and anthropogenic stressors on polar bears. Ecosphere 2016. [DOI: 10.1002/ecs2.1370] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Todd C. Atwood
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
| | - Bruce G. Marcot
- Pacific Northwest Research StationU.S.D.A. Forest Service Portland Oregon 97208 USA
| | - David C. Douglas
- Alaska Science CenterU.S. Geological Survey Juneau Alaska 99801 USA
| | | | - Karyn D. Rode
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
| | - George M. Durner
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
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21
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Kutschera VE, Frosch C, Janke A, Skírnisson K, Bidon T, Lecomte N, Fain SR, Eiken HG, Hagen SB, Arnason U, Laidre KL, Nowak C, Hailer F. High genetic variability of vagrant polar bears illustrates importance of population connectivity in fragmented sea ice habitats. Anim Conserv 2016. [DOI: 10.1111/acv.12250] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- V. E. Kutschera
- Senckenberg Biodiversity and Climate Research Centre (BiK-F); Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main; Germany
- Department of Evolutionary Biology, Evolutionary Biology Centre; Uppsala University; Uppsala Sweden
| | - C. Frosch
- Conservation Genetics Group; Senckenberg Research Institute and Natural History Museum Frankfurt; Gelnhausen Germany
| | - A. Janke
- Senckenberg Biodiversity and Climate Research Centre (BiK-F); Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main; Germany
- Institute for Ecology, Evolution and Diversity; Goethe University Frankfurt, Frankfurt am Main; Germany
| | - K. Skírnisson
- Institute for Experimental Pathology; Keldur, University of Iceland; Reykjavík Iceland
| | - T. Bidon
- Senckenberg Biodiversity and Climate Research Centre (BiK-F); Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main; Germany
| | - N. Lecomte
- Canada Research Chair in Polar and Boreal Ecology, Department of Biology; University of Moncton; Moncton NB Canada
- Government of Nunavut; Igloolik NU Canada
| | - S. R. Fain
- National Fish and Wildlife Forensic Laboratory; Ashland OR USA
| | - H. G. Eiken
- NIBIO, Norwegian Institute for Bioeconomy Research; Svanvik Norway
| | - S. B. Hagen
- NIBIO, Norwegian Institute for Bioeconomy Research; Svanvik Norway
| | - U. Arnason
- Faculty of Medicine; University of Lund; Lund Sweden
| | - K. L. Laidre
- Applied Physics Laboratory; Polar Science Center, University of Washington; Seattle WA USA
| | - C. Nowak
- Conservation Genetics Group; Senckenberg Research Institute and Natural History Museum Frankfurt; Gelnhausen Germany
| | - F. Hailer
- Senckenberg Biodiversity and Climate Research Centre (BiK-F); Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main; Germany
- School of Biosciences; Cardiff University; Cardiff, Wales UK
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22
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Galicia MP, Thiemann GW, Dyck MG, Ferguson SH. Characterization of polar bear (Ursus maritimus) diets in the Canadian High Arctic. Polar Biol 2015. [DOI: 10.1007/s00300-015-1757-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Sahanatien V, Peacock E, Derocher AE. Population substructure and space use of Foxe Basin polar bears. Ecol Evol 2015; 5:2851-64. [PMID: 26306171 PMCID: PMC4541990 DOI: 10.1002/ece3.1571] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 05/11/2015] [Accepted: 05/18/2015] [Indexed: 11/19/2022] Open
Abstract
Climate change has been identified as a major driver of habitat change, particularly for sea ice-dependent species such as the polar bear (Ursus maritimus). Population structure and space use of polar bears have been challenging to quantify because of their circumpolar distribution and tendency to range over large areas. Knowledge of movement patterns, home range, and habitat is needed for conservation and management. This is the first study to examine the spatial ecology of polar bears in the Foxe Basin management unit of Nunavut, Canada. Foxe Basin is in the mid-Arctic, part of the seasonal sea ice ecoregion and it is being negatively affected by climate change. Our objectives were to examine intrapopulation spatial structure, to determine movement patterns, and to consider how polar bear movements may respond to changing sea ice habitat conditions. Hierarchical and fuzzy cluster analyses were used to assess intrapopulation spatial structure of geographic position system satellite-collared female polar bears. Seasonal and annual movement metrics (home range, movement rates, time on ice) and home-range fidelity (static and dynamic overlap) were compared to examine the influence of regional sea ice on movements. The polar bears were distributed in three spatial clusters, and there were differences in the movement metrics between clusters that may reflect sea ice habitat conditions. Within the clusters, bears moved independently of each other. Annual and seasonal home-range fidelity was observed, and the bears used two movement patterns: on-ice range residency and annual migration. We predict that home-range fidelity may decline as the spatial and temporal predictability of sea ice changes. These new findings also provide baseline information for managing and monitoring this polar bear population.
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Affiliation(s)
- Vicki Sahanatien
- Department of Biological Sciences, University of AlbertaEdmonton, Alberta, T6G 2E9, Canada
| | - Elizabeth Peacock
- Department of Environment, Government of NunavutIgloolik, Nunavut, X0A 0L0, Canada
| | - Andrew E Derocher
- Department of Biological Sciences, University of AlbertaEdmonton, Alberta, T6G 2E9, Canada
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24
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Peacock E, Sonsthagen SA, Obbard ME, Boltunov A, Regehr EV, Ovsyanikov N, Aars J, Atkinson SN, Sage GK, Hope AG, Zeyl E, Bachmann L, Ehrich D, Scribner KT, Amstrup SC, Belikov S, Born EW, Derocher AE, Stirling I, Taylor MK, Wiig Ø, Paetkau D, Talbot SL. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic. PLoS One 2015; 10:e112021. [PMID: 25562525 PMCID: PMC4285400 DOI: 10.1371/journal.pone.0112021] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 09/19/2014] [Indexed: 11/18/2022] Open
Abstract
We provide an expansive analysis of polar bear (Ursus maritimus) circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how genetic demography changed with ancient fluctuations in climate. Characterizing their circumpolar genetic structure using microsatellite data, we defined four clusters that largely correspond to current ecological and oceanographic factors: Eastern Polar Basin, Western Polar Basin, Canadian Archipelago and Southern Canada. We document evidence for recent (ca. last 1–3 generations) directional gene flow from Southern Canada and the Eastern Polar Basin towards the Canadian Archipelago, an area hypothesized to be a future refugium for polar bears as climate-induced habitat decline continues. Our data provide empirical evidence in support of this hypothesis. The direction of current gene flow differs from earlier patterns of gene flow in the Holocene. From analyses of mitochondrial DNA, the Canadian Archipelago cluster and the Barents Sea subpopulation within the Eastern Polar Basin cluster did not show signals of population expansion, suggesting these areas may have served also as past interglacial refugia. Mismatch analyses of mitochondrial DNA data from polar and the paraphyletic brown bear (U. arctos) uncovered offset signals in timing of population expansion between the two species, that are attributed to differential demographic responses to past climate cycling. Mitogenomic structure of polar bears was shallow and developed recently, in contrast to the multiple clades of brown bears. We found no genetic signatures of recent hybridization between the species in our large, circumpolar sample, suggesting that recently observed hybrids represent localized events. Documenting changes in subpopulation connectivity will allow polar nations to proactively adjust conservation actions to continuing decline in sea-ice habitat.
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Affiliation(s)
- Elizabeth Peacock
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
- Department of Environment, Government of Nunavut, Igloolik, Nunavut, Canada
- * E-mail:
| | - Sarah A. Sonsthagen
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
| | - Martyn E. Obbard
- Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario, Canada
| | - Andrei Boltunov
- All-Russian Research Institute for Nature Protection, Moscow, Russian Federation
| | - Eric V. Regehr
- US Fish and Wildlife Service, Marine Mammals Management, Anchorage, Alaska, United States of America
| | | | - Jon Aars
- Norwegian Polar Institute, Tromsø, Norway
| | | | - George K. Sage
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
| | - Andrew G. Hope
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
| | - Eve Zeyl
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Lutz Bachmann
- Natural History Museum, University of Oslo, Oslo, Norway
| | | | - Kim T. Scribner
- Department of Zoology, Michigan State University, East Lansing, Michigan, United States of America
| | - Steven C. Amstrup
- Polar Bears International, Bozeman, Montana, United States of America
| | - Stanislav Belikov
- All-Russian Research Institute for Nature Protection, Moscow, Russian Federation
| | - Erik W. Born
- Greenland Institute of Natural Resources, Copenhagen, Denmark
| | - Andrew E. Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Ian Stirling
- Science & Technology Branch, Environment Canada, Edmonton, Alberta, Canada
| | - Mitchell K. Taylor
- Faculty of Science and Environmental Studies, Lakehead University, Thunder Bay, Ontario, Canada
| | - Øystein Wiig
- Natural History Museum, University of Oslo, Oslo, Norway
| | - David Paetkau
- Wildlife Genetics International, Nelson, British Columbia, Canada
| | - Sandra L. Talbot
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
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25
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Owen MA, Swaisgood RR, Slocomb C, Amstrup SC, Durner GM, Simac K, Pessier AP. An experimental investigation of chemical communication in the polar bear. J Zool (1987) 2014. [DOI: 10.1111/jzo.12181] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. A. Owen
- Institute for Conservation Research; San Diego Zoo Global; San Diego CA USA
| | - R. R. Swaisgood
- Institute for Conservation Research; San Diego Zoo Global; San Diego CA USA
| | - C. Slocomb
- Institute for Conservation Research; San Diego Zoo Global; San Diego CA USA
| | | | - G. M. Durner
- Alaska Science Center; US Geological Survey; Anchorage AK USA
| | - K. Simac
- Alaska Science Center; US Geological Survey; Anchorage AK USA
| | - A. P. Pessier
- Institute for Conservation Research; San Diego Zoo Global; San Diego CA USA
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26
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Iacozza J, Ferguson SH. Spatio-temporal variability of snow over sea ice in western Hudson Bay, with reference to ringed seal pup survival. Polar Biol 2014. [DOI: 10.1007/s00300-014-1484-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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Iverson SA, Gilchrist HG, Smith PA, Gaston AJ, Forbes MR. Longer ice-free seasons increase the risk of nest depredation by polar bears for colonial breeding birds in the Canadian Arctic. Proc Biol Sci 2014; 281:20133128. [PMID: 24500172 PMCID: PMC3924086 DOI: 10.1098/rspb.2013.3128] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Northern polar regions have warmed more than other parts of the globe potentially amplifying the effects of climate change on biological communities. Ice-free seasons are becoming longer in many areas, which has reduced the time available to polar bears (Ursus maritimus) to hunt for seals and hampered bears’ ability to meet their energetic demands. In this study, we examined polar bears’ use of an ancillary prey resource, eggs of colonial nesting birds, in relation to diminishing sea ice coverage in a low latitude region of the Canadian Arctic. Long-term monitoring reveals that bear incursions onto common eider (Somateria mollissima) and thick-billed murre (Uria lomvia) nesting colonies have increased greater than sevenfold since the 1980s and that there is an inverse correlation between ice season length and bear presence. In surveys encompassing more than 1000 km of coastline during years of record low ice coverage (2010–2012), we encountered bears or bear sign on 34% of eider colonies and estimated greater egg loss as a consequence of depredation by bears than by more customary nest predators, such as foxes and gulls. Our findings demonstrate how changes in abiotic conditions caused by climate change have altered predator–prey dynamics and are leading to cascading ecological impacts in Arctic ecosystems.
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Affiliation(s)
- Samuel A Iverson
- Department of Biology, Carleton University, , Ottawa, Ontario, Canada, Environment Canada-National Wildlife Research Centre, Ottawa, Ontario, Canada
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28
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Zeigler SL, Fagan WF. Transient windows for connectivity in a changing world. MOVEMENT ECOLOGY 2014; 2:1. [PMID: 25520812 PMCID: PMC4267606 DOI: 10.1186/2051-3933-2-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 12/23/2013] [Indexed: 05/22/2023]
Abstract
The primary focus of studies examining metapopulation processes in dynamic or disturbance-dependent landscapes has been related to spatiotemporal changes in the habitat patches themselves. However, like the habitat patches, opportunities for movement between patches can also exist intermittently in dynamic landscapes, creating transient connectivity windows - which we define as a period of time during which matrix conditions increase the probability of one or more individuals moving successfully between habitat patches. Far less is known about the implications of dynamic changes in connectivity per se, and, to our knowledge, there are no connectivity metrics or metapopulation models that explicitly consider intermittent changes to connectivity between habitat patches. Consequently, in this paper, we examined the peer-reviewed, published literature up to November 2013 to better understand the consequences of variability in connectivity and to highlight knowledge gaps on this topic. First, we describe how connectivity per se can vary along a temporal gradient, offering examples of ecological systems that fall along this gradient. Second, we examine how temporal variability in connectivity is important for metapopulation dynamics, particularly given likely alterations to disturbance regimes as a result of global change. We conclude our review by briefly discussing key avenues for future connectivity-related research, all of which hinge on the need to perceive connectivity as a transient feature.
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Affiliation(s)
- Sara L Zeigler
- />Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060 USA
| | - William F Fagan
- />Department of Biology, University of Maryland, College Park, MD 20742 USA
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29
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Mathewson PD, Porter WP. Simulating polar bear energetics during a seasonal fast using a mechanistic model. PLoS One 2013; 8:e72863. [PMID: 24019883 PMCID: PMC3760880 DOI: 10.1371/journal.pone.0072863] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Accepted: 07/21/2013] [Indexed: 11/24/2022] Open
Abstract
In this study we tested the ability of a mechanistic model (Niche Mapper™) to accurately model adult, non-denning polar bear (Ursus maritimus) energetics while fasting during the ice-free season in the western Hudson Bay. The model uses a steady state heat balance approach, which calculates the metabolic rate that will allow an animal to maintain its core temperature in its particular microclimate conditions. Predicted weight loss for a 120 day fast typical of the 1990s was comparable to empirical studies of the population, and the model was able to reach a heat balance at the target metabolic rate for the entire fast, supporting use of the model to explore the impacts of climate change on polar bears. Niche Mapper predicted that all but the poorest condition bears would survive a 120 day fast under current climate conditions. When the fast extended to 180 days, Niche Mapper predicted mortality of up to 18% for males. Our results illustrate how environmental conditions, variation in animal properties, and thermoregulation processes may impact survival during extended fasts because polar bears were predicted to require additional energetic expenditure for thermoregulation during a 180 day fast. A uniform 3°C temperature increase reduced male mortality during a 180 day fast from 18% to 15%. Niche Mapper explicitly links an animal’s energetics to environmental conditions and thus can be a valuable tool to help inform predictions of climate-related population changes. Since Niche Mapper is a generic model, it can make energetic predictions for other species threatened by climate change.
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Affiliation(s)
- Paul D. Mathewson
- Nelson Institute for Environmental Studies, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
| | - Warren P. Porter
- Department of Zoology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Castro de la Guardia L, Derocher AE, Myers PG, Terwisscha van Scheltinga AD, Lunn NJ. Future sea ice conditions in Western Hudson Bay and consequences for polar bears in the 21st century. GLOBAL CHANGE BIOLOGY 2013; 19:2675-87. [PMID: 23716301 DOI: 10.1111/gcb.12272] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 04/19/2013] [Indexed: 05/25/2023]
Abstract
The primary habitat of polar bears is sea ice, but in Western Hudson Bay (WH), the seasonal ice cycle forces polar bears ashore each summer. Survival of bears on land in WH is correlated with breakup and the ice-free season length, and studies suggest that exceeding thresholds in these variables will lead to large declines in the WH population. To estimate when anthropogenic warming may have progressed sufficiently to threaten the persistence of polar bears in WH, we predict changes in the ice cycle and the sea ice concentration (SIC) in spring (the primary feeding period of polar bears) with a high-resolution sea ice-ocean model and warming forced with 21st century IPCC greenhouse gas (GHG) emission scenarios: B1 (low), A1B (medium), and A2 (high). We define critical years for polar bears based on proposed thresholds in breakup and ice-free season and we assess when ice-cycle conditions cross these thresholds. In the three scenarios, critical years occur more commonly after 2050. From 2001 to 2050, 2 critical years occur under B1 and A2, and 4 under A1B; from 2051 to 2100, 8 critical years occur under B1, 35 under A1B and 41 under A2. Spring SIC in WH is high (>90%) in all three scenarios between 2001 and 2050, but declines rapidly after 2050 in A1B and A2. From 2090 to 2100, the mean spring SIC is 84 (±7)% in B1, 56 (±26)% in A1B and 20 (±13)% in A2. Our predictions suggest that the habitat of polar bears in WH will deteriorate in the 21st century. Ice predictions in A1B and A2 suggest that the polar bear population may struggle to persist after ca. 2050. Predictions under B1 suggest that reducing GHG emissions could allow polar bears to persist in WH throughout the 21st century.
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Berry P, Ogawa-Onishi Y, McVey A. The vulnerability of threatened species: adaptive capability and adaptation opportunity. BIOLOGY 2013; 2:872-93. [PMID: 24833051 PMCID: PMC3960872 DOI: 10.3390/biology2030872] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 05/30/2013] [Accepted: 05/31/2013] [Indexed: 11/17/2022]
Abstract
Global targets to halt the loss of biodiversity have not been met, and there is now an additional Aichi target for preventing the extinction of known threatened species and improving their conservation status. Climate change increasingly needs to be factored in to these, and thus there is a need to identify the extent to which it could increase species vulnerability. This paper uses the exposure, sensitivity, and adaptive capacity framework to assess the vulnerability of a selection of WWF global priority large mammals and marine species to climate change. However, it divides adaptive capacity into adaptive capability and adaptation opportunity, in order to identify whether adaptation is more constrained by the biology of the species or by its environmental setting. Lack of evidence makes it difficult to apply the framework consistently across the species, but it was found that, particularly for the terrestrial mammals, adaptation opportunities seems to be the greater constraint. This framework and analysis could be used by conservationists and those wishing to enhance the resilience of species to climate change.
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Affiliation(s)
- Pam Berry
- Environmental Change Institute, University of Oxford, OUCE, South Parks Road, Oxford, OX1 3QY, UK.
| | - Yuko Ogawa-Onishi
- Environmental Change Institute, University of Oxford, OUCE, South Parks Road, Oxford, OX1 3QY, UK.
| | - Andrew McVey
- WWF-UK, Panda House, Weyside Park, Godalming, Surrey GU7 1XR, UK.
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Derocher AE, Aars J, Amstrup SC, Cutting A, Lunn NJ, Molnár PK, Obbard ME, Stirling I, Thiemann GW, Vongraven D, Wiig Ø, York G. Rapid ecosystem change and polar bear conservation. Conserv Lett 2013. [DOI: 10.1111/conl.12009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Andrew E. Derocher
- Department of Biological Sciences, University of Alberta; Edmonton; AB T6G 2E9; Canada
| | - Jon Aars
- Norwegian Polar Institute, Fram Centre; 9296; Tromsø; Norway
| | | | | | - Nick J. Lunn
- Wildlife Research Division, Science and Technology Branch, Environment Canada,; 5320 122 Street; Edmonton; AB T6H 3S5; Canada
| | - Péter K. Molnár
- Ecology and Evolutionary Biology, Eno Hall, Princeton University; Princeton; NJ; 08544-1003; USA
| | - Martyn E. Obbard
- Wildlife Research and Development Section, Ontario Ministry of Natural Resources, DNA Building, Trent University; 2140 East Bank Drive; Peterborough; ON K9J 7B8; Canada
| | | | - Gregory W. Thiemann
- Faculty of Environmental Studies, York University; Toronto; ON; M3J 1P3; Canada
| | - Dag Vongraven
- Norwegian Polar Institute, Fram Centre; 9296; Tromsø; Norway
| | - Øystein Wiig
- National Centre for Biosystematics, Natural History Museum, University of Oslo; PO Box 1172; Blindern 0318 Oslo; Norway
| | - Geoffrey York
- Arctic Species Conservation, WWF Global Arctic Programme; 30 Metcalfe Street; Suite 400; Ottawa; ON K1P 5L4; Canada
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Habitat Isolation Reduces the Temporal Stability of Island Ecosystems in the Face of Flood Disturbance. ADV ECOL RES 2013. [DOI: 10.1016/b978-0-12-417199-2.00004-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Vongraven D, Aars J, Amstrup S, Atkinson SN, Belikov S, Born EW, DeBruyn TD, Derocher AE, Durner G, Gill M, Lunn N, Obbard ME, Omelak J, Ovsyanikov N, Peacock E, Richardson E, Sahanatien V, Stirling I, Wiig Ø. A circumpolar monitoring framework for polar bears. URSUS 2012. [DOI: 10.2192/ursus-d-11-00026.1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Stirling I, Derocher AE. Effects of climate warming on polar bears: a review of the evidence. GLOBAL CHANGE BIOLOGY 2012; 18:2694-706. [PMID: 24501049 DOI: 10.1111/j.1365-2486.2012.02753.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/09/2012] [Accepted: 04/09/2012] [Indexed: 05/25/2023]
Abstract
Climate warming is causing unidirectional changes to annual patterns of sea ice distribution, structure, and freeze-up. We summarize evidence that documents how loss of sea ice, the primary habitat of polar bears (Ursus maritimus), negatively affects their long-term survival. To maintain viable subpopulations, polar bears depend on sea ice as a platform from which to hunt seals for long enough each year to accumulate sufficient energy (fat) to survive periods when seals are unavailable. Less time to access to prey, because of progressively earlier breakup in spring, when newly weaned ringed seal (Pusa hispida) young are available, results in longer periods of fasting, lower body condition, decreased access to denning areas, fewer and smaller cubs, lower survival of cubs as well as bears of other age classes and, finally, subpopulation decline toward eventual extirpation. The chronology of climate-driven changes will vary between subpopulations, with quantifiable negative effects being documented first in the more southerly subpopulations, such as those in Hudson Bay or the southern Beaufort Sea. As the bears' body condition declines, more seek alternate food resources so the frequency of conflicts between bears and humans increases. In the most northerly areas, thick multiyear ice, through which little light penetrates to stimulate biological growth on the underside, will be replaced by annual ice, which facilitates greater productivity and may create habitat more favorable to polar bears over continental shelf areas in the short term. If the climate continues to warm and eliminate sea ice as predicted, polar bears will largely disappear from the southern portions of their range by mid-century. They may persist in the northern Canadian Arctic Islands and northern Greenland for the foreseeable future, but their long-term viability, with a much reduced global population size in a remnant of their former range, is uncertain.
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Affiliation(s)
- Ian Stirling
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
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