1
|
Galicia MP, Thiemann GW, Dyck MG. Correlates of seasonal change in the body condition of an Arctic top predator. GLOBAL CHANGE BIOLOGY 2020; 26:840-850. [PMID: 31465583 DOI: 10.1111/gcb.14817] [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: 07/02/2019] [Accepted: 07/26/2019] [Indexed: 06/10/2023]
Abstract
Climate-driven sea ice loss has led to changes in the timing of key biological events in the Arctic, however, the consequences and rate of these changes remain largely unknown. Polar bears (Ursus maritimus) undergo seasonal changes in energy stores in relation to foraging opportunities and habitat conditions. Declining sea ice has been linked to reduced body condition in some subpopulations, however, the specific timing and duration of the feeding period when bears acquire most of their energy stores and its relationship to the timing of ice break-up is poorly understood. We used community-based sampling to investigate seasonality in body condition (energy stores) of polar bears in Nunavut, Canada, and examined the influence of sea ice variables. We used adipose tissue lipid content as an index of body condition for 1,206 polar bears harvested from 2010-2017 across five subpopulations with varying seasonal ice conditions: Baffin Bay (October-August), Davis Strait and Foxe Basin (year-round), Gulf of Boothia and Lancaster Sound (August-May). Similar seasonal patterns were found in body condition across subpopulations with bears at their nadir of condition in the spring, followed by fat accumulation past break-up date and subsequent peak body condition in autumn, indicating that bears are actively foraging in late spring and early summer. Late season feeding implies that even minor advances in the timing of break-up may have detrimental effects on foraging opportunities, body condition, and subsequent reproduction and survival. The magnitude of seasonal changes in body condition varied across the study area, presumably driven by local environmental conditions. Our results demonstrate how community-based monitoring of polar bears can reveal population-level responses to climate warming in advance of detectable demographic change. Our data on the seasonal timing of polar bear foraging and energy storage should inform predictive models of the effects of climate-mediated sea ice loss.
Collapse
Affiliation(s)
| | | | - Markus G Dyck
- Wildlife Research Station, Department of Environment, Government of Nunavut, Igloolik, NU, Canada
| |
Collapse
|
2
|
Sugianto N, Newman C, Macdonald D, Buesching C. Extrinsic factors affecting cub development contribute to sexual size dimorphism in the European badger (Meles meles). ZOOLOGY 2019; 135:125688. [DOI: 10.1016/j.zool.2019.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 04/27/2019] [Accepted: 04/29/2019] [Indexed: 11/24/2022]
|
3
|
Malenfant RM, Davis CS, Richardson ES, Lunn NJ, Coltman DW. Heritability of body size in the polar bears of Western Hudson Bay. Mol Ecol Resour 2018; 18:854-866. [DOI: 10.1111/1755-0998.12889] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 03/23/2018] [Accepted: 03/29/2018] [Indexed: 12/16/2022]
Affiliation(s)
- René M. Malenfant
- Department of Biology University of New Brunswick Fredericton NB Canada
- Department of Biological Sciences University of Alberta Edmonton Alberta Canada
| | - Corey S. Davis
- Department of Biological Sciences University of Alberta Edmonton Alberta Canada
| | - Evan S. Richardson
- Wildlife Research Division Science and Technology Branch Environment and Climate Change Canada Winnipeg MB Canada
| | - Nicholas J. Lunn
- Wildlife Research Division Science and Technology Branch Environment and Climate Change Canada University of Alberta Edmonton AB Canada
| | - David W. Coltman
- Department of Biological Sciences University of Alberta Edmonton Alberta Canada
| |
Collapse
|
4
|
Daugaard-Petersen T, Langebæk R, Rigét FF, Dyck M, Letcher RJ, Hyldstrup L, Jensen JEB, Dietz R, Sonne C. Persistent organic pollutants and penile bone mineral density in East Greenland and Canadian polar bears (Ursus maritimus) during 1996-2015. ENVIRONMENT INTERNATIONAL 2018; 114:212-218. [PMID: 29522985 DOI: 10.1016/j.envint.2018.02.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 02/11/2018] [Accepted: 02/11/2018] [Indexed: 05/20/2023]
Abstract
Persistent organic pollutants (POPs) are long-range transported to the Arctic via atmospheric and oceanic currents, where they biomagnify to high concentrations in the tissues of apex predators such as polar bears (Ursus maritimus). A major concern of POP exposure is their physiological effects on vital organ-tissues posing a threat to the health and survival of polar bears. Here we examined the relationship between selected POPs and baculum bone mineral density (BMD) in the East Greenland and seven Canadian subpopulations of polar bears. BMD was examined in 471 bacula collected between years 1996-2015 while POP concentrations in adipose tissue were determined in 67-192 of these individuals collected from 1999 to -2015. A geographical comparison showed that baculum BMD was significantly lowest in polar bears from East Greenland (EG) when compared to Gulf of Boothia (GB), Southern Hudson (SH) and Western Hudson (WH) Bay subpopulations (all p < 0.05). The calculation of a T-score osteoporosis index for the EG subpopulation using WH bears as a reference group gave a T-score of -1.44 which indicate risk of osteopenia. Concentrations of ΣPCB74 (polychlorinated biphenyls), ΣDDT3 (dichlorodiphenyltrichloroethanes), p,p'-DDE (dichlorodiphenyldichloroethylene), ΣHCH3 (hexachlorohexane) and α-HCH was significantly highest in EG bears while ΣPBDE (polybrominated diphenyl ethers), BDE-47 and BDE-153 was significantly highest in SH bears (all p < 0.04). Statistical analyses of individual baculum BMD vs. POP concentrations showed that BMD was positively correlated with ΣPCB74, CB-153, HCB (hexachlorobenzene), ΣHCH, β-HCH, ClBz (chlorobenzene), ΣPBDE and BDE-153 (all p < 0.03). In conclusion, baculum density was significantly lowest in East Greenland polar bears despite the positive statistical correlations of BMD vs. POPs. Other important factors such as nutritional status, body mass and body condition was not available for the statistical modelling. Since on-going environmental changes are known to affect these, future studies need to incorporate nutritional, endocrine and genetic parameters to further understand how POP exposure may disrupt bone homeostasis and affect baculum BMD across polar bear subpopulations.
Collapse
Affiliation(s)
- Tobias Daugaard-Petersen
- Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Rikke Langebæk
- University of Copenhagen, Faculty of Health and Medical Sciences, Department of Veterinary Clinical and Animal Sciences, Dyrlægevej 16, 1-72, DK-1870 Frederiksberg C, Denmark.
| | - Frank F Rigét
- Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark.
| | - Markus Dyck
- Wildlife Management Division, Department of Environment, Government of Nunavut, PO Box 209, Igloolik, NU X0A 0L0, Canada.
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada.
| | - Lars Hyldstrup
- University Hospital of Hvidovre, Kettegaards Allé 30, DK-2650 Hvidovre, Denmark.
| | | | - Rune Dietz
- Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark.
| | - Christian Sonne
- Aarhus University, Faculty of Science and Technology, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark.
| |
Collapse
|
5
|
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
| | | |
Collapse
|
6
|
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]
|
7
|
Nielsen SE, Cattet MRL, Boulanger J, Cranston J, McDermid GJ, Shafer ABA, Stenhouse GB. Environmental, biological and anthropogenic effects on grizzly bear body size: temporal and spatial considerations. BMC Ecol 2013; 13:31. [PMID: 24010501 PMCID: PMC3849066 DOI: 10.1186/1472-6785-13-31] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 09/06/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Individual body growth is controlled in large part by the spatial and temporal heterogeneity of, and competition for, resources. Grizzly bears (Ursus arctos L.) are an excellent species for studying the effects of resource heterogeneity and maternal effects (i.e. silver spoon) on life history traits such as body size because their habitats are highly variable in space and time. Here, we evaluated influences on body size of grizzly bears in Alberta, Canada by testing six factors that accounted for spatial and temporal heterogeneity in environments during maternal, natal and 'capture' (recent) environments. After accounting for intrinsic biological factors (age, sex), we examined how body size, measured in mass, length and body condition, was influenced by: (a) population density; (b) regional habitat productivity; (c) inter-annual variability in productivity (including silver spoon effects); (d) local habitat quality; (e) human footprint (disturbances); and (f) landscape change. RESULTS We found sex and age explained the most variance in body mass, condition and length (R(2) from 0.48-0.64). Inter-annual variability in climate the year before and of birth (silver spoon effects) had detectable effects on the three-body size metrics (R(2) from 0.04-0.07); both maternal (year before birth) and natal (year of birth) effects of precipitation and temperature were related with body size. Local heterogeneity in habitat quality also explained variance in body mass and condition (R(2) from 0.01-0.08), while annual rate of landscape change explained additional variance in body length (R(2) of 0.03). Human footprint and population density had no observed effect on body size. CONCLUSIONS These results illustrated that body size patterns of grizzly bears, while largely affected by basic biological characteristics (age and sex), were also influenced by regional environmental gradients the year before, and of, the individual's birth thus illustrating silver spoon effects. The magnitude of the silver spoon effects was on par with the influence of contemporary regional habitat productivity, which showed that both temporal and spatial influences explain in part body size patterns in grizzly bears. Because smaller bears were found in colder and less-productive environments, we hypothesize that warming global temperatures may positively affect body mass of interior bears.
Collapse
Affiliation(s)
- Scott E Nielsen
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta T6G 2H1, Canada
| | - Marc RL Cattet
- Canadian Cooperative Wildlife Health Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada
| | - John Boulanger
- Integrated Ecological Research, Nelson, BC V1L 5T2, Canada
| | | | - Greg J McDermid
- Department of Geography, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Aaron BA Shafer
- Department of Ecology and Genetics, Uppsala University, Uppsala, SE 75240, Sweden
| | | |
Collapse
|
8
|
Macbeth BJ, Cattet MRL, Obbard ME, Middel K, Janz DM. Evaluation of hair cortisol concentration as a biomarker of long-term stress in free-ranging polar bears. WILDLIFE SOC B 2012. [DOI: 10.1002/wsb.219] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
9
|
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]
|
10
|
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.
Collapse
Affiliation(s)
- Ian Stirling
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | | |
Collapse
|
11
|
Rode KD, Amstrup SC, Regehr EV. Reduced body size and cub recruitment in polar bears associated with sea ice decline. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2010; 20:768-782. [PMID: 20437962 DOI: 10.1890/08-1036.1] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Rates of reproduction and survival are dependent upon adequate body size and condition of individuals. Declines in size and condition have provided early indicators of population decline in polar bears (Ursus maritimus) near the southern extreme of their range. We tested whether patterns in body size, condition, and cub recruitment of polar bears in the southern Beaufort Sea of Alaska were related to the availability of preferred sea ice habitats and whether these measures and habitat availability exhibited trends over time, between 1982 and 2006. The mean skull size and body length of all polar bears over three years of age declined over time, corresponding with long-term declines in the spatial and temporal availability of sea ice habitat. Body size of young, growing bears declined over time and was smaller after years when sea ice availability was reduced. Reduced litter mass and numbers of yearlings per female following years with lower availability of optimal sea ice habitat, suggest reduced reproductive output and juvenile survival. These results, based on analysis of a long-term data set, suggest that declining sea ice is associated with nutritional limitations that reduced body size and reproduction in this population.
Collapse
Affiliation(s)
- Karyn D Rode
- U.S. Fish and Wildlife Service, Marine Mammals Management, 1011 East Tudor Road, Anchorage, Alaska 99503, USA.
| | | | | |
Collapse
|
12
|
Derocher AE, Andersen M, Wiig Ø, Aars J. Sexual dimorphism and the mating ecology of polar bears (Ursus maritimus) at Svalbard. Behav Ecol Sociobiol 2010. [DOI: 10.1007/s00265-010-0909-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Molnár PK, Klanjscek T, Derocher AE, Obbard ME, Lewis MA. A body composition model to estimate mammalian energy stores and metabolic rates from body mass and body length, with application to polar bears. J Exp Biol 2009; 212:2313-23. [DOI: 10.1242/jeb.026146] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Many species experience large fluctuations in food availability and depend on energy from fat and protein stores for survival, reproduction and growth. Body condition and, more specifically, energy stores thus constitute key variables in the life history of many species. Several indices exist to quantify body condition but none can provide the amount of stored energy. To estimate energy stores in mammals, we propose a body composition model that differentiates between structure and storage of an animal. We develop and parameterize the model specifically for polar bears (Ursus maritimus Phipps)but all concepts are general and the model could be easily adapted to other mammals. The model provides predictive equations to estimate structural mass,storage mass and storage energy from an appropriately chosen measure of body length and total body mass. The model also provides a means to estimate basal metabolic rates from body length and consecutive measurements of total body mass. Model estimates of body composition, structural mass, storage mass and energy density of 970 polar bears from Hudson Bay were consistent with the life history and physiology of polar bears. Metabolic rate estimates of fasting adult males derived from the body composition model corresponded closely to theoretically expected and experimentally measured metabolic rates. Our method is simple, non-invasive and provides considerably more information on the energetic status of individuals than currently available methods.
Collapse
Affiliation(s)
- Péter K. Molnár
- Centre for Mathematical Biology, Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, Canada T6G 2G1
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Tin Klanjscek
- Department for Marine and Environmental Research, Ruder BoškovićInstitute, POB. 180, Bijenička 54, HR-10002 Zagreb, Croatia
| | - Andrew E. Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Martyn E. Obbard
- Wildlife Research and Development Section, Ontario Ministry of Natural Resources, DNA Building, Trent University, 2140 East Bank Drive, Peterborough,ON, Canada K9J 7B8
| | - Mark A. Lewis
- Centre for Mathematical Biology, Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, Canada T6G 2G1
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| |
Collapse
|
14
|
Thiemann GW, Iverson SJ, Stirling I. POLAR BEAR DIETS AND ARCTIC MARINE FOOD WEBS: INSIGHTS FROM FATTY ACID ANALYSIS. ECOL MONOGR 2008. [DOI: 10.1890/07-1050.1] [Citation(s) in RCA: 253] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
15
|
Cattet M, Boulanger J, Stenhouse G, Powell RA, Reynolds-Hogland MJ. An Evaluation of Long-Term Capture Effects in Ursids: Implications for Wildlife Welfare and Research. J Mammal 2008. [DOI: 10.1644/08-mamm-a-095.1] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
16
|
Bechshøft TØ, Sonne C, Rigét FF, Wiig Ø, Dietz R. Differences in growth, size and sexual dimorphism in skulls of East Greenland and Svalbard polar bears (Ursus maritimus). Polar Biol 2008. [DOI: 10.1007/s00300-008-0435-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
17
|
Dahle B, Zedrosser A, Swenson JE. Correlates with body size and mass in yearling brown bears (Ursus arctos). J Zool (1987) 2006. [DOI: 10.1111/j.1469-7998.2006.00127.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
18
|
|
19
|
|
20
|
Growth and variation in the bacula of polar bears (Ursus maritimus) in the Canadian Arctic. J Zool (1987) 2004. [DOI: 10.1017/s0952836904005606] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
21
|
|
22
|
Derocher AE, Stirling I. Maternal investment and factors affecting offspring size in polar bears (Ursus maritimus). J Zool (1987) 1998. [DOI: 10.1111/j.1469-7998.1998.tb00099.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
23
|
|