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Webber QMR, Laforge MP, Bonar M, Vander Wal E. The adaptive value of density-dependent habitat specialization and social network centrality. Nat Commun 2024; 15:4423. [PMID: 38789438 PMCID: PMC11126670 DOI: 10.1038/s41467-024-48657-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Density dependence is a fundamental ecological process. In particular, animal habitat selection and social behavior often affect fitness in a density-dependent manner. The Ideal Free Distribution (IFD) and niche variation hypothesis (NVH) present distinct predictions associated with Optimal Foraging Theory about how the effect of habitat selection on fitness varies with population density. Using caribou (Rangifer tarandus) in Canada as a model system, we test competing hypotheses about how habitat specialization, social behavior, and annual reproductive success (co)vary across a population density gradient. Within a behavioral reaction norm framework, we estimate repeatability, behavioral plasticity, and covariance among social behavior and habitat selection to investigate the adaptive value of sociality and habitat selection. In support of NVH, but not the IFD, we find that at high density habitat specialists had higher annual reproductive success than generalists, but were also less social than generalists, suggesting the possibility that specialists were less social to avoid competition. Our study supports niche variation as a mechanism for density-dependent habitat specialization.
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Affiliation(s)
- Quinn M R Webber
- Cognitive and Behavioural Ecology Interdisciplinary Program, Memorial University of Newfoundland, St. John's, NF, Canada.
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada.
| | - Michel P Laforge
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Maegwin Bonar
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Eric Vander Wal
- Cognitive and Behavioural Ecology Interdisciplinary Program, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
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2
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St-Laurent MH, Boulanger Y, Cyr D, Manka F, Drapeau P, Gauthier S. Lowering the rate of timber harvesting to mitigate impacts of climate change on boreal caribou habitat quality in eastern Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156244. [PMID: 35636534 DOI: 10.1016/j.scitotenv.2022.156244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 05/09/2022] [Accepted: 05/22/2022] [Indexed: 06/15/2023]
Abstract
Many boreal populations of woodland caribou (Rangifer tarandus caribou) have declined in Canada, a trend essentially driven by the increasing footprint of anthropogenic disturbances and the resulting habitat-mediated apparent competition that increases predation pressure. However, the influence of climate change on these ecological processes remains poorly understood. We evaluated how climate change will affect boreal caribou habitat over the 2030-2100 horizon and in a 9.94 Mha study area, using a climate-sensitive simulation ensemble that integrates climate-induced changes in stand dynamics, fire regime, and different levels of commercial timber harvesting. We assessed the relative importance of these three drivers under projections made using different radiative forcing scenarios (RCP 2.6, 4.5, 8.5). Habitat quality was estimated from resource selection functions built with telemetry data collected from 121 caribou between 2004 and 2011 in 7 local populations. At the beginning of our simulations, caribou habitat was already structured along a south-to-north increasing quality gradient. Simulations revealed changes in forest cover that are driven by climate-induced variations in fire regime and scenarios of harvesting levels, resulting in the loss of older coniferous forests and an increase in deciduous stands. These changes induced a generalized decrease in the average habitat quality and in the percentage of high-quality habitat for caribou, and in a northward recession of suitable habitat. Timber harvesting was the most important agent of change for the 2030-2050 horizon, although it was slowly replaced by changes in fire regime until 2100. Our results clearly showed that it is possible to maintain the current average habitat quality for caribou in future scenarios that consider a reduction in harvested volumes, the only lever under our control. This suggests that we still have the capacity to conciliate socioeconomic development and caribou conservation imperatives in the face of climate change, an important issue debated throughout the species distribution range.
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Affiliation(s)
- Martin-Hugues St-Laurent
- Département de biologie, chimie et géographie, Centre for Forest Research, Centre for Northern Studies, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, Québec G5L 3A1, Canada.
| | - Yan Boulanger
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, Québec G1V 4C7, Canada
| | - Dominic Cyr
- Environment and Climate Change Canada, Science and Technology Branch, 351 Boulevard Saint-Joseph, Gatineau, Quebec J8Y 3Z5, Canada
| | - Francis Manka
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, Québec G1V 4C7, Canada
| | - Pierre Drapeau
- Département des sciences biologiques, Centre for Forest Research, UQAT-UQAM Research Chair in Sustainable Forest Management, Université du Québec à Montréal, 141 Avenue du Président-Kennedy, Montréal, Québec H2X 1Y4, Canada
| | - Sylvie Gauthier
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, Québec G1V 4C7, Canada
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3
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Wan X, Holyoak M, Yan C, Le Maho Y, Dirzo R, Krebs CJ, Stenseth NC, Zhang Z. Broad-scale climate variation drives the dynamics of animal populations: a global multi-taxa analysis. Biol Rev Camb Philos Soc 2022; 97:2174-2194. [PMID: 35942895 DOI: 10.1111/brv.12888] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 01/07/2023]
Abstract
Climate is a major extrinsic factor affecting the population dynamics of many organisms. The Broad-Scale Climate Hypothesis (BSCH) was proposed by Elton to explain the large-scale synchronous population cycles of animals, but the extent of support and whether it differs among taxa and geographical regions is unclear. We reviewed publications examining the relationship between the population dynamics of multiple taxa worldwide and the two most commonly used broad-scale climate indices, El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO). Our review and synthesis (based on 561 species from 221 papers) reveals that population changes of mammals, birds and insects are strongly affected by major oceanic shifts or irregular oceanic changes, particularly in ENSO- and NAO-influenced regions (Pacific and Atlantic, respectively), providing clear evidence supporting Elton's BSCH. Mammal and insect populations tended to increase during positive ENSO phases. Bird populations tended to increase in positive NAO phases. Some species showed dual associations with both positive and negative phases of the same climate index (ENSO or NAO). These findings indicate that some taxa or regions are more or less vulnerable to climate fluctuations and that some geographical areas show multiple weather effects related to ENSO or NAO phases. Beyond confirming that animal populations are influenced by broad-scale climate variation, we document extensive patterns of variation among taxa and observe that the direct biotic and abiotic mechanisms for these broad-scale climate factors affecting animal populations are very poorly understood. A practical implication of our research is that changes in ENSO or NAO can be used as early signals for pest management and wildlife conservation. We advocate integrative studies at both broad and local scales to unravel the omnipresent effects of climate on animal populations to help address the challenge of conserving biodiversity in this era of accelerated climate change.
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Affiliation(s)
- Xinru Wan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Marcel Holyoak
- Department of Environmental Science and Policy, University of California, California, Davis, 95616, USA
| | - Chuan Yan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yvon Le Maho
- Institut Pluridisciplinaire Hubert Curien (IPHC), Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, 67000, France.,Centre Scientifique de Monaco, Monaco, 98000, Monaco
| | - Rodolfo Dirzo
- Department of Biology and Woods Institute for the Environment, Stanford University, Stanford, California, 94305, USA
| | - Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, N-0316, Norway
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
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McNamara JA, Schaefer JA, Bastille-Rousseau G, Mahoney SP. Landscape features and caribou harvesting during three decades in Newfoundland. ECOSCIENCE 2022. [DOI: 10.1080/11956860.2021.1969825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Jordan A. McNamara
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada
| | - James A. Schaefer
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | | | - Shane P. Mahoney
- Conservation Visions Inc., St. John’s, Newfoundland & Labrador, Canada
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Pugesek G, Mumma MA, Mahoney SP, Waits LP. Molecular evaluation of American black bear prey consumption following diversionary feeding. URSUS 2021. [DOI: 10.2192/ursus-d-20-00027.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Genevieve Pugesek
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA
| | - Matthew A. Mumma
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA
| | - Shane P. Mahoney
- Department of Environment and Conservation, Government of Newfoundland and Labrador, St. John's, Newfoundland A1B 4J6, Canada
| | - Lisette P. Waits
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA
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6
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Webber QMR, Vander Wal E. Context-dependent group size: effects of population density, habitat, and season. Behav Ecol 2021. [DOI: 10.1093/beheco/arab070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Group size can vary in relation to population density, habitat, and season. Habitat and season may also interact with population density and affect group size through varying foraging benefits of social aggregation in different ecological contexts. We tested the hypothesis that group size varies across ecological contexts, including population density, habitat type, and season, for woodland caribou (Rangifer tarandus) in ten herds over 25 years in Newfoundland, Canada. We predicted that group size would increase as a function of population density. Based on the foraging benefits of social aggregation, we predicted larger groups as habitat openness increased because open areas tend to have higher quality foraging resources. We predicted larger groups during winter when foraging resources are covered in snow because caribou and other social animals exploit social information about the location of foraging resources. In contrast to our prediction, group size decreased as a function of population density. In support of our prediction, group size was larger in winter than calving and summer, and we found that group size increased with habitat openness in some, but not all, cases. Patterns of animal grouping are context-dependent and the additive effect of different ecological contexts on variation in group size informs our understanding of the implicit trade-offs between competition, predation risk, and profitability of forage.
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Affiliation(s)
- Quinn M R Webber
- Cognitive and Behavioural Ecology Interdisciplinary Program, Memorial University of Newfoundland, 232 Elizabeth Ave, St. John’s, NL A1B 3X9, Canada
| | - Eric Vander Wal
- Cognitive and Behavioural Ecology Interdisciplinary Program, Memorial University of Newfoundland, 232 Elizabeth Ave, St. John’s, NL A1B 3X9, Canada
- Department of Biology, Memorial University of Newfoundland, 232 Elizabeth Ave, St. John’s, NL A1B 3X9,Canada
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Ellington EH, Lewis KP, Koen EL, Vander Wal E. Divergent estimates of herd-wide caribou calf survival: Ecological factors and methodological biases. Ecol Evol 2020; 10:8476-8505. [PMID: 32788995 PMCID: PMC7417224 DOI: 10.1002/ece3.6553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 06/01/2020] [Accepted: 06/10/2020] [Indexed: 11/11/2022] Open
Abstract
Population monitoring is a critical part of effective wildlife management, but methods are prone to biases that can hinder our ability to accurately track changes in populations through time. Calf survival plays an important role in ungulate population dynamics and can be monitored using telemetry and herd composition surveys. These methods, however, are susceptible to unrepresentative sampling and violations of the assumption of equal detectability, respectively. Here, we capitalized on 55 herd-wide estimates of woodland caribou (Rangifer tarandus caribou) calf survival in Newfoundland, Canada, using telemetry (n = 1,175 calves) and 249 herd-wide estimates of calf:cow ratios (C:C) using herd composition surveys to investigate these potential biases. These data included 17 herd-wide estimates replicated from both methods concurrently (n = 448 calves and n = 17 surveys) which we used to understand which processes and sampling biases contributed to disagreement between estimates of herd-wide calf survival. We used Cox proportional hazards models to determine whether estimates of calf mortality risk were biased by the date a calf was collared. We also used linear mixed-effects models to determine whether estimates of C:C ratios were biased by survey date and herd size. We found that calves collared later in the calving season had a higher mortality risk and that C:C tended to be higher for surveys conducted later in the autumn. When we used these relationships to modify estimates of herd-wide calf survival derived from telemetry and herd composition surveys concurrently, we found that formerly disparate estimates of woodland caribou calf survival now overlapped (within a 95% confidence interval) in a majority of cases. Our case study highlights the potential of under-appreciated biases to impact our understanding of population dynamics and suggests ways that managers can limit the influence of these biases in the two widely applied methods for estimating herd-wide survival.
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Affiliation(s)
- E. Hance Ellington
- School of Environment and Natural ResourcesOhio State UniversityColumbusOHUSA
- Department of BiologyMemorial University of NewfoundlandSt. John’sNFCanada
| | - Keith P. Lewis
- Department of BiologyMemorial University of NewfoundlandSt. John’sNFCanada
- Northwest Atlantic Fisheries CentreFisheries and Oceans CanadaSt. John’sNFCanada
| | - Erin L. Koen
- Department of BiologyMemorial University of NewfoundlandSt. John’sNFCanada
- Wildlife Research and Monitoring SectionOntario Ministry of Natural Resources and ForestryPeterboroughONCanada
| | - Eric Vander Wal
- Department of BiologyMemorial University of NewfoundlandSt. John’sNFCanada
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Webber QMR, Laforge MP, Bonar M, Robitaille AL, Hart C, Zabihi-Seissan S, Vander Wal E. The Ecology of Individual Differences Empirically Applied to Space-Use and Movement Tactics. Am Nat 2020; 196:E1-E15. [PMID: 32552106 DOI: 10.1086/708721] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Movement provides a link between individual behavioral ecology and the spatial and temporal variation in an individual's landscape. Individual variation in movement traits is an important axis of animal personality, particularly in the context of foraging ecology. We tested whether individual caribou (Rangifer tarandus) displayed plasticity in movement and space-use behavior across a gradient of resource aggregation. We quantified first-passage time and range-use ratio as proxies for movement-related foraging behavior and examined how these traits varied at the individual level across a foraging resource gradient. Our results suggest that individuals adjusted first-passage time but not range-use ratio to maximize access to high-quality foraging resources. First-passage time was repeatable, and intercepts for first-passage time and range-use ratio were negatively correlated. Individuals matched first-passage time but not range-use ratio to the expectations of our patch-use model that maximized access to foraging resources, a result that suggests that individuals acclimated their movement patterns to accommodate both intra- and interannual variation in foraging resources on the landscape. Collectively, we highlight repeatable movement and space-use tactics and provide insight into how individual plasticity in movement interacts with landscape processes to affect the distribution of behavioral phenotypes and potentially fitness and population dynamics.
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Mumma MA, Bastille-Rousseau G, Gullage SE, Soulliere CE, Mahoney SP, Waits LP. Intrinsic traits of woodland caribou Rangifer tarandus caribou calves depredated by black bears Ursus americanus and coyotes Canis latrans. WILDLIFE BIOLOGY 2019. [DOI: 10.2981/wlb.00494] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Matthew A. Mumma
- M. A. Mumma (http://orcid.org/0000-0003-1954-6524) , Ecosystem Science and Management, Univ. of Northern British Columbia, 3333 University Way, Prince George, BC, V2N 4Z9, Canada
| | - Guillaume Bastille-Rousseau
- G. Bastille-Rousseau, Dept of Fish, Wildlife and Conservation Biology, Colorado State Univ., Fort Collins, CO, USA
| | - Steve E. Gullage
- S. E. Gullage and S. P. Mahoney, Conservation Visions, LLC, St. John's, NL, Canada
| | - Colleen E. Soulliere
- C. E. Soulliere, Dept of Environment and Conservation, Government of Newfoundland and Labrador, St. John's, NL, Canada
| | - Shane P. Mahoney
- S. E. Gullage and S. P. Mahoney, Conservation Visions, LLC, St. John's, NL, Canada
| | - Lisette P. Waits
- L. P. Waits, Dept of Fish and Wildlife Sciences, Univ. of Idaho, Moscow, ID, USA
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Peignier M, Webber QMR, Koen EL, Laforge MP, Robitaille AL, Vander Wal E. Space use and social association in a gregarious ungulate: Testing the conspecific attraction and resource dispersion hypotheses. Ecol Evol 2019; 9:5133-5145. [PMID: 31110667 PMCID: PMC6509382 DOI: 10.1002/ece3.5071] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/27/2019] [Accepted: 02/07/2019] [Indexed: 11/11/2022] Open
Abstract
Animals use a variety of proximate cues to assess habitat quality when resources vary spatiotemporally. Two nonmutually exclusive strategies to assess habitat quality involve either direct assessment of landscape features or observation of social cues from conspecifics as a form of information transfer about forage resources. The conspecific attraction hypothesis proposes that individual space use is dependent on the distribution of conspecifics rather than the location of resource patches, whereas the resource dispersion hypothesis proposes that individual space use and social association are driven by the abundance and distribution of resources. We tested the conspecific attraction and the resource dispersion hypotheses as two nonmutually exclusive hypotheses explaining social association and of adult female caribou (Rangifer tarandus). We used location data from GPS collars to estimate interannual site fidelity and networks representing home range overlap and social associations among individual caribou. We found that home range overlap and social associations were correlated with resource distribution in summer and conspecific attraction in winter. In summer, when resources were distributed relatively homogeneously, interannual site fidelity was high and home range overlap and social associations were low. Conversely, in winter when resources were distributed relatively heterogeneously, interannual site fidelity was low and home range overlap and social associations were high. As access to resources changes across seasons, caribou appear to alter social behavior and space use. In summer, caribou may use cues associated with the distribution of forage, and in winter caribou may use cues from conspecifics to access forage. Our results have broad implications for our understanding of caribou socioecology, suggesting that caribou use season-specific strategies to locate forage. Caribou populations continue to decline globally, and our finding that conspecific attraction is likely related to access to forage suggests that further fragmentation of caribou habitat could limit social association among caribou, particularly in winter when access to resources may be limited.
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Affiliation(s)
- Mélissa Peignier
- Department of BiologyMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
| | - Quinn M. R. Webber
- Cognitive and Behavioural Ecology Interdisciplinary ProgramMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
| | - Erin L. Koen
- Department of BiologyMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
| | - Michel P. Laforge
- Department of BiologyMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
| | - Alec L. Robitaille
- Department of BiologyMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
| | - Eric Vander Wal
- Department of BiologyMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
- Cognitive and Behavioural Ecology Interdisciplinary ProgramMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
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Bonar M, Ellington EH, Lewis KP, Vander Wal E. Implementing a novel movement-based approach to inferring parturition and neonate caribou calf survival. PLoS One 2018; 13:e0192204. [PMID: 29466451 PMCID: PMC5821316 DOI: 10.1371/journal.pone.0192204] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/19/2018] [Indexed: 11/18/2022] Open
Abstract
In ungulates, parturition is correlated with a reduction in movement rate. With advances in movement-based technologies comes an opportunity to develop new techniques to assess reproduction in wild ungulates that are less invasive and reduce biases. DeMars et al. (2013, Ecology and Evolution 3:4149-4160) proposed two promising new methods (individual- and population-based; the DeMars model) that use GPS inter-fix step length of adult female caribou (Rangifer tarandus caribou) to infer parturition and neonate survival. Our objective was to apply the DeMars model to caribou populations that may violate model assumptions for retrospective analysis of parturition and calf survival. We extended the use of the DeMars model after assigning parturition and calf mortality status by examining herd-wide distributions of parturition date, calf mortality date, and survival. We used the DeMars model to estimate parturition and calf mortality events and compared them with the known parturition and calf mortality events from collared adult females (n = 19). We also used the DeMars model to estimate parturition and calf mortality events for collared female caribou with unknown parturition and calf mortality events (n = 43) and instead derived herd-wide estimates of calf survival as well as distributions of parturition and calf mortality dates and compared them to herd-wide estimates generated from calves fitted with VHF collars (n = 134). For our data, the individual-based method was effective at predicting calf mortality, but was not effective at predicting parturition. The population-based method was more effective at predicting parturition but was not effective at predicting calf mortality. At the herd-level, the predicted distributions of parturition date from both methods differed from each other and from the distribution derived from the parturition dates of VHF-collared calves (log-ranked test: χ2 = 40.5, df = 2, p < 0.01). The predicted distributions of calf mortality dates from both methods were similar to the observed distribution derived from VHF-collared calves. Both methods underestimated herd-wide calf survival based on VHF-collared calves, however, a combination of the individual- and population-based methods produced herd-wide survival estimates similar to estimates generated from collared calves. The limitations we experienced when applying the DeMars model could result from the shortcomings in our data violating model assumptions. However despite the differences in our caribou systems, with proper validation techniques the framework in the DeMars model is sufficient to make inferences on parturition and calf mortality.
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Affiliation(s)
- Maegwin Bonar
- Department of Biology, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
| | - E. Hance Ellington
- Department of Biology, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
- School of Environment and Natural Resources, Ohio State University, Columbus, Ohio, United States of America
| | - Keith P. Lewis
- Department of Biology, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
- Department of Fisheries and Oceans, St. John’s, Newfoundland and Labrador, Canada
| | - Eric Vander Wal
- Department of Biology, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
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Bastille-Rousseau G, Schaefer JA, Peers MJL, Ellington EH, Mumma MA, Rayl ND, Mahoney SP, Murray DL. Climate change can alter predator–prey dynamics and population viability of prey. Oecologia 2017; 186:141-150. [DOI: 10.1007/s00442-017-4017-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 11/16/2017] [Indexed: 10/18/2022]
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13
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Lewis KP, Gullage SE, Fifield DA, Jennings DH, Mahoney SP. Manipulations of black bear and coyote affect caribou calf survival. J Wildl Manage 2016. [DOI: 10.1002/jwmg.21174] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Keith P. Lewis
- Sustainable Development and Strategic Science, Department of Environment and Conservation; Government of Newfoundland and Labrador; St. John's NL A1B 4J6 Canada
| | - Stephen E. Gullage
- Sustainable Development and Strategic Science, Department of Environment and Conservation; Government of Newfoundland and Labrador; St. John's NL A1B 4J6 Canada
| | - David A. Fifield
- Sustainable Development and Strategic Science, Department of Environment and Conservation; Government of Newfoundland and Labrador; St. John's NL A1B 4J6 Canada
| | - David H. Jennings
- Agrifoods-Production & Market Development, Department of Natural Resources; Government of Newfoundland and Labrador; PO Box 2006 Corner Brook NL A2H 6J8 Canada
| | - Shane P. Mahoney
- Sustainable Development and Strategic Science, Department of Environment and Conservation; Government of Newfoundland and Labrador; St. John's NL A1B 4J6 Canada
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Uboni A, Horstkotte T, Kaarlejärvi E, Sévêque A, Stammler F, Olofsson J, Forbes BC, Moen J. Long-Term Trends and Role of Climate in the Population Dynamics of Eurasian Reindeer. PLoS One 2016; 11:e0158359. [PMID: 27362499 PMCID: PMC4928808 DOI: 10.1371/journal.pone.0158359] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 06/14/2016] [Indexed: 11/22/2022] Open
Abstract
Temperature is increasing in Arctic and sub-Arctic regions at a higher rate than anywhere else in the world. The frequency and nature of precipitation events are also predicted to change in the future. These changes in climate are expected, together with increasing human pressures, to have significant impacts on Arctic and sub-Arctic species and ecosystems. Due to the key role that reindeer play in those ecosystems, it is essential to understand how climate will affect the region’s most important species. Our study assesses the role of climate on the dynamics of fourteen Eurasian reindeer (Rangifer tarandus) populations, using for the first time data on reindeer abundance collected over a 70-year period, including both wild and semi-domesticated reindeer, and covering more than half of the species’ total range. We analyzed trends in population dynamics, investigated synchrony among population growth rates, and assessed the effects of climate on population growth rates. Trends in the population dynamics were remarkably heterogeneous. Synchrony was apparent only among some populations and was not correlated with distance among population ranges. Proxies of climate variability mostly failed to explain population growth rates and synchrony. For both wild and semi-domesticated populations, local weather, biotic pressures, loss of habitat and human disturbances appear to have been more important drivers of reindeer population dynamics than climate. In semi-domesticated populations, management strategies may have masked the effects of climate. Conservation efforts should aim to mitigate human disturbances, which could exacerbate the potentially negative effects of climate change on reindeer populations in the future. Special protection and support should be granted to those semi-domesticated populations that suffered the most because of the collapse of the Soviet Union, in order to protect the livelihood of indigenous peoples that depend on the species, and the multi-faceted role that reindeer exert in Arctic ecosystems.
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Affiliation(s)
- Alessia Uboni
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
- * E-mail:
| | - Tim Horstkotte
- Department of Geography and Geology, University of Turku, Turku, Finland
| | - Elina Kaarlejärvi
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
- Plant Biology and Nature Management, Vrije Universiteit Brussel, Brussels, Belgium
| | - Anthony Sévêque
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | | | - Johan Olofsson
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | | | - Jon Moen
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
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Bastille-Rousseau G, Rayl ND, Ellington EH, Schaefer JA, Peers MJ, Mumma MA, Mahoney SP, Murray DL. Temporal variation in habitat use, co-occurrence, and risk among generalist predators and a shared prey. CAN J ZOOL 2016. [DOI: 10.1139/cjz-2015-0127] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Generalist predators typically have broad diets, but their diets may become constrained when one species of prey becomes disproportionately available. Yet there is poor understanding regarding whether generalist predators exhibit stereotypic relationships with pulsed prey resources. We used telemetry data from 959 woodland caribou (Rangifer tarandus caribou (Gmelin, 1788); 146 adult females, 813 calves), 61 coyotes (Canis latrans Say, 1823), and 55 black bears (Ursus americanus Pallas, 1780) to investigate how two generalist predators interacted with caribou neonates on the island of Newfoundland. We examined the similarity of patterns of habitat use between caribou and their predators across time and related this similarity to interspecific spatiotemporal co-occurrence and mortality risk for caribou neonates. The similarity in habitat use between coyotes and caribou mirrored variation in juvenile hazard risk, but had weak association with actual co-occurrence with caribou. Bears and caribou exhibited less similarity in habitat use during the calving season than coyotes and caribou. The relationship between habitat use of bear and caribou did not correspond with either co-occurrence patterns or overall risk for caribou neonates. Our work illustrates how risk for a prey species can be shaped differently based upon differences between the behavioural strategies of generalist predator species.
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Affiliation(s)
| | - Nathaniel D. Rayl
- Department of Environmental Conservation, University of Massachusetts, Amherst, MA 01003, USA
| | - E. Hance Ellington
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9J 7B8, Canada
| | - James A. Schaefer
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9J 7B8, Canada
| | - Michael J.L. Peers
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9J 7B8, Canada
| | - Matthew A. Mumma
- Department of Fish and Wildlife Sciences, University of Idaho, College of Natural Resources, Moscow, ID 83844, USA
| | - Shane P. Mahoney
- Conservation Visions Inc., P.O. Box 5489, Station C, 354 Water St., St. John’s, NL A1C 5W4, Canada
| | - Dennis L. Murray
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9J 7B8, Canada
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Abstract
Abstract
Identifying limiting factors is fundamental to understanding and conserving mammals, yet it often requires long-term data for long-lived species. Numerical changes of migratory caribou ( Rangifer tarandus ), for example, may unfold over decades, but few studies have examined habitat use at similar timeframes. We analyzed multiple decades of habitat use by caribou in Newfoundland, Canada, coincident with their numeric growth ( r = 0.064 in 1980s, 1990s) and decline ( r = −0.099 in 2000s). We examined 2 scales: selection of land cover, based on radiotracking of 520 adult females, and diet, based on microhistological analysis of feces and age-specific tooth wear from jawbones of harvested animals. Caribou responded at both scales. In contrast to previous decades, females during the population decline used proportionally less open coniferous and closed coniferous forests, they used more shrublands (in fall and winter) and barrens, open habitats with greater vascular plant resources. Patterns of selection also changed from nonselection to avoidance of open coniferous forest and from avoidance to nonselection or preference of barrens. The proportion of dietary moss increased at the expense of deciduous shrubs, especially during spring and summer and of ericaceous shrubs, graminoids, and lichens during winter. Teeth of both sexes exhibited premature wear, likely indicative of abrasion from low-quality forages and cropping of foods near the ground. These patterns mirror other responses, including declines in calf weight, female body size, number of male antler points, herd affinities, and time spent on the summer grounds. We surmise that they reflect density-dependent forage limitation of this island population.
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Bastille-Rousseau G, Schaefer JA, Lewis KP, Mumma MA, Ellington EH, Rayl ND, Mahoney SP, Pouliot D, Murray DL. Phase-dependent climate-predator interactions explain three decades of variation in neonatal caribou survival. J Anim Ecol 2015; 85:445-56. [DOI: 10.1111/1365-2656.12466] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 10/16/2015] [Indexed: 11/27/2022]
Affiliation(s)
| | - James A. Schaefer
- Environmental and Life Sciences Graduate Program; Trent University; Peterborough Ontario K9J 7B8 Canada
| | - Keith P. Lewis
- Newfoundland and Labrador Department of Environment and Conservation; P.O. Box 8700 St. John's Newfoundland and Labrador A1B 4J6 Canada
| | - Matthew A. Mumma
- Department of Fish and Wildlife Sciences; College of Natural Resources; University of Idaho; Moscow ID 83844 USA
| | - E. Hance Ellington
- Environmental and Life Sciences Graduate Program; Trent University; Peterborough Ontario K9J 7B8 Canada
| | - Nathaniel D. Rayl
- Department of Environmental Conservation; University of Massachusetts; Amherst Massachusetts 01003 USA
| | - Shane P. Mahoney
- Newfoundland and Labrador Department of Environment and Conservation; P.O. Box 8700 St. John's Newfoundland and Labrador A1B 4J6 Canada
| | - Darren Pouliot
- Natural Resources Canada; Canada Centre for Remote Sensing; Ottawa Ontario K1A 0E4 Canada
| | - Dennis L. Murray
- Environmental and Life Sciences Graduate Program; Trent University; Peterborough Ontario K9J 7B8 Canada
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Woodland caribou calf mortality in Newfoundland: insights into the role of climate, predation and population density over three decades of study. POPUL ECOL 2015. [DOI: 10.1007/s10144-015-0525-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Rayl ND, Fuller TK, Organ JF, Mcdonald JE, Otto RD, Bastille-Rousseau G, Soulliere CE, Mahoney SP. Spatiotemporal variation in the distribution of potential predators of a resource pulse: Black bears and caribou calves in Newfoundland. J Wildl Manage 2015. [DOI: 10.1002/jwmg.936] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Nathaniel D. Rayl
- Department of Environmental Conservation; University of Massachusetts; 160 Holdsworth Way Amherst MA 01003 USA
| | - Todd K. Fuller
- Department of Environmental Conservation; University of Massachusetts; 160 Holdsworth Way Amherst MA 01003 USA
| | - John F. Organ
- United States Fish and Wildlife Service; 300 Westgate Center Drive Hadley MA 01035 USA
| | - John E. Mcdonald
- Environmental Science Department; Westfield State University; 214A Wilson Hall Westfield MA 01086 USA
| | - Robert D. Otto
- Department of Environment and Conservation; Institute for Biodiversity, Ecosystem Science, and Sustainability; Government of Newfoundland and Labrador; 117 Riverside Drive, P.O. Box 2007 Corner Brook NL A2H 7S1 Canada
| | - Guillaume Bastille-Rousseau
- Environmental and Life Sciences Graduate Program; Trent University; 1600 West Bank Drive Peterborough ON K9J 7B8 Canada
| | - Colleen E. Soulliere
- Department of Environment and Conservation; Government of Newfoundland and Labrador; Sir Brian Dunfield Bldg #306, P.O. Box 8700, St. John's NL A1B 4J6 Canada
| | - Shane P. Mahoney
- Department of Environment and Conservation; Government of Newfoundland and Labrador; Sir Brian Dunfield Bldg #306, P.O. Box 8700, St. John's NL A1B 4J6 Canada
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Thompson ID, Wiebe PA, Mallon E, Rodgers AR, Fryxell JM, Baker JA, Reid D. Factors influencing the seasonal diet selection by woodland caribou (Rangifer tarandus tarandus) in boreal forests in Ontario. CAN J ZOOL 2015. [DOI: 10.1139/cjz-2014-0140] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We used remote video cameras to assess seasonal diet composition of woodland caribou (Rangifer tarandus tarandus (L., 1758)) at three areas across the boreal forest of Ontario. Caribou consume lichens in winter, but we expected they would significantly reduce lichen consumption in favour of higher protein levels in green plants in summer. We sampled videos from 23 caribou, from 2 years, to derive seasonal diet composition. Diet differed among seasons and study areas, except in winter when lichens dominated. Diet breadth doubled from winter to summer, but overlap between seasons was still >60%. Green plants were less commonly eaten than we expected, only three genera were preferred, and few species constituted more than 2% of the diet. Preferred foods varied by land-cover types. Diet differed between managed and unmanaged landscapes but did not result from use of plant species found in successional habitats. Caribou selected a nonoptimal diet in the snow-free seasons, especially with respect to protein, suggesting factors other than nutrition influenced diet choice, and indicating the possibility of bottom-up limitation on production.
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Affiliation(s)
- Ian D. Thompson
- Great Lakes Forestry Centre, Canadian Forest Service, 1219 Queen Street East, Sault Ste. Marie, ON P6A 2E5, Canada
| | - Philip A. Wiebe
- Great Lakes Forestry Centre, Canadian Forest Service, 1219 Queen Street East, Sault Ste. Marie, ON P6A 2E5, Canada
| | - Erin Mallon
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Arthur R. Rodgers
- Ontario Ministry of Natural Resources, Centre for Northern Forest Ecosystems Research, 955 Oliver Road, Thunder Bay, ON P7B 5E5, Canada
| | - John M. Fryxell
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - James A. Baker
- Ontario Forest Research Institute, Ontario Ministry of Natural Resources, 1235 Queen Street East, Sault Ste. Marie, ON P6A 2E5, Canada
| | - Douglas Reid
- Ontario Ministry of Natural Resources, Centre for Northern Forest Ecosystems Research, 955 Oliver Road, Thunder Bay, ON P7B 5E5, Canada
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Åhman B, Svensson K, Rönnegård L. High female mortality resulting in herd collapse in free-ranging domesticated reindeer (Rangifer tarandus tarandus) in Sweden. PLoS One 2014; 9:e111509. [PMID: 25356591 PMCID: PMC4214728 DOI: 10.1371/journal.pone.0111509] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 10/01/2014] [Indexed: 11/18/2022] Open
Abstract
Reindeer herding in Sweden is a form of pastoralism practised by the indigenous Sámi population. The economy is mainly based on meat production. Herd size is generally regulated by harvest in order not to overuse grazing ranges and keep a productive herd. Nonetheless, herd growth and room for harvest is currently small in many areas. Negative herd growth and low harvest rate were observed in one of two herds in a reindeer herding community in Central Sweden. The herds (A and B) used the same ranges from April until the autumn gathering in October–December, but were separated on different ranges over winter. Analyses of capture-recapture for 723 adult female reindeer over five years (2007–2012) revealed high annual losses (7.1% and 18.4%, for herd A and B respectively). A continuing decline in the total reindeer number in herd B demonstrated an inability to maintain the herd size in spite of a very small harvest. An estimated breakpoint for when herd size cannot be kept stable confirmed that the observed female mortality rate in herd B represented a state of herd collapse. Lower calving success in herd B compared to A indicated differences in winter foraging conditions. However, we found only minor differences in animal body condition between the herds in autumn. We found no evidence that a lower autumn body mass generally increased the risk for a female of dying from one autumn to the next. We conclude that the prime driver of the on-going collapse of herd B is not high animal density or poor body condition. Accidents or disease seem unlikely as major causes of mortality. Predation, primarily by lynx and wolverine, appears to be the most plausible reason for the high female mortality and state of collapse in the studied reindeer herding community.
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Affiliation(s)
- Birgitta Åhman
- Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail:
| | - Kristin Svensson
- School of Technology & Business Studies, Dalarna University, Falun, Sweden
| | - Lars Rönnegård
- School of Technology & Business Studies, Dalarna University, Falun, Sweden
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