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Lassis R, Festa‐Bianchet M, Van de Walle J, Pelletier F. Genetic rescue from protected areas is modulated by migration, hunting rate, and timing of harvest. Evol Appl 2023; 16:1105-1118. [PMID: 37360026 PMCID: PMC10286230 DOI: 10.1111/eva.13554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 04/17/2023] [Accepted: 04/20/2023] [Indexed: 06/28/2023] Open
Abstract
In terrestrial and marine ecosystems, migrants from protected areas may buffer the risk of harvest-induced evolutionary changes in exploited populations that face strong selective harvest pressures. Understanding the mechanisms favoring genetic rescue through migration could help ensure evolutionarily sustainable harvest outside protected areas and conserve genetic diversity inside those areas. We developed a stochastic individual-based metapopulation model to evaluate the potential for migration from protected areas to mitigate the evolutionary consequences of selective harvest. We parameterized the model with detailed data from individual monitoring of two populations of bighorn sheep subjected to trophy hunting. We tracked horn length through time in a large protected and a trophy-hunted populations connected through male breeding migrations. We quantified and compared declines in horn length and rescue potential under various combinations of migration rate, hunting rate in hunted areas and temporal overlap in timing of harvest and migrations, which affects the migrants' survival and chances to breed within exploited areas. Our simulations suggest that the effects of size-selective harvest on male horn length in hunted populations can be dampened or avoided if harvest pressure is low, migration rate is substantial, and migrants leaving protected areas have a low risk of being shot. Intense size-selective harvest impacts the phenotypic and genetic diversity in horn length, and population structure through changes in proportions of large-horned males, sex ratio and age structure. When hunting pressure is high and overlaps with male migrations, effects of selective removal also emerge in the protected population, so that instead of a genetic rescue of hunted populations, our model predicts undesirable effects inside protected areas. Our results stress the importance of a landscape approach to management, to promote genetic rescue from protected areas and limit ecological and evolutionary impacts of harvest on both harvested and protected populations.
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Affiliation(s)
- Roxane Lassis
- Département de biologie et Centre d'Études NordiquesUniversité de SherbrookeSherbrookeQuebecCanada
| | - Marco Festa‐Bianchet
- Département de biologie et Centre d'Études NordiquesUniversité de SherbrookeSherbrookeQuebecCanada
| | - Joanie Van de Walle
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Fanie Pelletier
- Département de biologie et Centre d'Études NordiquesUniversité de SherbrookeSherbrookeQuebecCanada
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2
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Martin H, Hebblewhite M, Hubbs A, Corrigan R, Merrill EH. Male elk survival, vulnerability, and antler size in a transboundary and partially migratory population. J Wildl Manage 2023. [DOI: 10.1002/jwmg.22386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Affiliation(s)
- Hans Martin
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation University of Montana Missoula MT 59812 USA
| | - Mark Hebblewhite
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation University of Montana Missoula MT 59812 USA
| | - Anne Hubbs
- Alberta Environment and Parks Box 1720, 4919‐51 Street, Provincial Building Rocky Mountain House AB T4T 1B3 Canada
| | - Rob Corrigan
- Alberta Environment and Parks 9920 108 Street Edmonton AB T5K 2M4 Canada
| | - Evelyn H. Merrill
- Department of Biological Sciences University of Alberta Edmonton AB T1L 16K Canada
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3
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Sørdalen TK, Halvorsen KT, Olsen EM. Protection from fishing improves body growth of an exploited species. Proc Biol Sci 2022; 289:20221718. [DOI: 10.1098/rspb.2022.1718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Hunting and fishing are often size-selective, which favours slow body growth. In addition, fast growth rate has been shown to be positively correlated with behavioural traits that increase encounter rates and catchability in passive fishing gears such as baited traps. This harvest-induced selection should be effectively eliminated in no-take marine-protected areas (MPAs) unless strong density dependence results in reduced growth rates. We compared body growth of European lobster (
Homarus gammarus
) between three MPAs and three fished areas. After 14 years of protection from intensive, size-selective lobster fisheries, the densities in MPAs have increased considerably, and we demonstrate that females moult more frequently and grow more during each moult in the MPAs. A similar, but weaker pattern was evident for males. This study suggests that MPAs can shield a wild population from slow-growth selection, which can explain the rapid recovery of size structure following implementation. If slow-growth selection is a widespread phenomenon in fisheries, the effectiveness of MPAs as a management tool can be higher than currently anticipated.
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Affiliation(s)
- Tonje Knutsen Sørdalen
- Centre for Coastal Research, Department of Natural Sciences, University of Agder, N-4604 Kristiansand, Norway
- Institute of Marine Research, Flødevigen, Nye Flødevigvei 20, N-4817 His, Norway
| | | | - Esben Moland Olsen
- Centre for Coastal Research, Department of Natural Sciences, University of Agder, N-4604 Kristiansand, Norway
- Institute of Marine Research, Flødevigen, Nye Flødevigvei 20, N-4817 His, Norway
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4
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Lassis R, Festa-Bianchet M, Pelletier F. Effects of hunting pressure and timing of harvest on bighorn sheep horn size. CAN J ZOOL 2022. [DOI: 10.1139/cjz-2021-0082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Trophy hunting can affect weapon size of wild animals through both demographic and evolutionary changes. In bighorn sheep (Ovis canadensis Shaw, 1804), intense harvest of young males with fast-growing horns may have partly driven long-term decreases in horn size. These selective effects could be dampened if migrants from protected areas, not subject to artificial selection, survived and reproduced within hunted populations. Bighorn rams undertake long-distance breeding migrations in the weeks preceding the late-November rut. We analysed records of >7 800 trophy bighorn rams shot from 1974 to 2019 in Alberta, Canada, to test the hypothesis that high harvest pressure during breeding migrations was correlated with a greater decrease in horn size. We compared areas with and without a pronounced harvest peak in late October, when male breeding migrations begin. Areas without a pronounced harvest peak in late October, that likely experienced a lower harvest rate, showed a similar temporal decline in horn size, but no increase in age at harvest suggesting a possibly weaker decline in horn growth. Our study suggests that unselected immigrants from protected areas could partly buffer the effects of intense trophy hunting only if harvest pressure was reduced when breeding migrations commence.
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Affiliation(s)
- Roxane Lassis
- Université de Sherbrooke, 7321, Sherbrooke, Quebec, Canada
| | - Marco Festa-Bianchet
- Universite de Sherbrooke, 7321, Département de biologie, Sherbrooke, Quebec, Canada
| | - Fanie Pelletier
- Université de Sherbrooke, Biologie, Sherbrooke, Quebec, Canada
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5
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Lassis R, Festa‐Bianchet M, Pelletier F. Breeding migrations by bighorn sheep males are driven by mating opportunities. Ecol Evol 2022; 12:e8692. [PMID: 35342589 PMCID: PMC8928905 DOI: 10.1002/ece3.8692] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 02/08/2022] [Accepted: 02/14/2022] [Indexed: 11/16/2022] Open
Abstract
In some species where male mating success largely depends on intrasexual competition, males can adopt migratory or resident strategies to seek breeding opportunities. The resulting mixture of resident and migrant tactics within a population can have important ecological, genetic, and evolutionary consequences for metapopulations. Bighorn sheep Ovis canadensis males establish a linear dominance hierarchy that influences their mating tactics. Some males perform breeding migrations during the pre-rut and rut to seek mating opportunities, but little is known about these seasonal movements. We analyzed presence/absence data for 62 marked bighorn males during six mating seasons (20-32 males/year) in the Sheep River Provincial Park, Alberta, Canada, where hunting was not allowed. On average, about half of males left their natal population to rut elsewhere. The proportion of males leaving (yearly range 15%-69%) increased as the number of resident mature males increased and the populational sex ratio decreased, with fewer females during the pre-rut. Among those leaving the park, 24% did so in October, while the trophy sheep hunting season was open. Detailed monitoring of breeding migrations in protected populations could inform management strategies to limit evolutionary impacts of hunting, which can alter size-dependent mortality and create artificial pressures driving changes on heritable traits.
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Affiliation(s)
- Roxane Lassis
- Département de biologie et Centre d’Études NordiquesUniversité de SherbrookeSherbrookeQuebecCanada
| | - Marco Festa‐Bianchet
- Département de biologie et Centre d’Études NordiquesUniversité de SherbrookeSherbrookeQuebecCanada
| | - Fanie Pelletier
- Département de biologie et Centre d’Études NordiquesUniversité de SherbrookeSherbrookeQuebecCanada
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6
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Sørdalen TK, Halvorsen KT, Vøllestad LA, Moland E, Olsen EM. Marine protected areas rescue a sexually selected trait in European lobster. Evol Appl 2020; 13:2222-2233. [PMID: 33005220 PMCID: PMC7513721 DOI: 10.1111/eva.12992] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/16/2020] [Accepted: 04/23/2020] [Indexed: 11/29/2022] Open
Abstract
Marine protected areas (MPAs) are increasingly implemented worldwide to maintain and restore depleted populations. However, despite our knowledge on the myriad of positive responses to protection, there are few empirical studies on the ability to conserve species' mating patterns and secondary sexual traits. In male European lobsters (Homarus gammarus), the size of claws relative to body size correlates positively with male mating success and is presumably under sexual selection. At the same time, an intensive trap fishery exerts selection against large claws in males. MPAs could therefore be expected to resolve these conflicting selective pressures and preserve males with large claws. We explored this hypothesis by contrasting claw size of males and females in three pairs of MPAs and nearby fished areas in southern Norway. By finding that male lobsters have up to 8% larger claws inside MPAs compared to similarly sized males in fished areas, our study provides evidence that MPAs rescue a secondary sexual trait. Recovery from harvest selection acting on claws is the most likely explanation; however, the higher abundance of lobster inside MPAs does not rule out a plastic response on claw size due to increased competition. Regardless of the underlying cause, our study demonstrates (a) the value of protected areas as a management tool for mitigating fisheries-induced evolution and (b) that MPAs help maintaining the scope for sexual selection in populations with vulnerable life histories and complex mating system.
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Affiliation(s)
- Tonje Knutsen Sørdalen
- Department of Natural Sciences Centre for Coastal Research University of Agder Kristiansand Norway
- Institute of Marine Research Flødevigen Norway
| | | | - Leif Asbjørn Vøllestad
- Department of Biosciences Centre for Ecological and Evolutionary Synthesis (CEES) University of Oslo Oslo Norway
| | - Even Moland
- Department of Natural Sciences Centre for Coastal Research University of Agder Kristiansand Norway
- Institute of Marine Research Flødevigen Norway
| | - Esben Moland Olsen
- Department of Natural Sciences Centre for Coastal Research University of Agder Kristiansand Norway
- Institute of Marine Research Flødevigen Norway
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7
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Poisson Y, Festa‐Bianchet M, Pelletier F. Testing the importance of harvest refuges for phenotypic rescue of trophy‐hunted populations. J Appl Ecol 2020. [DOI: 10.1111/1365-2664.13562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yoanna Poisson
- Département de biologie Université de Sherbrooke Sherbrooke QC Canada
| | | | - Fanie Pelletier
- Département de biologie Université de Sherbrooke Sherbrooke QC Canada
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8
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LaSharr TN, Long RA, Heffelfinger JR, Bleich VC, Krausman PR, Bowyer RT, Shannon JM, Klaver RW, Brewer CE, Cox M, Holland AA, Hubbs A, Lehman CP, Muir JD, Sterling B, Monteith KL. Hunting and mountain sheep: Do current harvest practices affect horn growth? Evol Appl 2019; 12:1823-1836. [PMID: 31548860 PMCID: PMC6752155 DOI: 10.1111/eva.12841] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 07/04/2019] [Accepted: 07/06/2019] [Indexed: 11/27/2022] Open
Abstract
The influence of human harvest on evolution of secondary sexual characteristics has implications for sustainable management of wildlife populations. The phenotypic consequences of selectively removing males with large horns or antlers from ungulate populations have been a topic of heightened concern in recent years. Harvest can affect size of horn-like structures in two ways: (a) shifting age structure toward younger age classes, which can reduce the mean size of horn-like structures, or (b) selecting against genes that produce large, fast-growing males. We evaluated effects of age, climatic and forage conditions, and metrics of harvest on horn size and growth of mountain sheep (Ovis canadensis ssp.) in 72 hunt areas across North America from 1981 to 2016. In 50% of hunt areas, changes in mean horn size during the study period were related to changes in age structure of harvested sheep. Environmental conditions explained directional changes in horn growth in 28% of hunt areas, 7% of which did not exhibit change before accounting for effects of the environment. After accounting for age and environment, horn size of mountain sheep was stable or increasing in the majority (~78%) of hunt areas. Age-specific horn size declined in 44% of hunt areas where harvest was regulated solely by morphological criteria, which supports the notion that harvest practices that are simultaneously selective and intensive might lead to changes in horn growth. Nevertheless, phenotypic consequences are not a foregone conclusion in the face of selective harvest; over half of the hunt areas with highly selective and intensive harvest did not exhibit age-specific declines in horn size. Our results demonstrate that while harvest regimes are an important consideration, horn growth of harvested male mountain sheep has remained largely stable, indicating that changes in horn growth patterns are an unlikely consequence of harvest across most of North America.
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Affiliation(s)
- Tayler N. LaSharr
- Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and PhysiologyUniversity of WyomingLaramieWYUSA
| | - Ryan A. Long
- Department of Fish and Wildlife SciencesUniversity of IdahoMoscowIDUSA
| | | | - Vernon C. Bleich
- Department of Natural Resources and Environmental ScienceUniversity of Nevada RenoRenoNVUSA
| | - Paul R. Krausman
- School of Natural Resources and the EnvironmentUniversity of ArizonaTucsonAZUSA
| | - R. Terry Bowyer
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAKUSA
| | | | - Robert W. Klaver
- US Geological Survey, Iowa Cooperative Fish and Wildlife Research Unit, Department of Natural Resource Ecology and ManagementIowa State UniversityAmesIAUSA
| | - Clay E. Brewer
- Western Association of Fish and Wildlife Agencies—Wild Sheep Working GroupTexas Parks and Wildlife DepartmentRochelleTXUSA
| | - Mike Cox
- Nevada Department of WildlifeRenoNVUSA
| | | | - Anne Hubbs
- Alberta Environment and ParksRocky Mountain HouseABCanada
| | | | | | | | - Kevin L. Monteith
- Haub School of Environment and Natural Resources, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and PhysiologyUniversity of WyomingLaramieWYUSA
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9
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Mountain sheep management using data versus opinions: A comment on Boyce and Krausman (2018). J Wildl Manage 2019. [DOI: 10.1002/jwmg.21542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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10
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11
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Kuparinen A, Festa-Bianchet M. Harvest-induced evolution: insights from aquatic and terrestrial systems. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0036. [PMID: 27920381 DOI: 10.1098/rstb.2016.0036] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2016] [Indexed: 12/29/2022] Open
Abstract
Commercial and recreational harvests create selection pressures for fitness-related phenotypic traits that are partly under genetic control. Consequently, harvesting can drive evolution in targeted traits. However, the quantification of harvest-induced evolutionary life history and phenotypic changes is challenging, because both density-dependent feedback and environmental changes may also affect these changes through phenotypic plasticity. Here, we synthesize current knowledge and uncertainties on six key points: (i) whether or not harvest-induced evolution is happening, (ii) whether or not it is beneficial, (iii) how it shapes biological systems, (iv) how it could be avoided, (v) its importance relative to other drivers of phenotypic changes, and (vi) whether or not it should be explicitly accounted for in management. We do this by reviewing findings from aquatic systems exposed to fishing and terrestrial systems targeted by hunting. Evidence from aquatic systems emphasizes evolutionary effects on age and size at maturity, while in terrestrial systems changes are seen in weapon size and date of parturition. We suggest that while harvest-induced evolution is likely to occur and negatively affect populations, the rate of evolutionary changes and their ecological implications can be managed efficiently by simply reducing harvest intensity.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'.
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Affiliation(s)
- Anna Kuparinen
- Department of Environmental Sciences, University of Helsinki, PO Box 65, 00014 Helsinki, Finland
| | - Marco Festa-Bianchet
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
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12
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Boyce MS, Krausman PR. Special section: Controversies in mountain sheep management. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21400] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Heffelfinger JR. Inefficiency of evolutionarily relevant selection in ungulate trophy hunting. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21337] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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14
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Schindler S, Festa-Bianchet M, Hogg JT, Pelletier F. Hunting, age structure, and horn size distribution in bighorn sheep. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21259] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Susanne Schindler
- University of Zurich; Department of Evolutionary Biology and Environmental Studies; Winterthurer Str. 190 8057 Zurich Switzerland
| | - Marco Festa-Bianchet
- Université de Sherbrooke; Departement de biologie; 2500 boulevard de l'Université Sherbrooke QC J1K 2R1 Canada
| | - John T. Hogg
- Montana Conservation Science Institute; 5200 Upper Miller Creek Road Missoula MT 59803 USA
| | - Fanie Pelletier
- Université de Sherbrooke; Departement de biologie; 2500 boulevard de l'Université Sherbrooke QC J1K 2R1 Canada
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15
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Douhard M, Pigeon G, Festa-Bianchet M, Coltman DW, Guillemette S, Pelletier F. Environmental and evolutionary effects on horn growth of male bighorn sheep. OIKOS 2017. [DOI: 10.1111/oik.03799] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Mathieu Douhard
- Dépt de biologie et Centre d’Études Nordiques; Univ. de Sherbrooke, Sherbrooke, QC; J1K 2R1 Canada
| | - Gabriel Pigeon
- Dépt de biologie et Centre d’Études Nordiques; Univ. de Sherbrooke, Sherbrooke, QC; J1K 2R1 Canada
| | - Marco Festa-Bianchet
- Dépt de biologie et Centre d’Études Nordiques; Univ. de Sherbrooke, Sherbrooke, QC; J1K 2R1 Canada
| | - David W. Coltman
- Dépt de biologie et Centre d’Études Nordiques; Univ. de Sherbrooke, Sherbrooke, QC; J1K 2R1 Canada
- Dept of Biological Sciences; Univ. of Alberta, Edmonton; AB, T6G 2E9 Canada
| | - Simon Guillemette
- Dépt de biologie et Centre d’Études Nordiques; Univ. de Sherbrooke, Sherbrooke, QC; J1K 2R1 Canada
| | - Fanie Pelletier
- Dépt de biologie et Centre d’Études Nordiques; Univ. de Sherbrooke, Sherbrooke, QC; J1K 2R1 Canada
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16
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Festa‐Bianchet M. When does selective hunting select, how can we tell, and what should we do about it? Mamm Rev 2016. [DOI: 10.1111/mam.12078] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Marco Festa‐Bianchet
- Département de biologie Université de Sherbrooke Sherbrooke Québec J1K 2R1 Canada
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17
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Douhard M, Festa-Bianchet M, Pelletier F, Gaillard JM, Bonenfanti C. Changes in horn size of Stone's sheep over four decades correlate with trophy hunting pressure. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:309-321. [PMID: 27039527 DOI: 10.1890/14-1461] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Selective harvest may lead to rapid evolutionary change. For large herbivores, trophy hunting removes males with large horns. That artificial selection, operating in opposition to sexual selection, can lead to undesirable consequences for management and conservation. There have been no comparisons of long-term changes in trophy size under contrasting harvest pressures. We analyzed horn measurements of Stone's rams (Ovis dalli stonei) harvested over 37 years in two large regions of British Columbia, Canada, with marked differences in hunting pressure to identify when selective hunting may cause a long-term decrease in horn growth. Under strong selective harvest, horn growth early in life and the number of males harvested declined by 12% and 45%, respectively, over the study period. Horn shape also changed over time: horn length became shorter for a given base circumference, likely because horn base is not a direct target of hunter selection. In contrast, under relatively lower hunting pressure, there were no detectable temporal trends in early horn growth, number of males harvested, or horn length relative to base circumference. Trophy hunting is an important recreational activity and can generate substantial revenues for conservation. By providing a reproductive advantage to males with smaller horns and reducing the availability of desirable trophies, however, excessive harvest may have the undesirable long-term consequences of reducing both the harvest and the horn size of rams. These consequences can be avoided by limiting offtake.
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18
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Festa-Bianchet M, Schindler S, Pelletier F. Record books do not capture population trends in horn length of bighorn sheep. WILDLIFE SOC B 2015. [DOI: 10.1002/wsb.597] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
| | - Susanne Schindler
- Department of Zoology; University of Oxford; Oxford OX1 3PS England United Kingdom
| | - Fanie Pelletier
- Département de biologie; Université de Sherbrooke; Sherbrooke QC J1K 2R1 Canada
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