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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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Chen RS, Soulsbury CD, Lebigre C, Ludwig G, van Oers K, Hoffman JI. Effects of hunting on genetic diversity, inbreeding and dispersal in Finnish black grouse (
Lyrurus tetrix
). Evol Appl 2022; 16:625-637. [PMID: 36969146 PMCID: PMC10033861 DOI: 10.1111/eva.13521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 12/06/2022] [Indexed: 12/28/2022] Open
Abstract
Intensive hunting activities such as commercial fishing and trophy hunting can have profound influences on natural populations. However, less intensive recreational hunting can also have subtle effects on animal behaviour, habitat use and movement, with implications for population persistence. Lekking species such as the black grouse (Lyrurus tetrix) may be especially prone to hunting as leks are temporally and spatially predictable, making them easy targets. Furthermore, inbreeding in black grouse is mainly avoided through female-biased dispersal, so any disruptions to dispersal caused by hunting could lead to changes in gene flow, increasing the risk of inbreeding. We therefore investigated the impact of hunting on genetic diversity, inbreeding and dispersal on a metapopulation of black grouse in Central Finland. We genotyped 1065 adult males and 813 adult females from twelve lekking sites (six hunted, six unhunted) and 200 unrelated chicks from seven sites (two hunted, five unhunted) at up to thirteen microsatellite loci. Our initial confirmatory analysis of sex-specific fine-scale population structure revealed little genetic structure in the metapopulation. Levels of inbreeding did not differ significantly between hunted and unhunted sites in neither adults nor chicks. However, immigration rates into hunted sites were significantly higher among adults compared to immigration into unhunted sites. We conclude that the influx of migrants into hunted sites may compensate for the loss of harvested individuals, thereby increasing gene flow and mitigating inbreeding. Given the absence of any obvious barriers to gene flow in Central Finland, a spatially heterogeneous matrix of hunted and unhunted regions may be crucial to ensure sustainable harvests into the future.
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Affiliation(s)
- Rebecca S. Chen
- Department of Animal Behaviour University of Bielefeld Bielefeld Germany
| | - Carl D. Soulsbury
- School of Life and Environmental Sciences, Joseph Banks Laboratories University of Lincoln Lincoln UK
| | - Christophe Lebigre
- UMR DECOD (Ecosystem Dynamics and Sustainability), IFREMER, INRAE Institut Agro Plouzané France
| | - Gilbert Ludwig
- Institute of Bioeconomy JAMK University of Applied Sciences Tarvaala Finland
| | - Kees van Oers
- Department of Animal Ecology Netherlands Institute of Ecology (NIOO‐KNAW) Wageningen The Netherlands
| | - Joseph I. Hoffman
- Department of Animal Behaviour University of Bielefeld Bielefeld Germany
- British Antarctic Survey Cambridge UK
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3
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Schindler S, Ruckstuhl KE, Neuhaus P. Male mating behaviour affects growth of secondary sexual traits: a mechanism for rapid phenotypic change. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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4
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Jackson J, Mar KU, Htut W, Childs DZ, Lummaa V. Changes in age-structure over four decades were a key determinant of population growth rate in a long-lived mammal. J Anim Ecol 2020; 89:2268-2278. [PMID: 32592591 DOI: 10.1111/1365-2656.13290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 06/04/2020] [Indexed: 11/27/2022]
Abstract
A changing environment directly influences birth and mortality rates, and thus population growth rates. However, population growth rates in the short term are also influenced by population age-structure. Despite its importance, the contribution of age-structure to population growth rates has rarely been explored empirically in wildlife populations with long-term demographic data. Here we assessed how changes in age-structure influenced short-term population dynamics in a semi-captive population of Asian elephants Elephas maximus. We addressed this question using a demographic dataset of female Asian elephants from timber camps in Myanmar spanning 45 years (1970-2014). First, we explored temporal variation in age-structure. Then, using annual matrix population models, we used a retrospective approach to assess the contributions of age-structure and vital rates to short-term population growth rates with respect to the average environment. Age-structure was highly variable over the study period, with large proportions of juveniles in the years 1970 and 1985, and made a substantial contribution to annual population growth rate deviations. High adult birth rates between 1970 and 1980 would have resulted in large positive population growth rates, but these were prevented by a low proportion of reproductive-aged females. We highlight that an understanding of both age-specific vital rates and age-structure is needed to assess short-term population dynamics. Furthermore, this example from a human-managed system suggests that the importance of age-structure may be accentuated in populations experiencing human disturbance where age-structure is unstable, such as those in captivity or for endangered species. Ultimately, changes to the environment drive population dynamics by influencing birth and mortality rates, but understanding demographic structure is crucial for assessing population growth.
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Affiliation(s)
- John Jackson
- Department of Biology, Interdisciplinary Centre for Population Dynamics, University of Southern Denmark, Odense M, Denmark.,Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Khyne U Mar
- Department of Biology, University of Turku, Turku, Finland
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Gyogone Forest Compound, Yangon, Myanmar
| | - Dylan Z Childs
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
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5
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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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7
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Kardos M, Luikart G, Allendorf FW. Predicting the evolutionary effects of hunting requires an understanding of genetics. J Wildl Manage 2018. [DOI: 10.1002/jwmg.21475] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Marty Kardos
- University of Montana, Division of Biological Sciences; Flathead Lake Biological Station; 32125 Biostation Lane Polson MT 59860 USA
| | - Gordon Luikart
- University of Montana, Division of Biological Sciences; Flathead Lake Biological Station; 32125 Biostation Lane Polson MT 59860 USA
| | - Fred W. Allendorf
- University of Montana; Division of Biological Sciences; 32 Campus Drive Missoula MT 59812 USA
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8
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Büntgen U, Galván JD, Mysterud A, Krusic PJ, Hülsmann L, Jenny H, Senn J, Bollmann K. Horn growth variation and hunting selection of the Alpine ibex. J Anim Ecol 2018; 87:1069-1079. [DOI: 10.1111/1365-2656.12839] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 03/21/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Ulf Büntgen
- Department of Geography; University of Cambridge; Cambridge UK
- Swiss Federal Research Institute WSL; Birmensdorf Switzerland
- Global Change Research Centre and Masaryk University; Brno Czech Republic
| | - Juan D. Galván
- Swiss Federal Research Institute WSL; Birmensdorf Switzerland
| | - Atle Mysterud
- Centre for Ecological and Evolutionary Synthesis (CEES); Department of Biosciences; University of Oslo; Oslo Norway
| | - Paul J. Krusic
- Department of Geography; University of Cambridge; Cambridge UK
- Department of Physical Geography; Stockholm University; Stockholm Sweden
| | - Lisa Hülsmann
- Swiss Federal Research Institute WSL; Birmensdorf Switzerland
- Forest Ecology; Institute of Terrestrial Ecosystems; Department of Environmental Sciences; ETH Zurich; Zurich Switzerland
- Department of Theoretical Ecology; University of Regensburg; Regensburg Germany
| | - Hannes Jenny
- Department of Wildlife and Fishery Service Grisons; Chur Switzerland
| | - Josef Senn
- Swiss Federal Research Institute WSL; Birmensdorf Switzerland
| | - Kurt Bollmann
- Swiss Federal Research Institute WSL; Birmensdorf Switzerland
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9
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Bischof R, Bonenfant C, Rivrud IM, Zedrosser A, Friebe A, Coulson T, Mysterud A, Swenson JE. Regulated hunting re-shapes the life history of brown bears. Nat Ecol Evol 2017; 2:116-123. [PMID: 29230025 DOI: 10.1038/s41559-017-0400-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/31/2017] [Indexed: 12/24/2022]
Abstract
Management of large carnivores is among the most controversial topics in natural resource administration. Regulated hunting is a centrepiece of many carnivore management programmes and, although a number of hunting effects on population dynamics, body-size distributions and life history in other wildlife have been observed, its effects on life history and demography of large carnivores remain poorly documented. We report results from a 30-year study of brown bears (Ursus arctos) analysed using an integrated hierarchical approach. Our study revealed that regulated hunting has severely disrupted the interplay between age-specific survival and environmental factors, altered the consequences of reproductive strategies, and changed reproductive values and life expectancy in a population of the world's largest terrestrial carnivore. Protection and sustainable management have led to numerical recovery of several populations of large carnivores, but managers and policymakers should be aware of the extent to which regulated hunting may be influencing vital rates, thereby reshaping the life history of apex predators.
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Affiliation(s)
- Richard Bischof
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway.
| | - Christophe Bonenfant
- Université de Lyon, F-69000, CNRS, UMR, 5558, Laboratoire de Biométrie et Biologie Évolutive, Villeurbanne, France
| | - Inger Maren Rivrud
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Andreas Zedrosser
- Department of Natural Sciences and Environmental Health, University College of Southeast Norway, Bø, Norway.,Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Andrea Friebe
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Tim Coulson
- Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK
| | - Atle Mysterud
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jon E Swenson
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway.,Norwegian Institute for Nature Research, Trondheim, Norway
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