Hunting and mountain sheep: Do current harvest practices affect horn growth?

Evolutionary Applications

Anne Hubbs¹  James R. Heffelfinger²  A. Andrew Holland³  Ryan A. Long⁴  Vernon C. Bleich⁵  Kevin L. Monteith⁶  R. Terry Bowyer⁷  Bruce Sterling⁸  Mike Cox⁹  Jonathan D. Muir^1,10  Paul R. Krausman^1,11  Chadwick P. Lehman^1,12  Robert W. Klaver^1,13  Justin M. Shannon^1,14  Clay E. Brewer^1,15  Tayler N. LaSharr^1,16 

[1] Alberta Environment and Parks Rocky Mountain House AB Canada;Arizona Game and Fish Department Phoenix AZ USA;Colorado Parks and Wildlife Fort Collins CO USA;Department of Fish and Wildlife Sciences University of Idaho Moscow ID USA;Department of Natural Resources and Environmental Science University of Nevada Reno Reno NV USA;Haub School of Environment and Natural Resources, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology University of Wyoming Laramie WY USA;Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK USA;Montana Fish, Wildlife, and Parks Thompson Falls MT USA;Nevada Department of Wildlife Reno NV USA;Oregon Department of Fish and Wildlife Lakeview OR USA;School of Natural Resources and the Environment University of Arizona Tucson AZ USA;South Dakota Game Fish and Parks Custer SD USA;US Geological Survey, Iowa Cooperative Fish and Wildlife Research Unit, Department of Natural Resource Ecology and Management Iowa State University Ames IA USA;Utah Division of Wildlife Resources Salt Lake City UT USA;Western Association of Fish and Wildlife Agencies—Wild Sheep Working Group Texas Parks and Wildlife Department Rochelle TX USA;Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology University of Wyoming Laramie WY USA;

关键词: artificial evolution;    bighorn sheep;    harvest‐induced evolution;    horns;    selective harvest;    trophy hunting;   

DOI  :  10.1111/eva.12841

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown