Coyotes (Canis latrans) are a relatively new predator to the southeastern United States, and may be negatively impacting white-tailed deer (Odocoileus virginianus;hereafter, deer) populations. Our objectives were to e...Coyotes (Canis latrans) are a relatively new predator to the southeastern United States, and may be negatively impacting white-tailed deer (Odocoileus virginianus;hereafter, deer) populations. Our objectives were to evaluate the impacts of coyotes on deer fawns by assessing deer fawn survival and cause-specific mortality, and gain an understanding of factors affecting fawn survival and coyote predation. We captured and radio collared 30 fawns in the Red Hills region of Florida and Georgia, USA (2012-2013). Fawns were monitored for 12 weeks for survival and cause-specific mortality, and we quantified habitat and environmental characteristics of birth sites. Predation (n = 19;95%) was the leading cause of fawn mortality (n = 20;67%), with coyote predation (n = 14;74%) being the most important type of predation. Survival rates for all fawns were greater (P = 0.048) where coyotes were removed compared to non-removal sites, with 50% and 25% of fawns surviving to 12 weeks on coyote-removal and non-removal sites, respectively. Survival rates of fawns ultimately predated by coyotes were greater (P = 0.096) on coyote-removal than non-removal sites, with 40% and 50% of fawns predated by coyotes within 12 weeks on coyote-removal and non-removal sites, respectively. Survival of all fawns and those predated by coyotes was lower when fawns were born at sites with greater hardwood basal area, total basal area, and canopy closure;and survival improved if born in or near hardwood, natural pine, and managed (planted) pine cover types. Increased canopy cover within 10 m of the birth site was selected by adult females for birth sites of all fawns and those that were predated by coyotes. Compared with fawns that lived, all dying fawns and those predated by coyotes had less shrub cover within 5 m and less grass cover at and within 10 m of the birth site. Coyote removal increased fawn daily survival rates, and habitat played a role in fawn survival.展开更多
Minerals are critical in maintaining health and physiological function in wildlife. Geographic variation in soil and forage mineral concentration may predispose wildlife to mineral imbalances, where a common symptom i...Minerals are critical in maintaining health and physiological function in wildlife. Geographic variation in soil and forage mineral concentration may predispose wildlife to mineral imbalances, where a common symptom is restricted somatic growth. We investigated if mineral imbalances could explain localized differences in morphology of white-tailed deer (Odocoileus virginianus) occurring in geographically proximate sites with similar management, climate, and habitat. We collected serum samples and morphological measurements from free-ranging white-tailed deer captured during 2011-2019 from coastal and inland rangeland sites in South Texas, USA. We measured mineral concentrations in serum from captured deer at each location. Asymptotic deer body mass and antler size averaged 8% - 20% smaller for deer at the coastal compared to the inland site. The proportion of deer with deficient levels of serum copper was greater at the coastal site (66% versus 14%). Our results suggest regional mineral deficiencies in deer may limit antler and body development. Wildlife managers should be aware of all aspects of wildlife nutrition and the importance of considering nutrients beyond energy and protein.展开更多
In eastern North America, white-tailed deer(Odocoileus virginianus) can have profound influences on forest biodiversity and forest successional processes.Moderate to high deer populations in the central Appalachians h...In eastern North America, white-tailed deer(Odocoileus virginianus) can have profound influences on forest biodiversity and forest successional processes.Moderate to high deer populations in the central Appalachians have resulted in lower forest biodiversity.Legacy effects in some areas persist even following deer population reductions or declines. This has prompted managers to consider deer population management goals in light of policies designed to support conservation of biodiversity and forest regeneration while continuing to support ample recreational hunting opportunities. However,despite known relationships between herbivory intensity and biodiversity impact, little information exists on the predictability of herbivory intensity across the varied and spatially diverse habitat conditions of the central Appalachians. We examined the predictability of browsing rates across central Appalachian landscapes at four environmental scales: vegetative community characteristics, physical environment, habitat configuration, and local human and deer population demographics. In an information-theoretic approach, we found that a model fitting the number of stems browsed relative to local vegetation characteristics received most(62%) of the overall support of all tested models assessing herbivory impact. Our data suggest that deer herbivory responded most predictably to differences in vegetation quantity and type. No other spatial factors or demographic factors consistently affected browsing intensity. Because herbivory, vegetation communities, and productivity vary spatially, we suggest that effective broad-scale herbivory impact assessment should include spatially-balanced vegetation monitoring that accounts for regional differences in deer forage preference.Effective monitoring is necessary to avoid biodiversity impacts and deleterious changes in vegetation community composition that are difficult to reverse and/or may not be detected using traditional deer-density based management goals.展开更多
文摘Coyotes (Canis latrans) are a relatively new predator to the southeastern United States, and may be negatively impacting white-tailed deer (Odocoileus virginianus;hereafter, deer) populations. Our objectives were to evaluate the impacts of coyotes on deer fawns by assessing deer fawn survival and cause-specific mortality, and gain an understanding of factors affecting fawn survival and coyote predation. We captured and radio collared 30 fawns in the Red Hills region of Florida and Georgia, USA (2012-2013). Fawns were monitored for 12 weeks for survival and cause-specific mortality, and we quantified habitat and environmental characteristics of birth sites. Predation (n = 19;95%) was the leading cause of fawn mortality (n = 20;67%), with coyote predation (n = 14;74%) being the most important type of predation. Survival rates for all fawns were greater (P = 0.048) where coyotes were removed compared to non-removal sites, with 50% and 25% of fawns surviving to 12 weeks on coyote-removal and non-removal sites, respectively. Survival rates of fawns ultimately predated by coyotes were greater (P = 0.096) on coyote-removal than non-removal sites, with 40% and 50% of fawns predated by coyotes within 12 weeks on coyote-removal and non-removal sites, respectively. Survival of all fawns and those predated by coyotes was lower when fawns were born at sites with greater hardwood basal area, total basal area, and canopy closure;and survival improved if born in or near hardwood, natural pine, and managed (planted) pine cover types. Increased canopy cover within 10 m of the birth site was selected by adult females for birth sites of all fawns and those that were predated by coyotes. Compared with fawns that lived, all dying fawns and those predated by coyotes had less shrub cover within 5 m and less grass cover at and within 10 m of the birth site. Coyote removal increased fawn daily survival rates, and habitat played a role in fawn survival.
文摘Minerals are critical in maintaining health and physiological function in wildlife. Geographic variation in soil and forage mineral concentration may predispose wildlife to mineral imbalances, where a common symptom is restricted somatic growth. We investigated if mineral imbalances could explain localized differences in morphology of white-tailed deer (Odocoileus virginianus) occurring in geographically proximate sites with similar management, climate, and habitat. We collected serum samples and morphological measurements from free-ranging white-tailed deer captured during 2011-2019 from coastal and inland rangeland sites in South Texas, USA. We measured mineral concentrations in serum from captured deer at each location. Asymptotic deer body mass and antler size averaged 8% - 20% smaller for deer at the coastal compared to the inland site. The proportion of deer with deficient levels of serum copper was greater at the coastal site (66% versus 14%). Our results suggest regional mineral deficiencies in deer may limit antler and body development. Wildlife managers should be aware of all aspects of wildlife nutrition and the importance of considering nutrients beyond energy and protein.
基金financially supported by the Wildlife and Sport Fish Restoration Program,Project WE99,Contract 2012-13694 to Virginia Tech
文摘In eastern North America, white-tailed deer(Odocoileus virginianus) can have profound influences on forest biodiversity and forest successional processes.Moderate to high deer populations in the central Appalachians have resulted in lower forest biodiversity.Legacy effects in some areas persist even following deer population reductions or declines. This has prompted managers to consider deer population management goals in light of policies designed to support conservation of biodiversity and forest regeneration while continuing to support ample recreational hunting opportunities. However,despite known relationships between herbivory intensity and biodiversity impact, little information exists on the predictability of herbivory intensity across the varied and spatially diverse habitat conditions of the central Appalachians. We examined the predictability of browsing rates across central Appalachian landscapes at four environmental scales: vegetative community characteristics, physical environment, habitat configuration, and local human and deer population demographics. In an information-theoretic approach, we found that a model fitting the number of stems browsed relative to local vegetation characteristics received most(62%) of the overall support of all tested models assessing herbivory impact. Our data suggest that deer herbivory responded most predictably to differences in vegetation quantity and type. No other spatial factors or demographic factors consistently affected browsing intensity. Because herbivory, vegetation communities, and productivity vary spatially, we suggest that effective broad-scale herbivory impact assessment should include spatially-balanced vegetation monitoring that accounts for regional differences in deer forage preference.Effective monitoring is necessary to avoid biodiversity impacts and deleterious changes in vegetation community composition that are difficult to reverse and/or may not be detected using traditional deer-density based management goals.
