9th International Deer Biology Congress

AUTHORS: Rebecca M. Shuman, Warnell School of Forestry and Natural Resources, University of Georgia and Division of Hunting and Game Management, Florida Fish and Wildlife Conservation Commission; Michael J. Cherry*, Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University; Taylor N. Simoneaux, Warnell School of Forestry and Natural Resources, University of Georgia; Elizabeth A. Dutoit, Warnell School of Forestry and Natural Resources, University of Georgia; John C. Kilgo, USDA Forest Service, Southern Research Station; Michael J. Chamberlain, Warnell School of Forestry and Natural Resources, University of Georgia; Karl V. Miller, Warnell School of Forestry and Natural Resources, University of Georgia

ABSTRACT: Efforts to recover large carnivores are ubiquitous across the globe; however, the effects of restoration efforts on prey species are often overlooked. Restoration of large carnivores may contribute to decreased survival rates, and managers are interested in the long-term effect of restoration efforts on the sustainability of prey populations. Therefore, we analyzed the population dynamics of white-tailed deer (Odocoileus virginianus) on Tensas River National Wildlife Refuge, Louisiana, USA (TRNWR) following the recovery of the Louisiana black bear (Ursus americanus luteolus). During 2013-15, we radiocollared and monitored 70 neonates as well as 21 yearling (1.5 year-old) and 70 mature (≥2.5 years) female deer. Survival to 12 weeks was 0.271 (95% CI = 0.185-0.398), and black bear predation was the most frequent cause of mortality, accounting for 33% of all mortalities (n = 17). Annual survival averaged 0.857 (95% CI = 0.720-1.00) for yearling females and 0.815 (95% CI = 0.734-0.904) for mature females. Using observed values of neonate survival, female survival, and fecundity data from TRNWR, we estimated the current population trajectory and projected the population for 10 years using various potential harvest intensity scenarios and neonate survival estimates. Under the current vital rates, we estimated an increasing population trajectory (λ = 1.043). Projections for 0% (λ = 1.126) and 10% hunting mortality (λ = 1.041) predicted increasing populations, whereas 20% (λ = 0.959) and 30% hunting mortality (λ = 0.878) resulted in population declines. Reductions in neonate survival led to population declines (λ = 0.950), but elimination of female harvest offset declines (λ = 1.037). Our results indicate that the restoration of large carnivores is not always a harbinger of deer population decline. In herds with high fecundity rates, reduction in survival due to increased predation may not necessitate changes in management strategies, but if low survival rates lead to declining population trajectories, reduced harvest of adult females may be sufficient to reverse these declines.