Joseph E. Rogerson. Delaware Division of Fish and Wildlife. 6180 Hay Point Landing Road,. Smyrna, DE 19977. Jacob L. Bowman. University of Delaware.
Technical Session Factors Influencing Survival of Yearling Male White-tailed Deer in Delaware Haus, Jacob, M. University of Delaware. 531 South College Avenue, Newark, DE 19716 Joseph E. Rogerson. Delaware Division of Fish and Wildlife. 6180 Hay Point Landing Road, Smyrna, DE 19977 Jacob L. Bowman. University of Delaware. 531 South College Avenue, Newark, DE 19716 ABSTRACT Managing male age structure in white-tailed deer populations is an important objective for state managers and private landowners seeking to improve hunter satisfaction while maintaining appropriate densities. Limiting mortality in the yearling age class is often the primary consideration, and regional differences in habitat, regulations, and hunter behavior complicate our understanding of how specific factors influence survival. We used Cox proportional hazard modeling to examine the effects of distance to road, distance to forest edge, dispersal behaviors, and landownership on the risk of mortality for yearling males (n = 61) in southern Delaware. Annual survival averaged 0.60 (95% CI = 0.49 – 0.73), with hunter harvest accounting for 79% of mortalities. The best approximating model for risk of mortality included covariates for landownership (public/private; P < 0.01) and distance to forest edge (P = 0.01), with mortality risk increasing both on public land and in closer proximity to forest edge. Increased risk of harvest due to forest fragmentation is well documented; however, the effect of landownership has not been quantified, particularly when hunter objectives and behaviors differ between landownership types. We observed annual survival rates of 0.75 (95% CI = 0.62 – 0.89) for deer exclusively on private land during the hunting season, and 0.37 (95% CI = 0.18 – 0.73) for deer that utilized public land during the hunting season. Survival rates on private land were
comparable to research performed on properties that actively manage male age structure, but harvest of yearlings limited age structure on public land within the study area.
