9th International Deer Biology Congress

AUTHORS: Jacob M. Haus, Department of Entomology and Wildlife Ecology, University of Delaware; Joseph E. Rogerson, Delaware Division of Fish and Wildlife; Justin R. Dion, Jacob L. Bowman – Department of Entomology and Wildlife Ecology, University of Delaware

ABSTRACT: The management of age structure and sex ratios in white-tailed deer populations are important objectives for biologists and state managers seeking to improve hunter satisfaction while maintaining appropriate deer densities. The management of public versus private lands is complicated by differences in hunter densities [1], management philosophies [2], and habitat quality. The impact on rates of harvest mortality among different age and sex classes are poorly understood, particularly when harvest regulations do not differ between landownership types. We monitored cause-specific mortality in 66 fawns (~6 months old), 72 subadult males (1 – 2 years old), 57 adult females (≥ 2 years old), and 33 adult males during the hunting season (1 September – 31 January) from 2015 – 2017 in Sussex County, Delaware, USA (Fig. 1). Non-harvest related mortalities (n = 8) and collar failures (n = 12) were right censored from analysis. Overall, rates of harvest related mortality were relatively low in fawns (0.08; SE = 0.03) and adult females (0.07; SE = 0.03), but greater in subadult males (0.36; SE = 0.06) and adult males (0.40; SE = 0.08). We tested for differences in rates of harvest mortality among deer that were exclusively on private land and for deer that utilized public land during the hunting season using a log-rank test. We did not find any difference in rates of harvest between public and private land in fawns, adult females, or adult males. The harvest rates for subadult males however, was greater (P < 0.01) for deer that utilized public land (0.73; SE = 0.08) than for deer that only utilized private land (0.20; SE = 0.06). We observed low rates of harvest for antlerless deer on both public and private lands. Overall rate of harvest was greater in adult males than subadult males, but hunters on public land appeared to select for males regardless of age, while private land hunters restricted harvest primarily to adult males. Rates of harvest mortality among subadult males on private land were comparable to research from properties that actively manage male age structure [3,4], but harvest on public land was similar to research from areas lacking such management [5] and likely limited male age structure within the study area.