Affiliation: | 1. University of Montana, W. A. Franke College of Forestry and Conservation, Wildlife Biology Program, 32 Campus Drive, Missoula, MT, 59812 USA E-mail: chloe.wright@ubc.ca Current Address: The University of British Columbia, Department of Biology, 1177 Research Road, Kelowna, BC V1V 1V7, Canada;2. University of Missouri, Department of Fisheries and Wildlife Sciences, 302 Anheuser-Busch Natural Resources Building, Columbia, MO, 65211 USA;3. Missouri Department of Conservation, Resource Science Division, 3500 East Gans Road, Columbia, MO, 65201 USA;4. Missouri Department of Conservation, Resource Science Division, 3500 East Gans Road, Columbia, MO, 65201 USA Current Address: Minnesota Department of Natural Resources, 500 Lafayette Road, St. Paul, MN 55155, USA;5. University of Montana, W. A. Franke College of Forestry and Conservation, Wildlife Biology Program, 32 Campus Drive, Missoula, MT, 59812 USA |
Abstract: | Landscape-level habitat characteristics affect neonatal white-tailed deer (Odocoileus virginianus) survival. Little is known, however, about how changes in maternal habitat use after parturition affect neonate survival. We quantified survival rates and determined if neonate survival to 8 weeks was affected by weekly maternal habitat use in the agricultural Glaciated Plains (GP) and forest-grassland Ozark (OZ) eco-regions of Missouri, USA. We captured 127 pregnant female deer during 2015–2017, and fitted each with a global positioning system (GPS) radio-collar and vaginal implant transmitter (VIT). We captured 226 neonatal deer during 2015–2017, fitted each with an expandable radio-collar, and monitored survival status daily. We estimated weekly maternal home ranges and calculated habitat metrics within these home ranges. We used the Kaplan-Meier estimator to calculate 8-week survival estimates and Cox proportional hazards models to investigate the influence of habitat metrics on neonate survival. The 8-week survival estimates were 0.43 (95% CI = 0.35–0.54) and 0.47 (95% CI = 0.38–0.57) in the GP and OZ, respectively. Both of these survival estimates were lower than expected but particularly so in the GP because it is dominated by agricultural fields, a land cover type typically associated with high survival. Neonate survival in the GP was negatively correlated with the amount of edge and forest patch size within maternal home ranges. In the OZ, female neonate survival was positively correlated with birth mass, male neonate survival was not affected by birth mass, and survival of both sexes was negatively correlated with grassland patch density. We suspect these habitat metrics were related to predator searching efficiency and abundance. In the highly fragmented GP, predators might be able to easily search the largest cover habitat patches, whereas in the more contiguous OZ landscape, where cover habitat patch sizes were > 10 times the size of patches in the GP, large patches might be difficult for predators to search efficiently. Therefore, we recommend managers consider the larger landscape context when making habitat management decisions to increase white-tailed deer population productivity. © 2019 The Wildlife Society. |