An Evaluation of Life History Parameters of White-Tailed Deer (Odocoileus virginianus) in North Dakota

Life history characteristics of white-tailed deer (Odocoileus virginianus) have been documented in the Northern Great Plains, but limited information is available in regions dominated by grasslands. The objectives of our study were to document movements, cause-specific mortality, survival rates, and habitat selection of white-tailed deer. We captured and radiocollared 75 (62 adult female, 13 neonates) deer in the Wing-Tuttle region of North Dakota; 58 adult deer were residents, 21 were migrators, and 7 exhibited late season movements. We calculated 86 individual seasonal home ranges; mean 50 and 95% home ranges of resident animals (n = 58) were 1.38 and 6.82 km2 and were similar to those of migrating individuals (n = 21, 1.04 and 4.94 km2) and those of deer that exhibited late season movements (n = 7, 1.14 km2 and 5.82 km2). Natural causes (e.g., starvation, predation) were the greatest factors resulting in mortality of deer. Adult annual survival rates during 2010 and 2011 were 0.91 (SE = 0.04, n = 48) and 0.71 (SE = 0.06, n = 55), respectively. Adult seasonal survival rates were highest during post-hunt 2010 (1.0) and pre-hunt 2010 (1.0) but lowest during hunt 2010 (0.84) and post-hunt 2011 (0.81) periods. The majority of radiocollared adult female deer (2010; 78%, n = 47, 2011; 73%, n = 43) during the firearm season were located on posted private land and available for harvest by firearm hunters (80% in 2010, 84% in 2011). During summer 2011, we documented 13 (46%) neonate bed sites in grasslands, 7 (25%) in Conservation Reserve Program grasslands, 7 (25%) in forested cover, and 1 (4%) in alfalfa. We used our observations to test a previously published grassland bed site model for the Northern Great Plains that stated the probability of neonate bed site selection increased with increase of vertical height of vegetation; model validation resulted in an accuracy of 68.3%. Management for vertical height of grasslands would improve the quality of habitat for neonates during first 60 days of life. With limited movement outside management unit boundaries and natural causes dominating cause-specific mortality, regulating hunter harvest remains the primary tool for maintaining population goals.