Several factors influence neonate survival rates in white-tailed deer (Odocoileus virginianus), and an emphasis on predation as the primary limiting factor to neonate recruitment may serve to detract researchers from understanding other influential variables. We estimated survival and cause-specific mortality of white-tailed deer neonates in the absence of predators with an emphasis on assessing how birth mass, dam maturity, and weather covariates affect neonate survival. Additionally, we examined the influence of capture method (opportunistic searches vs. vaginal implant transmitter; VIT) on survival estimates. We captured 109 neonates using opportunistic capture (n = 55) and VITs (n = 54) in Sussex County, Delaware, USA, during 2016 and 2017. There are no established predator populations (i.e., black bear, bobcat, and coyote) within the study area. We observed greater 90-d survival rates in opportunistically captured neonates (0.69, 95% CI = 0.55-0.87) compared to VIT-captured neonates (0.44, 95% CI = 0.34-0.61), a difference driven by inobservance of early-life mortality events among neonates captured opportunistically. Natural causes excluding predation (e.g., disease, emaciation, and birth defects) accounted for all observed mortality (n = 42). Mortality related to disease, emaciation, and birth defects typically occurred in the first 7 d of life and was underrepresented in the opportunistically captured sample. Birth mass, dam age class, and precipitation influenced neonate mortality risk within the first 7 d of life, but no variables were associated with survival from 8 to 28 d of life. Non-predation-related mortality causes in our study area resulted in survival rates comparable to regions with established predator communities. Non-predation-related mortality may be the ultimate driving factor controlling neonatal survival in other regions but can be obfuscated by more proximal mortality sources, such as predation.

Restoring male age structure in white‐tailed deer populations has become an important objective for many state agencies aimed at improving herd dynamics. Limiting mortality in the yearling (1–2 yr old) age class is a primary consideration, and regional differences in climate, habitat characteristics, hunting regulations, and hunter behavior complicate the understanding of how specific factors influence the risk of mortality. We used Cox proportional hazard modeling to determine the effects of body size, mean distance to road, dispersal behaviors, use of forested land, and use of land open to public hunting on the risk of mortality for a population of radio‐collared, yearling males (n = 76) in Sussex County, Delaware, USA. Annual survival averaged 0.55 (95% CI = 0.45–0.68), with harvest accounting for 79% (26/33) of all mortalities. Measurements of body size (chest girth, shoulder height, and total length; cm) influenced dispersal probability but not dispersal distance. The best approximating model for mortality risk included a covariate for landownership, whereby mortality risk increased on public land. Among males who dispersed, longer‐distance dispersal was associated with reduced mortality, which contradicts previous research describing dispersal as a high‐risk behavior. The effect of landownership on mortality risk has not been previously identified, especially when regulations regarding harvest of yearling males are similar between landownership types. We observed annual survival rates of 0.69 (95% CI = 0.57–0.82) for deer apparently using private land exclusively during the hunting season, and 0.20 (95% CI = 0.11–0.48) for deer that used public land during the hunting season. Survival rates on private land were comparable to those of other regions actively managing male age structure. These results suggest survival of yearling males in the region is influenced by hunter harvest and the risks associated with dispersal may be minimal in areas where harvest pressure is low, although hunter harvest on public land may limit male age structure on a localized scale. © The Wildlife Society, 2019

Background: The vaginal implant transmitter is an effective tool in the study of neonatal survival rates for cervid species. The latest iterations of the vaginal implant transmitter use Global Positioning Systems and ultra-high frequency telemetry technology to create a self-monitoring system in which researchers receive near instantaneous notifications of parturition events via remote transmission. We deployed ultra-high-frequency radio-linked vaginal implant transmitters on 44 adult female white-tailed deer (Odocoileus virginianus) and assessed their performance and possible benefits to field research. Results: In 2016, 60% of the females expelled transmitters at the birth sites. Failure to locate a birth site was a result of technological failings (20%) and premature expulsions (20%). Following manufacturer updates in 2017, we observed an apparent reduction in technology malfunctions (8%) but similar rates of premature expulsions (33%), which resulted in 58% of radio-linked transmitters expelled at birth sites. We located similar numbers of neonates per device across both years. The likelihood that researchers would locate > 1 neonate at or near the birth site was greater for radio-linked transmitters than has been reported in studies using traditional vaginal implant transmitters. Conclusions: Radio-linked transmitters allow researchers to increase sample size, expand spatial distribution of study animals, and reduce personnel requirements.

Many soybean (Glycine max) producers consider white-tailed deer (Odocoileus virginianus) to be costly crop pests, and chemical repellants are an option for reducing deer damage. To cost-effectively utilize repellants, it is crucial to know the spatial and temporal aspects of deer-browsing patterns. During 2003During -2006 in Delaware, USA, we investigated where and when browsing was most intense within crop fields and subsequently had the greatest effect on yield of soybeans at an estimated deer density of 21 deer/km 2 . We systematically placed plots (n ¼ 1,340) at 10-m intervals from the forest edge. We designed protection treatments to mimic the effect of chemical repellents. We systematically assigned types of protection treatments to plots and protected plots using fencing. Protection did not affect the yield of double-crop soybeans in any year. In 2 years of the study (2003 and 2006), protection did not affect full-season soybean yield. In the other 2 years (2004 and 2005), plots protected from deer browse yielded less than plots that were not protected. Yield tended to be the lowest in the first 20 m from the forest edge, but there was no interaction effect between deer browsing and distance from the forest edge for any year or crop type. We found that deer browsing increased yield, possibly because browsing increases branching of individual plants, and thus the number of bean pods. We also found that the distance from the forest edge affected yield, but independently of deer browsing. Deer damage to soybeans, at a deer density of 21 deer/km 2 , may be more of a perceptual issue and the use of a chemical repellant would not be justified. Ó

Individual animals vary in their selection of habitat as a function of sex, age, and experience. Such individual heterogeneity is important when decomposing segments of the population that may or may not respond to habitat or population management, or when targeting management that has greater potential for increasing demographic responses (e.g., survival). We examined individual heterogeneity in habitat selection during the hunting season using multilevel step selection models for 59 adult (≥2.5 yr old) white-tailed deer (Odocoileus virginianus) of both sexes. We used fractal analysis to determine the scale at which animals perceived and responded to the landscape, and modeled selection using covariates for use of agriculture, wetland, edge, forest interior, and distance to road. We tested for differences in individualspecific habitat selection between age classes and modeled survival as a function of individual-specific selection using proportional hazard modeling. At the population level, males selected for agriculture and forest interior and avoided roads, while adult females selected for agriculture. Individual-specific selection of forest interior differed between age classes in males, with mature males selecting interior forest less frequently than immature males. Risk of mortality was related negatively to individual-specific selection for wetland areas in males and forest interior for females. No habitat variables that were selected for or avoided at the population level influenced mortality risk at the individual level, suggesting management efforts based on traditional population-level analysis may be misguided. Managers attempting to influence population dynamics via habitat and harvest management should be aware of the substantial heterogeneity in habitat selection among individual animals before implementing costly practices that may not be effective for their objectives.