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Context: Animal-habitat relationships tend to manifest at specific spatial scales. Accurately identifying these scales and accounting for the variance in habitat selection across them is crucial for linking habitat selection patterns to the ecological processes giving rise to them. Although this fundamental issue has long been recognized, it has been seldom addressed empirically in habitat selection studies. Objectives: In this study, we investigated how spatial scale influences the outputs of habitat selection analyses. Furthermore, we examined whether the effect of spatial scale varies among individual animals and whether these effects could be predicted via intrinsic or extrinsic factors. Methods: We used a dataset collected from 485 GPS-collared white-tailed deer (Odocoileus virginianus) across three study sites in Missouri, USA to model habitat selection at 65 spatial scales from 900 m2 to 15 km2 using integrated step selection functions. To investigate potential drivers of spatial scaling we used multiple linear regression to model how scale of effect, defined as the spatial scale at which model AIC was minimized, could be predicted by intrinsic (age, sex, and home range size) and extrinsic factors (study site, season, mean percentage forest in home range, mean distance to nearest road in home range). Results: Scale of effect varied substantially among individuals, and individual variation in scale of effect was predicted by home range size, study site, and proportion of forest within a home range. In contrast, other intrinsic and extrinsic factors had little to no relationship with scale of effect. Parameter coefficients for forest cover and distance to nearest road varied strongly with opposing directionality of responses across spatial scales, revealing that spatial scale may bias habitat selection analyses. Coefficients were both positive and negative at different scales for an average of 63.2%individuals, and no single spatial scale resulted in the scale of effect more than 9.0% of the time. Conclusions: Our study demonstrates that spatial scale can strongly influence model parameter coefficients, thereby raising questions about the conventional interpretation of habitat selection analyses. We discuss outstanding issues regarding the comparability of results across study sites and the future of multi-scale habitat selection analyses. [ABSTRACT FROM AUTHOR]

Despite the key roles that dispersal plays in individual animal fitness and meta‐population gene flow, it remains one of the least understood behaviors in many species. In large mammalian herbivores, dispersals might span long distances and thereby influence landscape‐level ecological processes, such as infectious disease spread. Here, we describe and analyze an exceptional long‐distance dispersal by an adult white‐tailed deer (Odocoileus virginianus) in the central United States. We also conducted a literature survey to compare the dispersal to previous studies. This dispersal was remarkable for its length, duration, and the life history stage of the dispersing individual. Dispersal is typical of juvenile deer seeking to establish postnatal home ranges, but this dispersal was undertaken by an adult male (age = 3.5). This individual dispersed ~300 km over a 22‐day period by moving, on average, 13.6 km/day and achieving a straight‐line distance of ~215 km, which was ~174 km longer than any other distance recorded for an adult male deer in our literature survey. During the dispersal, which occurred during the hunting season, the individual crossed a major river seven times, an interstate highway, a railroad, and eight state highways. Movements during the dispersal were faster (mean = 568.1 m/h) and more directional than those during stationary home range periods before and after the dispersal (mean = 56.9 m/h). Likewise, movements during the dispersal were faster (mean = 847.8 m/h) and more directional at night than during the day (mean = 166.4 m/h), when the individual frequently sheltered in forest cover. This natural history event highlights the unpredictable nature of dispersal and has important implications for landscape‐level processes such as chronic wasting disease transmission in cervids. More broadly, our study underscores how integrating natural history observations with modern technology holds promise for understanding potentially high impact but rarely recorded ecological events. [ABSTRACT FROM AUTHOR]

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. We quantified survival rates and determined if neonate survival to 8 weeks was affected by weekly maternal habitat use in 2 different eco‐regions of Missouri, USA. We conclude that managers should consider the larger landscape context when making habitat management decisions to increase white‐tailed deer population productivity. [ABSTRACT FROM AUTHOR]

ABSTRACT Population growth rates of cervids are sensitive to changes in adult female survival, but fawn recruitment tends to be the population vital rate most susceptible to density-dependent population-level influences. We conducted a study of fawn survival rates and related biology in northwest Crockett County, Texas, USA, during 2004-2007 in an area where white-tailed deer ( Odocoileus virginianus) and mule deer ( O. hemionus eremicus) existed sympatrically. Our fawn study was justified by the need to explain annual variation in female-to-fawn ratios apparent during field surveys. Using vaginal implant transmitters in radio-marked adult females to locate birth sites, we captured, weighed, and radio-collared fawns on 4 privately owned ranches. We monitored collared fawns daily and investigated mortalities within 24 hours of receiving a mortality signal to determine cause of death. When possible, we collected thymus glands to assess body condition. We captured 170 fawns (64 white-tailed deer; 106 mule deer), of which 145 were of known-age from collared females, and found that relatively heavy adult females birthed relatively heavy fawns. We also noted that mass gain of fawns and mass of fawns' thymus glands were very low compared to other studies of fawns. We documented mortalities: 47 by predation, 47 by sickness-starvation, 1 by conspecific trauma, and 3 undeterminable. Bobcats ( Lynx rufus) were responsible for nearly all fawn predation; thymus gland and fawn mass data indicated that bobcats did not select weaker fawns. We used proportional hazards regression to assess factors influencing fawn survival and competing risks of mortality and made comparisons between the species when possible. We censored 6 fawns from our analyses and found that half of mortalities occurred within 15 days postpartum, and 12 of the 139 known-age fawns (9%) died within 25 m of the birth site. Fawn survival was 78% at 6 days old, which was the median estimated age-at-capture of fawns from unknown adults. Annual fawn survival rate ranged from 50% for fawns born in 2004 to 17% for fawns born in 2006, with no overall effect of species. Fawn survival was greatest in 2004 when rain during the May-August late-gestation and lactation period was greatest. Mule deer fawns succumbed more to sickness-starvation than did white-tailed deer fawns. Rates of sickness-starvation and predation increased with deviance from mean annual birth dates and with reduced rain during the late-gestation and lactation period. Early fawn survival increased with relative fawn mass, and sex became important at about 30 days postpartum, after which males were at greater risk of sickness-starvation. Lunn-McNeil competing-risks models suggested some interaction between sickness-starvation and predation. Fawn mortality, mass gain, thymus mass, and weaning data indicated that the populations of both deer species were chronically stressed near a carrying capacity that fluctuated annually with rain and that adult females invested little energy in rearing fawns relative to captive females. © 2017 The Wildlife Society. [ABSTRACT FROM AUTHOR]