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The visual capabilities of prey species such as white-tailed deer (Odocoileus virginianus) must be specialized to enhance predator detection and traverse a complex physical environment. Although aspects of the visual system of deer have been investigated, there has been no evaluation of the species' spatial resolution abilities. We used a behavioral assay to estimate visual acuity of three adult female deer using operant conditioning techniques. We estimated the spatial resolution is between four and six cycles/degree. Our results suggest the white-tailed deer eye allows relatively low spatial resolution, consistent with prior studies that reported high temporal resolution. The combination of low spatial resolution and high temporal resolution allows for efficient detection of movement and enhanced capability to transverse a complex environment., INTRODUCTION The ecological adaptations of vision in mammals allows enhanced ability to detect and avoid predators, negotiate various environments, and obtain food resources (Kiltie, 2000; Souza el al, 2011). Spatial [...]

Disturbance of wildlife from aircraft during aerial surveys could affect behavior or displace animals, causing them to cross multiple transects resulting in double counting or increasing likelihood of them seeking cover thereby impacting detection probability. We monitored 14 GPS‐instrumented male white‐tailed deer (Odocoileus virginianus) during helicopter surveys to evaluate if surveys influenced behavior. We collected GPS locations at 10‐min intervals during helicopter flights (i.e., 0700–1000 hours) and determined which individuals were contacted (i.e., within the flight transect at the moment of flyover whether detected or not) by the helicopter. We evaluated activity rates (% of seconds active during 10‐min fix interval) and movements (m) of contacted and non‐contacted deer using generalized linear mixed effects models (GLMMs) and habitat selection using step‐selection functions (SSFs). Activity rates of deer did not differ between contacted and non‐contacted individuals, however, contacted deer had shorter step‐lengths. There was no difference in selection of vegetative cover between contacted and non‐contacted individuals. Deer that were in close proximity to helicopter flyovers (i.e., 100 m on either side of the aircraft) reduced their step‐lengths, potentially decreasing detection probability. We found no evidence that disturbance from helicopter flyovers result in deer altering habitat selection or fleeing in a manner that could result in double counting. Instead, it appears deer disturbed by surveys are more likely to reduce movement. [ABSTRACT FROM AUTHOR]

Extreme climatic events (ECEs) are increasing in frequency and intensity and this necessitates understanding their influence on organisms. Animal behaviour may mitigate the effects of ECEs, but field studies are rare because ECEs are infrequent and unpredictable. Hurricane Irma made landfall in southwestern Florida where we were monitoring white-tailed deer (Odocoileus virginianus seminolus) with GPS collars. We report on an opportunistic case study of behavioural responses exhibited by a large mammal during an ECE, mitigation strategies for reducing the severity of the ECE effects, and the demographic effect of the ECE based on known-fate of individual animals. Deer altered resource selection by selecting higher elevation pine and hardwood forests and avoiding marshes. Most deer left their home ranges during Hurricane Irma, and the probability of leaving was inversely related to home range area. Movement rates increased the day of the storm, and no mortality was attributed to Hurricane Irma. We suggest deer mobility and refuge habitat allowed deer to behaviourally mitigate the negative effects of the storm, and ultimately, aid in survival. Our work contributes to the small but growing body of literature linking behavioural responses exhibited during ECEs to survival, which cumulatively will provide insight for predictions of a species resilience to ECEs and improve our understanding of how behavioural traits offset the negative impacts of global climate change. [ABSTRACT FROM AUTHOR]

1. Bateman's principle, stating that female fitness is maximised by increasing longevity, suggests females are likely to exhibit a stronger immune response than males. Applying these ideas to maturation, it is predicted that immature beetles will also show enhanced immunity. This study looks at how life-history strategies interplay with infection responses in a well-established immunological model, the burying beetle, Nicrophorus vespilloides (Herbst (Silphidae)), and a pathogenic bacteria, Photorhabdus luminescens (Thomas and Poinar (Enterobacteriaceae)). 2. To test this, the immune enzyme phenoloxidase ( PO) and bacterial loads in sexually mature and immature beetles were tested over time after injection with P. luminescens, and survival was monitored. Breeding after infection was also tested. 3. Bacterial loads were lower in females than males, and clearance seems more prolonged in immature than mature beetles, and both these groups showed increased survival, supporting the application of Bateman's principle to the effects of maturation and sex on immunity. 4. Mature beetles were found to undergo a shorter period of PO suppression after injection with bacteria. However, while high PO was beneficial up to 20 h post-infection, it became detrimental after that. This temporal factor has rarely been investigated but is shown here to be influential on the interpretation of PO activity, which is generally perceived as beneficial after infection. 5. A trade-off between reproduction and immunity was also found, revealed only by a highly pathogenic infection. This contrasts with the effects found in studies using non-pathogenic bacteria, suggesting an enforced, resource-based trade-off is the driving force behind the change, rather than an adaptive strategy. [ABSTRACT FROM AUTHOR]

Prey species must balance predator avoidance behavior with other essential activities including foraging, breeding, and social interactions. Anti-predator behaviors such as vigilance can impede resource acquisition rates by altering foraging behavior. However, in addition to predation risk, foraging behavior may also be affected by socio-sexual factors including breeding chronology and social interactions. Therefore, we investigated how time-of-day, distance-to-forest, group size, social interactions (presence of different sex-age class), and breeding chronology (pre-breeding, breeding, post-breeding seasons) affected probability of feeding (hereafter: feeding) for different sex and age-classes (mature males, immature males, adult females, and juveniles) of white-tailed deer at feed sites. We developed a set of candidate models consisting of social, habitat, reproductive, and abiotic factors and combinations of these factors. We then used generalized linear mixed models (GLMMs) to estimate the probability of feeding and used model averaging of competing models for multimodel inference. Each adult sex-age class’ feeding was influenced by breeding chronology. Juveniles were more likely to be feeding than adults in all seasons. Feeding increased with group size for all sex-age classes. The presence of a mature male negatively influenced the feeding of immature males and juveniles were more likely to be feeding when an adult female was present. Feeding decreased with increasing distance-to-forest for mature males but not for other sex-age classes. Our results indicate that each sex-age class modulates vigilance levels in response to socio-sexual factors according to the unique pressures placed upon them by their reproductive status and social rank. [ABSTRACT FROM AUTHOR]

ABSTRACT Although many aspects of white-tailed deer ( Odocoileus virginianus) biology and physiology have been studied thoroughly, few studies have examined deer perception. We obtained a behavioral measure of light-adapted visual sensitivity based on performance of 7 deer in forced-choice discrimination tests. We compared intensity thresholds at the short and long wavelengths of their purported visual spectrum. Utilizing an automated training device, we trained deer to discriminate between lit and unlit light-emitting diode (LED) lights expressing monochromatic wavelengths, and recorded performance across a series of decreasing intensities for each wavelength until deer could no longer discriminate the light stimulus. We regressed a best-fit logistic function to each deer's performance as intensity decreased at a single wavelength, demarcated the sensitivity threshold to that wavelength, and compared deer's sensitivity threshold across wavelengths. Our behavior-based sensitivity measurements agreed with previous estimates of white-tailed deer's cone photoreceptor sensitivity. We confirm that these cone photoreceptors contribute to deer behavior, and that deer have a greater perceptual sensitivity to shorter wavelengths and lower sensitivity to longer wavelengths. Our findings also suggest the deer have some sensitivity to ultraviolet light. The visual perception of the white-tailed deer is specialized for sensitivity during their crepuscular patterns, enables detection of predators along their horizon, and is well-adapted for a prey species. © 2014 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Although many aspects of white-tailed deer ( Odocoileus virginianus) biology and physiology have been studied thoroughly, few studies have confirmed deer cognitive perception, partly because of the difficulty of efficiently training sufficient numbers of deer to respond behaviorally in controlled experiments. We present a system that trains white-tailed deer to associate a supra-threshold, white-light stimulus with a food reward through operant conditioning techniques. The 'deer training apparatus' (DTA) automatically dispenses food, rings a start buzzer, randomly assigns a stimulus light over 1 of 2 troughs, and registers a deer's choice. If a deer goes to a trough with the light illuminated, then a correct choice is registered. All 6 deer tested met successful training criteria by Day 19, and a performance of 88.2% ± 3.9% correct choices by Day 25. We conclude that the DTA presents an effective and efficient way of training white-tailed deer, and provides an experimental platform for future research on behavior, perception, and preference. Thus, the DTA should be useful to researchers evaluating behavioral response of deer, and possibly other wild and domestic species, to various visual and auditory stimuli. © 2012 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Spatial genetic structure in white-tailed deer (Odocoileus virginianus) has been examined at regional scales, but genetic markers with the resolution to detect fine-scale patterns have appeared only recently. We used a panel of microsatellite DNA markers, radiotelemetry data, and visual observations of marked deer to study fine-scale social and genetic structure in a high-density population of white-tailed deer (12-20 deer/km²). We collected genetic data on 229 adult females, 102 of which were assigned to 28 social groups. Our results were consistent with the conceptual model of white-tailed deer social structure, where philopatric females form social groups composed of related individuals. Within-group relatedness values approached the expected value for 1st cousins (R = 0.103, SE = 0.033), but individuals among groups (R = -0.014, SE = 0.003) and overall (R = -0.009, SE = 0.003) were unrelated. Fixation indices revealed a significant departure from equilibrium values among social groups (FST = 0.076, SE = 0.007) and an excess of heterozygotes within groups (FIS = -0.050, SE = 0.018), consistent with theoretical expectations for mammal populations characterized by female philopatry and a polygynous mating system. Analyses of spatial autocorrelation indicated genetic structuring occurred at a very fine spatial scale, where pairs of adult females within 1 km were genetically nonindependent. The occurrence of fine-scale genetic and social structure has implications for the ecology and management of white-tailed deer, including habitat use and resource competition, offspring sex allocation theories, disease transmission, and the consideration of social behaviors in management. [ABSTRACT FROM AUTHOR]

Avian bycatch, a common and undesired occurrence in small mammal studies, should be minimized by researchers. We examined effects of trap covering, treadle color (copper or yellow plastic), trap size (mouse or rat), and trap weathering (traps <1 yr or ≥1 yr old) on avian bycatch during 3 years. We found that covered traps caught 81% fewer birds and 70% fewer small mammals than did uncovered traps, that mouse traps caught 30% more birds and 38% more small mammals than did rat traps, and no capture differences for treadle color or trap weathering. Covered traps effectively reduced avian bycatch and should be used when reduced small-mammal capture rates are acceptable. [ABSTRACT FROM AUTHOR]

Creation and maintenance of forested corridors to increase landscape heterogeneity has been practiced for decades but is a new concept in intensively managed southern pine (Pinus spp.) forests. Additionally, more information is needed on bat ecology within such forest systems. Therefore, we examined summer roost-site selection by evening bats (Nycticeius humeralis) in an intensively managed landscape with forested corridors in southeastern South Carolina, USA, 2003-2006. We radiotracked 53 (26 M, 27 F) adult evening bats to 75 (31 M, 44 F) diurnal roosts. We modeled landscape-level roost-site selection with logistic regression and evaluated models using Akaike's Information Criterion for small samples. Model selection results indicated that mature (≥40 yr) mixed pine--hardwood stands were important roost sites for male and lactating female evening bats. Upland forested corridors, comprised of mature pine or mixed pine--hardwoods, were important roosting habitats for males and, to a lesser extent, lactating females. Male roosts were farther from open stands and lactating female roosts were farther from mid-rotation stands than randomly selected structures. Our results suggest roost structures (i.e., large trees and snags) in mature forests are important habitat components for evening bats. We recommend maintaining older (>40 yr old) stand conditions in the form of forest stands or corridors across managed landscapes to provide roosting habitat. Furthermore, our results suggest that an understanding of sex-specific roost-site selection is critical for developing comprehensive guidelines for creating and maintaining habitat features beneficial to forest bats. [ABSTRACT FROM AUTHOR]

Basic knowledge of white-tailed deer (Odocoileus virginianus) hearing can improve understanding of deer behavior and may assist in the development of effective deterrent strategies. Using auditory brainstem response testing, we determined that white-tailed deer hear within the range of frequencies we tested, between 0.25-30 kilohertz (kHz), with best sensitivity between 4-8 kHz. The upper limit of human hearing lies at about 20 kHz, whereas we demonstrated that white-tailed deer detected frequencies to at least 30 kHz. This difference suggests that research on the use of ultrasonic (frequencies 20 kHz) auditory deterrents is justified as a possible means of reducing deer-human conflicts. [ABSTRACT FROM AUTHOR]

We evaluated the behavioral responses of white-tailed deer (Odocoileus virginianus) to 4 colors of wildlife warning reflectors (red, white, blue-green, and amber) that are purported to reduce the incidence of deer-vehicle collisions. We observed white-tailed deer behaviors relative to roads before and after installation of wildlife warning reflectors using a forward-looking infrared camera during 90 observation nights. We concluded that wildlife warning reflectors were ineffective in changing deer behavior such that deer-vehicle collisions might be prevented. [ABSTRACT FROM AUTHOR]

Deals with a study which analyzed the movements and ecology of white-tailed deer in the central Appalachians of West Virginia during summer 2001. Methodology of the study; Variation in the visitation rates of deer in three different wells; Factors that influence the distances that deer will make toward mineral sources.

Presents a study that assessed whether competition between white-tailed, fallow, red and roe deer could limit expansion of the white-tails in the Dobris Forest, Czech Republic. Information on interspecific agonistic interactions among the species of deer; Cause of anti-predatory origins among the deer; Use of the General Linear Models Procedure.

Simple Summary: Bait is often used to attract wildlife to enhance viewing opportunities, increase harvest rates, or to improve population survey methods for research and management purposes. However, baiting wildlife can alter animal behavior, leading to negative outcomes such as increased disease transmission, competition, and susceptibility to predation. Our objectives were to determine the effects of short-term baiting on male white-tailed deer behavior and distributions within several properties in southwestern Georgia, USA. We used cameras at baited and unbaited locations to assess the impacts of bait on deer space use within home ranges and to determine whether bait caused shifts in the distribution of home ranges during summer and winter surveys. We found little evidence that short-term baiting affected the distributions of home ranges on the landscape; however, we found evidence that space use within home ranges was affected by bait. By concentrating deer space use within seasonal home ranges, bait may enhance disease transmission and change harvest susceptibility. Bait is often used to increase wildlife harvest susceptibility, enhance viewing opportunities, and survey wildlife populations. The effects of baiting depend on how bait influences space use and resource selection at multiple spatial scales. Although telemetry studies allow for inferences about resource selection within home ranges (third-order selection), they provide limited information about spatial variation in density, which is the result of second-order selection. Recent advances in spatial capture-recapture (SCR) techniques allow exploration of second- and third-order selection simultaneously using non-invasive methods such as camera traps. Our objectives were to describe how short-term baiting affects white-tailed deer (Odocoileus virginianus) behavior and distribution. We fit SCR models to camera data from baited and unbaited locations in southwestern Georgia to assess the effects of short-term baiting on second- and third-order selection of deer during summer and winter surveys. We found little evidence of second-order selection during late summer or early winter surveys when camera surveys using bait are typically conducted. However, we found evidence for third-order selection, indicating that resource selection within home ranges is affected. Concentrations in space use resulting from baiting may enhance disease transmission, change harvest susceptibility, and potentially bias the outcome of camera surveys using bait. [ABSTRACT FROM AUTHOR]

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We evaluated partitioning of food resources among syntopic eastern red (Lasiurus borealis), Seminole (L. seminolus) and evening (Nycticeius humeralis) bats at the Savannah River Site, South Carolina, from June through August of 1996 and 1997. We compared diets to indices of relative prey availability, which were based on samples of the insect communities in bat foraging habitats and the amounts of time the bats foraged in each habitat. The relative proportions of insect orders consumed differed among the species. We recorded only minor differences between insect consumption and indices of prey availability, as assessed by insect light traps placed within foraging habitats. Our data suggest that Eastern red bats and evening bats altered their prey selection late in the summer. [ABSTRACT FROM AUTHOR]