Patterns of Hemorrhagic Disease in White-Tailed Deer (Odocoileus Virginianus) in the Great Plains of the USA, 1982-2020.

Hemorrhagic disease (HD) of deer is caused by epizootic hemorrhagic disease virus (EHDV) or bluetongue virus (BTV) and is considered one of the most important viral diseases of white-tailed deer (Odocoileus virginianus). Despite evidence of changing patterns of HD in the northeastern and upper midwestern US, the historical and current patterns of HD in the Great Plains remain poorly described. We used results from an annual survey documenting HD mortality to characterize historic and current patterns of HD in the northern and central Great Plains (North Dakota, South Dakota, Nebraska, Kansas, and Oklahoma), US, between 1982 and 2020. Further, we assessed temporal change using linear regression to determine change in annual reporting intensity (percentage of counties in a state with reported HD) and change in reporting frequency (the number of years a county or state reported HD) during each decade between 1982 and 2020. Across the 38-yr study period, HD reports expanded northeast across latitude and longitude. Intensity of HD reports significantly increased during this period for three (North Dakota, South Dakota, Kansas) of five states examined. Frequency of reports also increased for all five states. Such changes in northern latitudes might lead to increased deer mortality in regions where HD epizootics have been historically less frequent. Understanding how patterns of HD are changing on the landscape is important when considering future deer management in the face of other mortality factors.

Female Deer Movements Relative to Firearms Hunting in Northern Georgia, USA.

Perceived risk associated with hunters can cause white-tailed deer (Odocoileus virginianus) to shift their activity away from key foraging areas or alter normal movements, which are important considerations in managing hunting and its effects on a population. We studied the effects of seven firearms hunts on the movements of 20 female deer in two Wildlife Management Areas within the Chattahoochee National Forest of northern Georgia, USA, during the 2018-2019 and 2019-2020 hunting seasons. Deer populations and the number of hunters in our study area have declined significantly since the 1980s. In response, hunting regulations for the 2019-2020 hunting season eliminated opportunities for harvesting female deer. To evaluate the indirect effects of antlered deer hunting on non-target female deer, we calculated 90% utilization distributions (UDs), 50% UDs, and step lengths for pre-hunt, hunt, and post-hunt periods using the dynamic Brownian bridge movement model. Data included 30 min GPS locations for 44 deer-hunt combinations. Pre-hunt 50% UDs (x- = 7.0 ha, SE = 0.4 ha) were slightly greater than both hunt (x- = 6.0 ha, SE = 0.3 ha) and post-hunt (x- = 6.0 ha, SE = 0.2 ha) 50% UDs (F = 3.84, p = 0.03). We did not detect differences in step length, nor did we detect differences in size or composition of 90% UDs, among the periods. Overall, our results suggest that the low level of hunting pressure in our study area and lack of exposure to hunters led to no biologically significant changes in female deer movements. To the extent of the findings presented in this paper, adjustments to the management of hunting in our study area do not appear to be necessary to minimize hunting-related disturbances for female deer. However, managers should continue to consider female deer behavior when evaluating future changes to hunting regulations.

A Review of Cervidae Visual Ecology.

This review examines the visual systems of cervids in relation to their ability to meet their ecological needs and how their visual systems are specialized for particular tasks. Cervidae encompasses a diverse group of mammals that serve as important ecological drivers within their ecosystems. Despite evidence of highly specialized visual systems, a large portion of cervid research ignores or fails to consider the realities of cervid vision as it relates to their ecology. Failure to account for an animal's visual ecology during research can lead to unintentional biases and uninformed conclusions regarding the decision making and behaviors for a species or population. Our review addresses core behaviors and their interrelationship with cervid visual characteristics. Historically, the study of cervid visual characteristics has been restricted to specific areas of inquiry such as color vision and contains limited integration into broader ecological and behavioral research. The purpose of our review is to bridge these gaps by offering a comprehensive review of cervid visual ecology that emphasizes the interplay between the visual adaptations of cervids and their interactions with habitats and other species. Ultimately, a better understanding of cervid visual ecology allows researchers to gain deeper insights into their behavior and ecology, providing critical information for conservation and management efforts.

Population Dynamics of a Declining White-Tailed Deer Population in the Southern Appalachian Region of the United States.

Although generally abundant, white-tailed deer (Odocoileus virginianus) populations in the southeastern United States have recently experienced several localized declines attributed to reduced fawn recruitment following the establishment of coyotes (Canis latrans). The Southern Appalachians is a mountainous region suggested to be experiencing white-tailed deer declines, as harvest numbers and hunter success rates have substantially decreased in northern Georgia since 1979. Low fawn survival (16%) was also recently documented in the Chattahoochee National Forest (CNF) in northern Georgia, necessitating further examination. We radio-collared 14 yearling and 45 adult female white-tailed deer along with 71 fawns during 2018-2020 in the CNF to estimate field-based vital rates (i.e., survival and fecundity) and parameterize stage-structured population models. We projected population growth rates (λ) over 10 years to evaluate the current rate of decline and various other management scenarios. Our results indicated that the observed population would decline by an average of 4.0% annually (λ = 0.960) under current conditions. Only scenarios including antlerless harvest restrictions in addition to improved fawn survival resulted in positive growth (λ = 1.019, 1.085), suggesting these measures are likely necessary for population recovery in the region. This approach can be applied by wildlife managers to inform site-specific management strategies.

Influence of visual perception on movement decisions by an ungulate prey species.

Visual perception is dynamic and depends on physiological properties of a species' visual system and physical characteristics of the environment. White-tailed deer (Odocoileus virginianus) are most sensitive to short- and mid-wavelength light (e.g. blue and green). Wavelength enrichment varies spatially and temporally across the landscape. We assessed how the visual perception of deer influences their movement decisions. From August to September 2019, we recorded 10-min locations from 15 GPS-collared adult male deer in Central Florida. We used Hidden-Markov models to identify periods of movement by deer and subset these data into three time periods based on temporal changes in light environments. We modeled resource selection during movement using path-selection functions and simulated 10 available paths for every path used. We developed five a priori models and used 10-fold cross validation to assess our top model's performance for each time period. During the day, deer selected to move through woodland shade, avoided forest shade, and neither selected nor avoided small gaps. At twilight, deer avoided wetlands as cloud cover increased but neither selected nor avoided other cover types. Visual cues and signals are likely more conspicuous to deer in short-wavelength-enriched woodland shade during the day, while at twilight in long-wavelength-enriched wetlands during cloud cover, visual cues are likely less conspicuous. The nocturnal light environment did not influence resource selection and likely has little effect on deer movements because it's relatively homogenous. Our findings suggest visual perception relative to light environments is likely an underappreciated driver of behaviors and decision-making by an ungulate prey species.

Assessing springtime vertebrate prey of sympatric mesopredators in the southeastern United States using metabarcoding analysis.

Coyotes (Canis latrans) colonized the eastern United States over the last century and formed a 3-species predator guild with bobcats (Lynx rufus) and gray foxes (Urocyon cinereoargenteus) across much of the southeastern United States. Diets among the three species vary along with respective impacts on game species such as white-tailed deer (Odocoileus virginianus) and wild turkeys (Meleagris gallopavo). To determine predation impacts on vertebrate prey and dietary overlap in consumption of prey items, we assessed diets of coyote, bobcat, and gray fox during spring, coinciding with white-tailed deer fawning and wild turkey nesting and brood rearing. We sampled across three sites along the Savannah River in South Carolina from mid-May through mid-June of 2020-2021. We collected 180 scat samples along 295.9 kilometers (71.1-122.4 km/site) of unpaved secondary roads and used DNA metabarcoding to determine vertebrate diet items. We identified predator species of scat using DNA metabarcoding and species-specific mtDNA fragment analysis (153 were coyote, 20 bobcat, and seven gray fox). Overall, we found evidence that two species, coyote and bobcat, consumed deer while all three consumed turkeys. Frequency of deer in the diet varied across sites for coyotes from 62-86% and wild turkey was present with a frequency of occurrence of 9% for coyotes, 5% for bobcats, and 14% for gray fox. Vertebrate diet specialization was evident across predator species with high frequency of deer in coyote diets, rabbits and small mammals in bobcat diets, and herpetofauna in gray fox diets. During deer fawning and wild turkey nesting and brood rearing, dietary overlap appears to be mediated by disparate selection of prey items, which reduced competition among coyotes, bobcats, and gray foxes. Use of DNA metabarcoding may augment our understanding of dietary preferences within this predator guild by providing increased resolution of diet composition among important game species.

White-tailed deer (Odocoileus virginianus) fawn survival and the influence of landscape characteristics on fawn predation risk in the Southern Appalachian Mountains, USA.

In the Southern Appalachian region of the United States, harvest data has indicated the occurrence of low deer densities while exposing a trend of declining white-tailed deer (Odocoileus virginianus) populations over the past several decades in northern Georgia. A triumvirate of increasing fawn predator populations reside in the Southern Appalachian Mountains including coyotes (Canis latrans), black bears (Ursus americanus) and bobcats (Lynx rufus). This region is also characterized by a homogenous landscape composed of mature forests and sparse understory vegetation, likely lacking adequate cover to offer fawns refugia from predators. Our objectives were to estimate survival and cause-specific mortality rates of fawns while assessing a possible link between mortality risk, intrinsic fawn characteristics (i.e., birth mass, Julian birth date, sibling status), and landscape features within fawn usage areas. During 2018-2020, we radio-collared 71 fawns within the Chattahoochee National Forest of northern Georgia, USA and monitored survival to 12 weeks of age. We observed low fawn survival (cumulative = 0.157, 95% CI = 0.091-0.273; vaginal implant transmitter = 0.196, 95% CI = 0.096-0.403) with predation as the leading cause of all known mortalities (45 of 55 mortalities; 82%) due primarily to coyotes (n = 22), black bears (n = 12), and bobcats (n = 7). Relationships between landscape features and fawn predation risk were minimal with only one informative covariate. Increasing amounts of early successional land cover within fawn usage areas decreased fawn mortality risk within the first 20 days of life, but elevated mortality risk thereafter. All fawns with any amount of early successional land cover in their usage areas died of predation (n = 13) at various time intervals, suggesting limited areas of potential fawning cover may be targeted by predators. However, fawn predation risk seemed to be high regardless of landscape covariates due to the limited number of surviving fawns. Coyote-caused mortality occurred over a longer period at a consistently higher magnitude than all other forms of mortality, indicating possible delayed prey-switching behavior and coyote predation as an important factor of fawn survival. The low recruitment of fawns influenced by high predation rates and homogenous habitat conditions is likely the cause of deer population declines in the region.

Drivers of support for citizen science across state wildlife management agencies in the United States.

Citizen science (CS) is gaining recognition as a valuable approach to meet data needs for environmental projects while fostering collaboration between scientists and members of the public. Despite increasing implementation of CS by natural resource entities, organizations' motivations for engaging in CS remain poorly understood. We examined the utility of the theory of planned behavior (TPB) and social exchange theory (SET) in identifying factors influencing support of CS by scientific organizations. To test predictions of the TPB and SET theories, we surveyed (quantitative, web based) state wildlife agency staff in the United States on their perceptions of organizational engagement in CS. We divided questions that measured TPB items into individual and organizational components to address the influence of personal- and organization-level decision-making on staff perceptions and attitudes. We used structural equation modeling to identify key constructs that influence staff support of CS in state wildlife agencies. The survey yielded 627 responses across 44 states. Both TPB and SET constructs accurately predicted staff support of CS; however, measures from SET (e.g., public engagement benefits and costs of CS to scientific credibility) were most influential (i.e., TPB constructs had less impact). Our findings indicate that organizational support for CS is primarily influenced by assessment of trade-offs among perceived costs and benefits. Indicators of support for CS were further elucidated by including measures from the TPB model. Based on our results, we suggest that natural resource entities give careful consideration to CS project design, develop thorough communication and data management plans, and practice iterative evaluation of CS project productivity.

Impulsores del apoyo a la ciencia ciudadana entre las agencias estatales de gestión de fauna en los Estados Unidos Resumen Cada vez se reconoce más a la ciencia ciudadana (CC) como una estrategia valiosa para cumplir con las necesidades informativas de los proyectos ambientales, a la vez que promueve la colaboración entre los científicos y el público. Aunque es cada vez mayor la implementación de la CC por parte de las entidades de recursos naturales, todavía hay poca información sobre la motivación de las organizaciones para participar en la CC. Analizamos la utilidad de la teoría del comportamiento planeado (TCP) y la teoría del intercambio social (TIS) en la identificación de los factores que influyen sobre el apoyo de las organizaciones científicas a la CC. Sondeamos (cuantitativamente y en línea) al personal de las agencias estatales de los Estados Unidos sobre sus percepciones de la participación organizacional en la CC para evaluar las predicciones de ambas teorías. Dividimos las preguntas que medían los objetos de la TCP en componentes individuales y organizacionales para abordar la influencia de la toma de decisiones a nivel personal y organizacional sobre las actitudes y percepciones del personal. Usamos modelos de ecuación estructural para identificar los constructos clave que influyen sobre el apoyo a la CC por parte del personal de las agencias estatales de fauna. El sondeo aportó 627 respuestas de 44 estados. Los constructos de ambas teorías pronosticaron correctamente el apoyo a la CC por parte del personal; sin embargo, las medidas de la TIS (por ejemplo, los beneficios de la participación del público y los costos de la CC en la credibilidad científica) tuvieron la mayor influencia (los constructos de la TCP tuvieron un menor impacto). Nuestros resultados indican que el apoyo organizacional hacia la CC está influenciado principalmente por la valoración de las compensaciones entre los costos y beneficios percibidos. Los indicadores del apoyo a la CC se esclarecieron más con la inclusión de las medidas del modelo de la TCP. Con base en nuestros resultados, sugerimos que las entidades de recursos naturales consideren cuidadosamente el diseño de proyectos de CC, desarrollen una comunicación minuciosa y planes de manejo de datos y practiquen la evaluación iterativa de la productividad de los proyectos de CC.

Recursive use of home ranges and seasonal shifts in foraging behavior by a generalist carnivore.

Coyotes (Canis latrans) colonized the southeastern United States over the last century as large predators, including the red wolf (Canis rufus) and eastern cougar (Puma concolor), were extirpated from the region. As a generalist carnivore, the coyote preys on white-tailed deer (Odocoileus virginianus) and various smaller mammals, birds, and vegetation. While resource selection by coyotes has been well documented at the home-range scale, little is known about their foraging behavior, which is an important factor in thoroughly understanding influences of coyotes on prey and sympatric carnivores. We assessed third-order resource selection of coyotes at sites across Alabama, Georgia, and South Carolina during 2015-2016. Using GPS collars, we tracked 41 resident coyotes across four calendar seasons and identified suspected foraging areas using recursive analysis where individuals repeatedly returned to known locations. We found that resident coyotes selected for open landcover types throughout the year, while avoiding primary and secondary roads. Additionally, resident coyotes avoided forested landcover types while selecting for forest edges except from April to June when they foraged within interior forest away from edges. Previous studies have documented substantive predation rates on white-tailed deer neonates by coyotes, and that fawn mortality may increase in forested landscapes away from forest edge. Our findings indicate that foraging coyotes may select forest cover types during spring where fawns are more vulnerable to predation. Additionally, there has been debate in the literature as to how coyotes obtain consistent levels of deer in their diets outside of fawning and fall hunting seasons. Our study indicates that use of road-kill carcasses by coyotes was an unlikely explanation for the presence of deer in coyote diets throughout the year, as coyotes in our study were not observed using roads during foraging excursions.

The Effect of Maternal Antibodies on Clinical Response to Infection with Epizootic Hemorrhagic Disease Virus in White-Tailed Deer (Odocoileus virginianus) Fawns.

We investigated whether naturally acquired maternal antibodies to epizootic hemorrhagic disease virus serotype 2 (EHDV-2) would protect white-tailed deer (Odocoileus virginianus) fawns against infection and clinical disease following an EHDV-2 challenge. We compared viremia and clinical response in 27-47-d-old, experimentally infected fawns with and without maternally derived antibodies to EHDV-2. Mild to moderate clinical signs were observed in four seronegative (maternal antibody-negative) fawns, which were viremic from 3 to 14 d postinoculation. Individual peak blood virus titers for seronegative fawns ranged from 104.3 to 106.3 median tissue culture infective doses (TCID50)/mL. In contrast, clinical signs were not observed in seropositive (maternal antibody-positive) fawns and a transient low-level viremia (≤102.4 TCID50/mL) occurred in two of six fawns. Our results indicated that the presence of maternally derived EHDV-2 antibodies in fawns prevents or greatly reduces clinical disease and the level and duration of EHDV-2 viremia.