White-tailed Deer Research Articles

Activity patterns and use of artificial water ponds by White-tailed deer (Odocoileus virginianus) in western Campeche

Artificial Water Ponds (AWP) are widely employed for preserving and managing white-tailed deer (Odocoileus virginianus) in arid, and tropical regions of Mexico. However, there is a significant knowledge gap concerning the impact of these AWP on white-tailed deer activity. To determine the effect of AWP on the ecological aspects of white-tailed deer, we assessed the visitation rates and activity patterns of this species in AWP and compared them with areas devoid of water such as Dirt Roads (DR) using camera traps during the dry season within the seasonal wetland region of Nicte Ha, situated in western Campeche, Mexico. The research was conducted in a highly seasonal tropical wetland area at the Nicte-Ha UMA in southwestern Campeche, México. We established set camera trap stations during the dry season of 2019, 2020, and 2021 in seven AWP and 12 DR that operated for at least 80 days and compared the white-tailed deer visitation rate (measured as the Relative Abundance Index, RAI) and activity patterns among both treatments and across the three studied years. We collected a total of 3,640 independent records of white-tailed deer (2,584 in AWP and 1,056 in DR) for three years, with a combined effort of 3,978 camera days (1,306 camera days in AWP and 2,672 in DR). Our analysis revealed that the Relative Abundance Index (RAI) was consistently higher in the AWP than the DR across the three study years. However, we examined RAI variations over the three years and observed differences in the AWP, while the DR exhibited a relatively stable pattern. In the case of the activity patterns, we observed that white-tailed deer were primarily diurnal, with a significant overlap in activity between the two treatment areas. Nonetheless, within the AWP, the species exhibited continuous daytime activity, whereas, in the PR, distinct activity peaks occurred during sunrise and sunset. The results show that the presence of AWP in Nicte Ha has important effects on the presence of white-tailed deer during the dry season since we observed that there is a higher RAI in the sites where there is AWP compared to the PR sites. In the case of activity patterns, the AWP sites maintain constant activity throughout the day compared to DR, where activity peaks associated with sunrise and sunset occur. Our results show the importance that this type of structure has for the management of the species during the dry season of the year in Nicte Ha and the potential benefits of these structures in tropical seasonal areas, especially under a scenario in which drought during the dry season may be more severe in the near future due to the global change.

Occupancy, relative abundance and activity patterns of three sympatric deer in ponds of Calakmul Biosphere Reserve, Campeche

Calakmul Biosphere Reserve is one of the largest tropical forests in the Americas, home to three species of deer, the white-tailed deer, Odocoileus virginianus, the Yucatan brown brocket deer, Odocoileus pandora, and the Central American red brocket deer, Mazama temama. Important ecological aspects on the conservation of these species have been poorly studied. The aim of this study was to determine the occupancy, relative abundance and activity patterns of these species through 9 years of camera-trapping in ponds of a Neotropical Forest in southern Mexico, contributing to the understanding of the ecological patterns and conservation of Neotropical deer. To determine abundance, occupancy and activity patterns, 18 ponds were monitored from 2014 to 2022. The general relative abundance index was used to calculate abundance and the temporal kernel density was used to evaluate the overlap in daily activity of the species. The dynamic occupancy model was used to obtain the occupancy, colonization, extinction and detection of deer, while species co-occurrence occupancy models were used to assess the interaction of water and species. White-tailed deer were the most abundant (Table 1) during the nine years of the study, with low pond occupancy, but with a high probability of colonization. The brown brocket deer was the one with the highest probability of occupancy, showing a low abundance (Table 1), followed by the red brocket deer, with a very low occupancy and abundance (Table 1). Interaction with water was positive in two of the three analyzed species and activity was diurnal for Odocoileus species and cathemeral for Mazama (Fig. 3). The use of ponds by deer is varied in quantity and activity, but they are important places for their development. The protection of the ponds should be fundamental for the conservation of the species in the area, being one of the few semi-perennial water sources and places of food and shelter for wildlife.

Use of artificial water troughs by deer in the Maya forest, México

Artificial water troughs have been implemented in the Calakmul region as a measure that contributes to the maintenance of wildlife populations during the drought season. The aim of this study was to estimate the use of artificial water troughs by three species of deer (Odocoileus virginianus, M. pandora, and Mazama temama) in the Maya Forest of Campeche in southeastern México. The study was carried out in the Calakmul Biosphere Reserve (CBR, in Spanish) in southeastern México. Seventy artificial water troughs were installed, most of them within the core areas of the CBR. Between December 2018 and August 2021, eight digital traps were placed in eight artificial water troughs to monitor the presence of deer. The Photographic Visit Index (PVI) was calculated, and the visit rates of each species were compared by sampling year for each monitoring station. Deer activity patterns were evaluated using circular statistics to assess whether there were differences between visiting times. Watson-Williams tests were performed during the different sampling months. The density of records was analyzed to identify the degree of overlap in the deer activity patterns. With a sampling effort of 4,672 nights/camera, we captured 477 records of O. virginianus, 229 of M. pandora, and three of M. temama using artificial water troughs in the CBR. Due to the scarce records of M. temama in water troughs, comparative analyses were performed only with the other two deer species. According to the PVI, in the case of O. virginianus, highly significant differences were found between the three sampling years (H = 12.575, df = 2, P < 0.001); similarly, M. pandora showed highly significant differences between sampling years (H = 9.29, df = 2, P = 0.001). Regarding activity patterns, O. virginianus is mainly diurnal, with peaks of activity in the early hours of the day (8:00 h to 9:00 h). M. pandora was also mainly diurnal, showing the highest peaks of activity in the early hours of the day and before dusk. O. virginianus and M. pandora regularly visit water troughs, and the presence of deer in water troughs responds to their need to drink water for thermoregulation. The activity pattern of deer was mainly diurnal; it is safer for both species to move during the day because predators were recorded constantly in the study area. The degree of overlap recorded between O. virginianus and M. pandora suggests that both species are active at the same times of the day.

Spatial Variation of Population Density and Age Structure of White-Tailed Deer (Odocoileus virginianus) in a Colombian Moor

Wildlife population density is affected by resource availability, predators and competitors, and anthropogenic stressors. Its analysis and the factors affecting it are important for conservation, use, or population control. Based on estimates of density and population parameters, together with niche modeling, previous studies considered that the white-tailed deer population at the Chingaza National Natural Park (NNP) is undergoing exponential growth due to the marginal influence of factors regulating its abundance, such as predators. The aim of this study was to evaluate the population density and age structure of the white-tailed deer in the Chingaza NNP, Colombia. To evaluate the population density and age structure of white-tailed deer in the Monterredondo and La Paila sectors of the Chingaza NNP, 10 transects were installed with circular plots in each. These were visited twice; in each visit, we collected all deer pellet groups, measuring each pellet to estimate its volume. Population density was calculated using the Eberhardt and Van Etten method and the semi-automated PELLET procedure using FSC and FAR techniques; the age structure was estimated by k-means and fuzzy clustering analyses. With the FAR technique, the estimated deer density was 2.09 ind/km2 in Monterredondo and 0.94 ind/km2 in La Paila. With PELLET, these values were 0.37 ± 0.4 ind/km2 for Monterredondo and 0.16 ± 0.2 ind/km2 for La Paila. The proportion of age classes (adult, juvenile, and fawn) was 1:0.29:0 for Monterredondo and 1:0.57:0.04 for La Paila. The population density of white-tailed deer in two sectors of the Chingaza NNP is not homogeneous, but shows temporal and spatial variations. Population density has decreased versus reports from previous studies in this same area, with the highest deer abundance recorded in 2004, mostly in the Monterredondo sector. The proportion of age classes suggests that the population is stable, as the largest proportion of individuals corresponds to the adult stage

Biogeographic analysis of population density of white-tailed deer in Mexico: Importance of the Protected Natural Areas and Wildlife Management Units

The white-tailed deer Odocoileus virginianus is the wildlife species with the greatest geographic distribution and economic importance in Mexico. This article presents a biogeographic analysis of the population density of this deer species by federal states, vegetation types, biogeographic provinces, and field methods, based on 200 selected studies. Estimates are highly variable and potentially biased due to the different field designs and statistical analyses. The national average density was estimated at 6.9 deer/km2 (SD = 5.1); specifically, 75.5 % of the estimates were less than 10 deer/km2, and only 5.5 % were greater than 15 deer/km2. The highest densities were obtained in the northern region by applying the strip transect counts; while estimations using the fecal group count method were more variable and were the most used method in temperate and tropical dry forest regions. The states with the highest densities were Coahuila, Tamaulipas, Jalisco, Morelos, Michoacán, and Durango. The highest densities were estimated in the xerophilous scrublands of the northeast, intermediate for temperate, tropical dry, and sub-deciduous forests; and the lowest in the tropical wet forest. The highest densities were reported for the Tamaulipeca province followed by the Altiplano Chihuahuense, Sierra Madre Occidental, Costa Pacífica, and Depresión del Balsas. The results of this analysis could guide management strategies for the conservation and sustainable use of this species in extensive UMAs and ANPs, and also to test ecological hypotheses. However, applying more rigorous field design and statistical analysis is important to obtain confident estimates of population density and other demographic parameters to monitor population dynamics.

Persistence of mule deer pellet groups on Chihuhuan Desert

The persistence of fecal or pellet groups is indispensable when using the pellet group counting technique to estimate population densities and relative abundances of deer, as well as other herbivores. This technique is widely employed worldwide, and in México, the majority of deer abundance estimates have been made using this tool. However, for mule deer (Odocoileus hemonious) in México, there is no data on the persistence of pellet groups, and there is only one study on white-tailed deer. The pellet group counting technique has two main methods: a) "Fecal Standing Crop," where the accumulated pellet groups in plots are counted in a single visit, and b) "Fecal Accumulation Rate," which estimates density based on the accumulation of new fecal groups between two sampling periods, initially requiring the removal of all fecal groups from plots and counting again after some time. Both methods require knowing the pellet group disappearance rate during the pellet group accumulation period. This information is fundamental to understanding the ecology and making precise decisions in the management and conservation of mammals, such as mule deer, a species that is declining in some regions of México. Due to the lack of studies on the persistence of pellet group of mule deer in México, the aim of this study was to determine the persistence of mule deer fecal groups and their color changes over time, to establish pellet accumulation periods for estimating population abundances without biases when using this technique in arid habitats. We monitored 102 fecal groups for four years in the Chihuahuan Desert, finding that pellet groups are only lost during the summer rainy season. All pellet groups deposited between October and May were present, and all pellet groups turned white only after the first summer rainy season. The persistence of pellet groups was similar across seasons (fall, winter, spring) and deposition years (2004 to 2006). Some pellet groups persisted for over four years. The data suggest that the only source of degradation of pellet groups is summer rains, and no degradation by biological agents, such as fungi or insects, was observed. In summary, in arid areas, to estimate deer use or density throughout the entire dry season through pellet group counting, it is suggested that only two visits with either of the mentioned techniques are needed. If "Fecal Standing Crop" is used, there is now certainty that all non-white pellets are post the summer rainy season. If the "Fecal Accumulation Rate" technique is used, there is certainty that there will be no loss of pellets groups between the accumulation period of the entire dry season, approximately 7.5 months later. By reducing the number of visits, it allows us to cover more sampling sites, expand the study area, and obtain more precise estimates that will help understand ecological aspects and make management decisions.

Long-term interactive impacts of the invasive shrub Lonicera maackii and white-tailed deer (Odocoileus virginianus) on a deciduous forest understory

AbstractWhite-tailed deer (Odocoileus virginianus) (hereafter, ‘deer’) and invasive plants affect forest understories, but few studies have investigated their interaction. We investigated long-term (11-yr) effects of excluding deer and removing the invasive shrub, Amur honeysuckle [Lonicera maackii (Rupr.) Herder], on plants in southwest Ohio. Deer exclusion enhanced tree seedling richness and density, but reduced annual and bare ground cover. Vine density was reduced by Lonicera, especially where deer were excluded. Seedlings of several tree species, the invasive shrub, burning bush [Euonymus alatus (Thunb.) Siebold], and the invasive vine, winter creeper [Euonymous fortunei (Turcz.) Hand.-Maz.], were indicator species of the deer exclosure by Lonicera removal treatment combination. The effect of deer on cover of native species depended on Lonicera treatment: where shrubs were removed, cover was higher where deer were excluded, but where shrubs were present, cover was higher where deer had access. We attribute these interactions to the reduced growth of, and shading by, Lonicera where deer had access and browsed this invasive shrub. Some of these effects were evident in the first 6 yr, but are now larger. Other effects were not evident in the earlier evaluation. These findings inform management of areas with high densities of deer and invasive shrubs palatable to deer. Control of only invasive shrubs will reduce native cover and not improve tree regeneration. Managing only deer will increase woody plants but reduce native cover. Management of both stressors is needed to promote tree regeneration and restoration of plant communities.

Automated Hyperspectral Feature Selection and Classification of Wildlife Using Uncrewed Aerial Vehicles

Timely and accurate detection and estimation of animal abundance is an important part of wildlife management. This is particularly true for invasive species where cost-effective tools are needed to enable landscape-scale surveillance and management responses, especially when targeting low-density populations residing in dense vegetation and under canopies. This research focused on investigating the feasibility and practicality of using uncrewed aerial systems (UAS) and hyperspectral imagery (HSI) to classify animals in the wild on a spectral—rather than spatial—basis, in the hopes of developing methods to accurately classify animal targets even when their form may be significantly obscured. We collected HSI of four species of large mammals reported as invasive species on islands: cow (Bos taurus), horse (Equus caballus), deer (Odocoileus virginianus), and goat (Capra hircus) from a small UAS. Our objectives of this study were to (a) create a hyperspectral library of the four mammal species, (b) study the efficacy of HSI for animal classification by only using the spectral information via statistical separation, (c) study the efficacy of sequential and deep learning neural networks to classify the HSI pixels, (d) simulate five-band multispectral data from HSI and study its effectiveness for automated supervised classification, and (e) assess the ability of using HSI for invasive wildlife detection. Image classification models using sequential neural networks and one-dimensional convolutional neural networks were developed and tested. The results showed that the information from HSI derived using dimensionality reduction techniques were sufficient to classify the four species with class F1 scores all above 0.85. The performances of some classifiers were capable of reaching an overall accuracy over 98%and class F1 scores above 0.75, thus using only spectra to classify animals to species from existing sensors is feasible. This study discovered various challenges associated with the use of HSI for animal detection, particularly intra-class and seasonal variations in spectral reflectance and the practicalities of collecting and analyzing HSI data over large meaningful areas within an operational context. To make the use of spectral data a practical tool for wildlife and invasive animal management, further research into spectral profiles under a variety of real-world conditions, optimization of sensor spectra selection, and the development of on-board real-time analytics are needed.

Culex erraticus (Diptera: Culicidae) utilizes gopher tortoise burrows for overwintering in North Central Florida.

Mosquito-borne diseases represent a significant threat to human and animal health in the United States. Several viruses, including West Nile, Saint Louis encephalitis, and Eastern equine encephalitis are endemic. In humans, the disease is typically detected during the summer months, but not during the winter months. The ability of these viruses to reemerge year after year is still not fully understood, but typically involves persistence in a reservoir host or vector during periods of low transmission. Mosquito species are known to overwinter at different life stages (adults, larvae, or eggs) in manufactured or natural sites. Gopher tortoise burrows are known to serve as refuge for many vertebrate and invertebrate species in pine savannas. In this study, we surveyed the interior of gopher tortoise burrows for overwintering mosquitoes. We identified 4 species (Anopheles crucians s.l., Culex erraticus, Mansonia dyari, and Uranotaenia sapphirina). Cx. erraticus was the most abundant, and its presence and abundance increased in winter months, implying that this species utilized gopher tortoise burrows for overwintering. Bloodfed Cx. erraticus and An. crucians s.l. females were detected. While An. crucians s.l. fed exclusively on the white-tailed deer, Cx. erraticus had a more diverse host range but fed primarily on the gopher tortoise. Tortoises and other long-lived reptiles like the American alligator have been shown to sustain high viremia following West Nile virus (WNV) and Eastern equine encephalitis virus (EEEV) infection and therefore could play a role in the maintenance of these viruses. In addition, Cx. erraticus is naturally infected with WNV and is a known bridge vector for EEEV. As such, these overwintering sites may play a role in perpetuating over-winter arboviral activity in Florida.

In Vitro Protection and Titer Duration of Anthrax-Specific Antibodies Following Subcutaneous Vaccination of White-tailed Deer (Odocoileus virginianus) with Bacillus anthracis Sterne 34F2 Strain Spores.

Outbreaks of anthrax, caused by the soilborne bacterium Bacillus anthracis, are a continuous threat to free-ranging livestock and wildlife in enzootic regions of the United States, sometimes causing mass mortalities. Injectable anthrax vaccines are commercially available for use in livestock, and although hand injection is not a cost- or time-effective long-term management plan for prevention in wildlife, it may provide a tool for managers to target selectively animals of high conservation or economic value. Vaccine-induced anthrax-specific antibody responses have been reported previously in white-tailed deer (Odocoileus virginianus), but the protective nature was not determined. In this study, five white-tailed deer were subcutaneously vaccinated with one dose (1 mL) of the Anthrax Spore Vaccine. Eight blood collections by jugular venipuncture were conducted over 146 d to measure the anthrax-specific antibody response in each deer's serum over time. Antibodies were first detected by ELISA and later with toxin neutralization assays to estimate in vitro protection. Average peak absorbance by ELISA occurred at 14 d postvaccination, whereas average peak in vitro protection occurred at 28 d postvaccination. Observed in vitro protection on average for white-tailed deer after this single-dose vaccination protocol lasted 42-56 d postvaccination, although three individuals still maintained lethal toxin-neutralizing serum antibody titers out to 112 d postvaccination. Vaccination responses were variable but effective to some degree in all white-tailed deer.

Immobilisation efficacy of conducted electrical weapons on captive white-tailed deer

Context Wildlife emergencies (e.g. injured animals) often require capture or humane dispatch of animals to resolve the situation. Conducted electrical weapons (CEWs) have the potential to immobilise white-tailed deer (Odocoileus virginianus) for a short duration to avoid potential risks of extended immobilisation (e.g. chemical immobilisation) and increase safety for managers and the public during humane killing by gunshot. Aims To test rapid immobilisation with minimal long-term physiological consequences of CEW immobilisation of white-tailed deer. Methods We arranged five treatment groups of captive deer, including (1) chemical immobilisation with 5-s CEW exposure (n = 5), (2) chemical immobilisation with 15-s CEW exposure (n = 5), (3) 5-s CEW exposure with no chemical immobilisation (n = 10), (4) 15-s CEW exposure with no chemical immobilisation (n = 10) and (5) a control group with no chemical immobilisation or CEW exposure (n = 10). We conducted treatments 1 and 2 to determine short-term physiological effects of CEWs on deer, related to overall welfare. In treatment groups 1 and 2, we sedated deer to collect blood immediately before CEW exposure, and 2 days and 5 days post-exposure for serum biochemical analysis (to measure physiological markers of organ and tissue damage). We observed deer before, during and after treatments to evaluate potential behavioural changes. Key results All deer showed signs of muscle paralysis immediately after exposure to CEW and regained muscle control immediately after the exposure ended. Serum biochemistry results for treatment group 1 and 2 revealed significant increases in creatine kinase (CK) and aspartate aminotransferase (AST) 2 days post-treatment, before returning to pre-exposure concentrations by day 5-post-exposure, suggesting temporary myopathy. By 15-days post-exposure, deer that were only exposed to the CEW had 27 of 39 (69%) remotely fired probes still attached. No long-term behavioural or physiological changes were observed post-treatment. Conclusions Our findings suggest that for immobilisation of white-tailed deer, short-term exposure to a CEW to is a potential alternative to typical capture techniques and can provide sufficient immobilisation to approach and humanely kill deer by gunshot if necessary in wildlife emergencies. Implications As with all capture techniques, trainings and protocols should be developed to ensure the safety of personnel and animals during CEW exposures.

How do deer respiratory epithelial cells weather the initial storm of SARS-CoV-2 WA1/2020 strain?

The potential infectivity of severe acute respiratory syndrome associated coronavirus-2 (SARS-CoV-2) in animals raises a public health and economic concern, particularly the high susceptibility of white-tailed deer (WTD) to SARS-CoV-2. The disparity in the disease outcome between humans and WTD is very intriguing, as the latter are often asymptomatic, subclinical carriers of SARS-CoV-2. To date, no studies have evaluated the innate immune factors responsible for the contrasting SARS-CoV-2-associated disease outcomes in these mammalian species. A comparative transcriptomic analysis in primary respiratory epithelial cells of human (HRECs) and WTD (Deer-RECs) infected with the SARS-CoV-2 WA1/2020 strain was assessed throughout 48 h post inoculation (hpi). Both HRECs and Deer-RECs were susceptible to virus infection, with significantly (P < 0.001) lower virus replication in Deer-RECs. The number of differentially expressed genes (DEG) gradually increased in Deer-RECs but decreased in HRECs throughout the infection. The ingenuity pathway analysis of DEGs further identified that genes commonly altered during SARS-CoV-2 infection mainly belong to cytokine and chemokine response pathways mediated via interleukin-17 (IL-17) and nuclear factor-κB (NF-κB) signaling pathways. Inhibition of the NF-κB signaling in the Deer-RECs pathway was predicted as early as 6 hpi. The findings from this study could explain the lack of clinical signs reported in WTD in response to SARS-CoV-2 infection as opposed to the severe clinical outcomes reported in humans.IMPORTANCEThis study demonstrated that human and white-tailed deer primary respiratory epithelial cells are susceptible to the SARS-CoV-2 WA1/2020 strain infection. However, the comparative transcriptomic analysis revealed that deer cells could limit viral replication without causing hypercytokinemia by downregulating IL-17 and NF-κB signaling pathways. Identifying differentially expressed genes in human and deer cells that modulate key innate immunity pathways during the early infection will lead to developing targeted therapies toward preventing or mitigating the "cytokine storm" often associated with severe cases of coronavirus disease 19 (COVID-19). Moreover, results from this study will aid in identifying novel prognostic biomarkers in predicting SARS-CoV-2 adaption and transmission in deer and associated cervids.

Nasal bots carry relevant titers of CWD prions in naturally infected white-tailed deer.

Chronic wasting disease (CWD) is a prion disease affecting farmed and free-ranging cervids. CWD is rapidly expanding across North America and its mechanisms of transmission are not completely understood. Considering that cervids are commonly afflicted by nasal bot flies, we tested the potential of these parasites to transmit CWD. Parasites collected from naturally infected white-tailed deer were evaluated for their prion content using the protein misfolding cyclic amplification (PMCA) technology and bioassays. Here, we describe PMCA seeding activity in nasal bot larvae collected from naturally infected, nonclinical deer. These parasites efficiently infect CWD-susceptible mice in ways suggestive of high infectivity titers. To further mimic environmental transmission, bot larvae homogenates were mixed with soils, and plants were grown on them. We show that both soils and plants exposed to CWD-infected bot homogenates displayed seeding activity by PMCA. This is the first report describing prion infectivity in a naturally occurring deer parasite. Our data also demonstrate that CWD prions contained in nasal bots interact with environmental components and may be relevant for disease transmission.

Estimating landscape spread of a low‐prevalence disease using multiple surveillance methods

Abstract Diseases occurring at low prevalence in free‐ranging wildlife can be difficult to study and predict at a landscape scale. This problem is compounded by imperfect pathogen detection. We used data from multiple surveillance methods to determine factors influencing spread of a low‐prevalence disease, bovine tuberculosis (bTB), among white‐tailed deer (Odocoileus virginianus) in a bTB endemic area over a 10‐year period. We fit dynamic occupancy models to predict spatial spread of bTB through a county in Michigan, USA, within the bTB endemic area, while accounting for imperfect detection and a suite of ecological processes potentially driving bTB spread. Detection by all surveillance methods was low overall (posterior mean detection probabilities 0.01–0.03). Probability of bTB occurrence was 1.46 times as likely in the historical centre of the outbreak compared to outside. Deer density had a weakly positive effect on bTB spread. The probability of a site being newly infected with bTB annually was low (posterior mean colonization probabilities 0.08–0.27), while the probability of persistence after initial infection was high (posterior mean persistence probability 0.67). Synthesis and applications: We used three surveillance methods to estimate probability of presence and spread of a low‐prevalence pathogen at a landscape scale under incomplete sampling coverage. Our methods are relevant for determining spatial risk of any wildlife disease that is monitored using multiple methods of surveillance, which is important for prioritization of management actions.

A novel bluetongue virus serotype 2 strain isolated from a farmed Florida white-tailed deer (Odocoileus virginianus) arose from reassortment of gene segments derived from co-circulating serotypes in the Southeastern USA.

Bluetongue disease is a reportable animal disease that affects wild and farmed ruminants, including white-tailed deer (WTD). This report documents the clinical findings, ancillary diagnostics, and genomic characterization of a novel reassortant bluetongue virus serotype 2 (BTV-2) strain isolated from a dead Florida farmed WTD in 2022. Our analyses support that this BTV-2 strain likely stemmed from the acquisition of genome segments from co-circulating BTV strains in Florida and Louisiana. In addition, our analyses also indicate that genetically uncharacterized BTV strains may be circulating in the Southeastern USA; however, the identity and reassortant status of these BTV strains cannot be determined based on the VP2 and VP5 genome sequences. Hence, continued surveillance based on complete genome characterization is needed to understand the genetic diversity of BTV strains in this region and the potential threat they may pose to the health of deer and other ruminants.

Wildlife vaccination strategies for eliminating bovine tuberculosis in white-tailed deer populations.

Many pathogens of humans and livestock also infect wildlife that can act as a reservoir and challenge disease control or elimination. Efficient and effective prioritization of research and management actions requires an understanding of the potential for new tools to improve elimination probability with feasible deployment strategies that can be implemented at scale. Wildlife vaccination is gaining interest as a tool for managing several wildlife diseases. To evaluate the effect of vaccinating white-tailed deer (Odocoileus virginianus), in combination with harvest, in reducing and eliminating bovine tuberculosis from deer populations in Michigan, we developed a mechanistic age-structured disease transmission model for bovine tuberculosis with integrated disease management. We evaluated the impact of pulse vaccination across a range of vaccine properties. Pulse vaccination was effective for reducing disease prevalence rapidly with even low (30%) to moderate (60%) vaccine coverage of the susceptible and exposed deer population and was further improved when combined with increased harvest. The impact of increased harvest depended on the relative strength of transmission modes, i.e., direct vs indirect transmission. Vaccine coverage and efficacy were the most important vaccine properties for reducing and eliminating disease from the local population. By fitting the model to the core endemic area of bovine tuberculosis in Michigan, USA, we identified feasible integrated management strategies involving vaccination and increased harvest that reduced disease prevalence in free-ranging deer. Few scenarios led to disease elimination due to the chronic nature of bovine tuberculosis. A long-term commitment to regular vaccination campaigns, and further research on increasing vaccines efficacy and uptake rate in free-ranging deer are important for disease management.

PREGNANCY RATE AND NUMBER OF FETUSES OF WHITE-TAILED DEER RELATED TO BODY MEASUREMENTS AND SERUM METABOLITES

This study aimed to assess the association between fertility and the number of fetuses of free-ranging concentrate-supplemented white-tailed deer (Odocoileus virginianus, texanus, Mearns 1898) from northern Mexico (27 °N) with body measurements and serum metabolites indicative of nutritional status. We studied 119 female deer (31 yearlings and 88 adults) captured in January 2021 using a net gun fired from a helicopter. Ultrasound scanning showed 100 and 97.8 % pregnancy rate and 1.52 ± 0.51 and 1.50 ± 0.59 fetuses/pregnant doe for yearlings and adult does, respectively, with no difference (p &gt; 0.05) between age classes Thoracic circumference (cm) was higher (85.9 ± 4.9 vs. 84.1 ± 4.2; p = 0.039) for does carrying twins vs. singles. None of the serum metabolites indicative of nutritional status affected the fetal number of pregnant does. It was concluded that free-ranging white-tailed deer receiving concentrate supplementation in winter on a semi-arid rangeland has a high reproductive potential. Also, these results indicate that variation in maternal age within this population was not a significant driver of reproductive metrics of white-tailed deer. The plane of nutrition used in the present study was reflected in adequate serum metabolites indicative of nutritional status. Also, thoracic circumference may have prognostic value as a physical marker of multiple fetuses in female white-tailed deer.

Lack of detection of SARS-CoV-2 in wildlife from Kerala, India in 2020-21.

Spillover of SARS-CoV-2 into a variety of wild and domestic animals has been an ongoing feature of the human pandemic. The establishment of a new reservoir in white-tailed deer in North America and increasing divergence of the viruses circulating in them from those circulating in the human population has highlighted the ongoing risk this poses for global health. Some parts of the world have seen more intensive monitoring of wildlife species for SARS-CoV-2 and related coronaviruses but there are still very large gaps in geographical and species-specific information. This paper reports negative results for SARS-CoV-2 PCR based testing using a pan coronavirus end point RDRP PCR and a Sarbecovirus specific E gene qPCR on lung and or gut tissue from wildlife from the Indian State of Kerala. These animals included: 121 Rhinolophus rouxii (Rufous Horsehoe Bat), six Rhinolophus bedommei (Lesser Woolly Horseshoe Bat), 15 Rossettus leschenaultii (Fulvous Fruit Bat), 47 Macaca radiata (Bonnet macaques), 35 Paradoxurus hermaphroditus (Common Palm Civet), five Viverricula indica (Small Indian Civet), four Herpestes edwardsii (Common Mongoose), ten Panthera tigris (Bengal Tiger), eight Panthera pardus fusca (Indian Leopard), four Prionailurus bengalensis (Leopard cats), two Felis chaus (Jungle cats), two Cuon alpinus (Wild dogs) and one Melursus ursinus (sloth bear).

Regional differences in deer hunter attitudes and opinions regarding quality deer management (QDM)

ABSTRACT Quality deer management (QDM) is the preeminent framework by which white-tailed deer are managed in the eastern USA. Historic differences surrounding the cultures, traditions, and regulations of deer hunting exist regionally between the Midwest and Southeast, yet no published study has investigated regional differences in attitudes and opinions of QDM among deer hunters. We surveyed 9,301 deer hunters across two Midwestern states (Missouri and Ohio) and two Southeastern states (Louisiana and South Carolina) and found that hunters across regions held similar motivations for deer hunting, as well as similar attitudes and opinions of strategies and expected outcomes of QDM. However, there existed several mismatches between the practices and ideology associated with QDM among Southeastern hunters. Southeastern hunters held greater support for greater antlered bag limits, protection of does, and supplemental feeding. We postulate that these mismatches are largely driven by regional differences in cultures, traditions, and regulations surrounding deer hunting.

Losing the slow race: How deer hinder growth, survival, and regeneration of juvenile hemlocks (Tsuga canadensis)

White-tailed deer can limit both growth and survival in slow-growing, shade-tolerant tree species. We monitored 1,100 juvenile hemlocks (Tsuga canadensis) for up to 20 years at 54 sites in northern Wisconsin and Michigan to document causes of recruitment failure. These sites include public and private forestlands and First Nation reservations with distinct approaches to forest and wildlife management. We assessed deer impacts experimentally by protecting half of the juveniles from deer and observationally by tracking unprotected individuals at sites with various deer densities. We estimated local deer and hare presence and density using repeated pellet counts, which best predicted the survival and growth of juvenile hemlocks. Caged individuals out-survived unprotected ones (35.2 vs. 15.0y estimated half-lives). For the fastest-growing quartiles, transition times through the “molar zone” of vulnerability to deer browse (heights 5–200 cm) were 33.4 and 77.7y for protected vs. unprotected juveniles. Deer browsing strongly reduces both survival and growth, allowing us to compare estimates of these processes and their ratio among sites and cohorts. The “Regeneration Ratio” of half-life to growth averaged 1.06 for the top quartile of protected hemlock juveniles vs. 0.19 for juveniles exposed to deer. Ratios below 1.0 suggest risks to hemlock regeneration while values below 0.50 signal likely failure. Forest and wildlife managers must limit deer impacts if hemlock trees and stands are to remain viable components of the region’s forests.