White-tailed Deer Odocoileus Virginianus Research Articles

Transmission of SARS-CoV-2 in free-ranging white-tailed deer in the United States

SARS-CoV-2 is a zoonotic virus with documented bi-directional transmission between people and animals. Transmission of SARS-CoV-2 from humans to free-ranging white-tailed deer (Odocoileus virginianus) poses a unique public health risk due to the potential for reservoir establishment where variants may persist and evolve. We collected 8,830 respiratory samples from free-ranging white-tailed deer across Washington, D.C. and 26 states in the United States between November 2021 and April 2022. We obtained 391 sequences and identified 34 Pango lineages including the Alpha, Gamma, Delta, and Omicron variants. Evolutionary analyses showed these white-tailed deer viruses originated from at least 109 independent spillovers from humans, which resulted in 39 cases of subsequent local deer-to-deer transmission and three cases of potential spillover from white-tailed deer back to humans. Viruses repeatedly adapted to white-tailed deer with recurring amino acid substitutions across spike and other proteins. Overall, our findings suggest that multiple SARS-CoV-2 lineages were introduced, became enzootic, and co-circulated in white-tailed deer.

Rain, recreation and risk: Human activity and ecological disturbance create seasonal risk landscapes for the prey of an ambush predator.

Predation risk and prey responses exhibit fluctuations in space and time. Seasonal ecological disturbances can alter landscape structure and permeability to influence predator activity and efficacy, creating predictable patterns of risk for prey (seasonal risk landscapes). This may create corresponding seasonal shifts in antipredator behaviour, mediated by species ecology and trade-offs between risk and resources. Yet, how human recreation interacts with seasonal risk landscapes and antipredator behaviour remains understudied. In South Florida, we investigated the impact of a seasonal ecological disturbance, specifically flooding, which is inversely related to human activity, on interactions between Florida panthers (Puma concolor coryi) and white-tailed deer (Odocoileus virginianus). We hypothesized that human activity and ecological disturbances would interact with panther-deer ecology, resulting in the emergence of two distinct seasonal landscapes of predation risk and the corresponding antipredator responses. We conducted camera trap surveys across southwestern Florida to collect detection data on humans, panthers and deer. We analysed the influence of human site use and flooding on deer and panther detection probability, co-occurrence and diel activity during the flooded and dry seasons. Flooding led to decreased panther detections and increased deer detections, resulting in reduced deer-panther co-occurrence during the flooded season. Panthers exhibited increased nocturnality and reduced diel activity overlap with deer in areas with higher human activity. Supporting our hypothesis, panthers' avoidance of human recreation and flooding created distinct risk schedules for deer, driving their antipredator behaviour. Deer utilized flooded areas to spatially offset predation risk during the flooded season while increasing diurnal activity in response to human recreation during the dry season. We highlight the importance of understanding how competing risks and ecological disturbances influence predator and prey behaviour, leading to the generation of seasonal risk landscapes and antipredator responses. We emphasize the role of cyclical ecological disturbances in shaping dynamic predator-prey interactions. Furthermore, we highlight how human recreation may function as a 'temporal human shield,' altering seasonal risk landscapes and antipredator responses to reduce encounter rates between predators and prey.

Predicting and indexing ungulate browse intensity from local to regional scales

The intensity of browsing by white-tailed deer (Odocoileus virginianus; hereafter deer) can be influenced directly by deer densities and food availability, and indirectly by landscape characteristics that influence these factors. However, the variables and spatial scales that influence browsing intensity likely differ in landscapes with varying composition and land use. Furthermore, because high browsing intensity can influence the structure and function of forests, determining the most effective and efficient indices of browsing intensity can aid forest management decisions. To evaluate differences in browsing intensity, we used Bayesian hierarchical models to estimate the probability of browsing for twigs from non-avoided species based upon woodlot and landscape-scale variables, which were calculated within 200, 500, 1000, and 1500 m buffers. We then evaluated the efficacy of the twig age, oak sentinel, and herbaceous indicator methods of indexing browsing intensity by correlating these to browsing intensity and deer density. We also evaluated the expense and required work time associated with each index method. Food availability seemed to drive browsing intensities in our study, however, deer density was also important in the region with the lowest cover of forest. When meaningful, landscape characteristics fit data best at the 500 m buffer size. The twig age method showed the strongest correlations to both browsing intensity and deer density and was among the most efficient methods, suggesting it is a reliable index of browsing intensity within Indiana and similar regions. Together, our results highlight that landscape characteristics can mediate the relationship between deer and forest plant communities, which emphasizes the need to tailor management actions to variable landscapes that may occur within a single state or region. Additionally, our results suggest that the twig age method is the most efficient and effective index to monitor browse intensity in agriculturally dominated landscapes, such as those of the Central Hardwood Forest Region.

Quantifying the Influence of Emotions on Management Acceptability for White-Tailed Deer (Odocoileus virginianus)

Emotions pervade human-wildlife relationships across social identities and cultures. Yet research on how emotions influence the cognitive processing of wildlife encounters remains sparse. In this study, we quantify the role of anticipated emotions in processing hypothetical encounters with white-tailed deer (Odocoileus virginianus). In 2021, we surveyed Indiana residents about deer and deer management (n = 1.806). Under four hypothetical deer encounters, we estimated the structural relationships among respondents’ general attitudes toward deer, mutualism wildlife beliefs, scenario-specific emotions, and scenario-specific lethal control acceptability. Emotions mediated 14% of the effect of general attitudes on lethal control acceptability when encountering a fawn and completely mediated this effect when encountering a diseased deer. Our findings suggest that emotions work together with cognitions to process stimuli in a human-wildlife encounter and make a normative decision. Accounting for emotions in decision-making will help practitioners develop more effective and socially accepted approaches to wildlife conservation and management.

Fusion of visible and thermal images improves automated detection and classification of animals for drone surveys

Visible and thermal images acquired from drones (unoccupied aircraft systems) have substantially improved animal monitoring. Combining complementary information from both image types provides a powerful approach for automating detection and classification of multiple animal species to augment drone surveys. We compared eight image fusion methods using thermal and visible drone images combined with two supervised deep learning models, to evaluate the detection and classification of white-tailed deer (Odocoileus virginianus), domestic cow (Bos taurus), and domestic horse (Equus caballus). We classified visible and thermal images separately and compared them with the results of image fusion. Fused images provided minimal improvement for cows and horses compared to visible images alone, likely because the size, shape, and color of these species made them conspicuous against the background. For white-tailed deer, which were typically cryptic against their backgrounds and often in shadows in visible images, the added information from thermal images improved detection and classification in fusion methods from 15 to 85%. Our results suggest that image fusion is ideal for surveying animals inconspicuous from their backgrounds, and our approach uses few image pairs to train compared to typical machine-learning methods. We discuss computational and field considerations to improve drone surveys using our fusion approach.

Partial cutting favours northern white-cedar regeneration but does not ensure recruitment to canopy: does browsing matter?

Abstract Gap dynamics facilitate recruitment of late-successional species such as northern white-cedar (Thuja occidentalis L.). For this reason, harvests that result in partial rather than complete canopy removal have been suggested for cedar. However, success of regenerating cedar following partial harvests is uncertain, especially where there is heavy browsing by white-tailed deer (Odocoileus virginianus Zimmerman) or snowshoe hare (Lepus americanus). Efforts to understand how partial harvests and browsing interact to affect natural regeneration of cedar have been limited. We inventoried partially harvested stands along a gradient of 1–11 years since harvest in New Brunswick, Canada, in an area where deer frequently overwinter. Cedar regeneration was negatively influenced by browsing, but positively influenced by years since harvest and sapling basal area. Cedar seedling survival was assessed over a 2-year period and found to be primarily a function of height at initial measurement, with little influence of browsing. Annual vertical gain of cedar seedlings (a surrogate for height growth) decreased with increasing years since harvest and was influenced by distance from gap edge. In gaps, vertical gain increased with distance to gap edge, while distance to gap edge had a negative influence on vertical gain of seedlings in the matrix (between-gap areas). Many tagged cedar seedlings disappeared prior to remeasurement. These were likely completely consumed by browsers, limiting our ability to determine relative influences of partial harvest and browsing on cedar regeneration. We conclude that partial harvests, as applied in this study, increase cedar abundance and vertical gain, but browsing may necessitate seedling protection. We suggest monitoring to confirm sufficient cedar regeneration in partially harvested stands, using exclosures where browsing is a concern, and retaining or at least delaying removal of seed-bearing cedar overstory trees until regeneration has reached heights safe from browsing.

Economic returns and the perceived obstacles to adopting active management in the forest-grassland transition ecoregion in south-central USA

Forest-grassland ecotones are a mosaic of grassland, savanna, and upland forest. As such, landowners may have opportunities to choose to manage their lands for multiple objectives. We estimated the economic returns from managing forest and rangeland in southeastern Oklahoma, USA to produce different combinations of timber, cattle forage, and white-tailed deer (Odocoileus virginianus Zimmermann) browse for a 40-year period. We further conducted a survey to understand landowner perceptions of obstacles to adopting active management that involve timber harvest and prescribed fire. The highest net return was obtained from the treatment with harvested timber that was burned every four years (uneven-aged woodland/forest) because it had the greatest gross return from a combination of timber (46%), cattle forage (42%), and deer browse (11%). The return from this treatment was greater than that for managed for timber only (closed-canopy forest) or prioritizing cattle and deer (savanna). Survey results suggested that landowners were aware of the benefits of active management but that the majority (66%) considered cost a major obstacle in the management of their forest or rangeland. In particular, women forestland owners and older landowners considered cost an obstacle. Our findings advocate integrated timber, cattle, and deer management as the best economic strategy within the forest-grassland ecotone and for targeted outreach and landowner education related to the benefits of active management.

Influence of Aboveground Pipeline and Associated Factors on Movement of Winter-Active Boreal Mammals in the Alberta In-Situ Oil Sands

Aboveground pipelines (AGP) associated with in-situ oil sands may restrict mammal movement, potentially increasing extinction probability and decreasing reproductive success. Our 12-year study used winter track count techniques to assess the response of winter-active mammals to AGP in northern Alberta, Canada. The primary questions were: which species were most prone to movement obstruction by AGP, facilities or natural factor(s)?; and which factor exerted the strongest influence on crossing likelihood? A total of 2,068 trails of 12 different species were observed. All species crossed more than half of the time. Focal species crossed on average 80% of the time. Crossing likelihood of white-tailed deer (Odocoileus virginianus), ermine (Mustela erminea), coyote (Canis latrans), lynx (Lynx canadensis), and fisher (Martes pennanti) were significantly influenced by predictors including pipeline height, pipeline corridor width, infrastructure age, vegetation type, and proximity to infrastructure. Deer and lynx crossing likelihood was positively affected by pipe height. Deer, coyote, and ermine crossing likelihood was positively affected by age of pipe. Fisher and deer crossing likelihood was negatively affected by pipeline corridor widths. Our investigations show that most species cross AGP with high crossing frequencies of pipe heights, ranging from 130 cm to 160 cm. These findings are important for impact mitigation because of the scarcity of published studies of wildlife movement responses to AGP, our inclusion of small and mid-sized carnivores, and our investigation of multiple factors. We highlight mitigation and design improvements, effects of pipeline corridor widths, and challenges posed by coupling infrastructure with pipelines, serving to reduce movement barriers and fragmentation.

Ticks harbor and excrete chronic wasting disease prions

Chronic wasting disease (CWD) is a fatal neurodegenerative disease caused by infectious prions (PrPCWD) affecting cervids. Circulating PrPCWD in blood may pose a risk for indirect transmission by way of hematophagous ectoparasites acting as mechanical vectors. Cervids can carry high tick infestations and exhibit allogrooming, a common tick defense strategy between conspecifics. Ingestion of ticks during allogrooming may expose naïve animals to CWD, if ticks harbor PrPCWD. This study investigates whether ticks can harbor transmission-relevant quantities of PrPCWD by combining experimental tick feeding trials and evaluation of ticks from free-ranging white-tailed deer (Odocoileus virginianus). Using the real-time quaking-induced conversion (RT-QuIC) assay, we show that black-legged ticks (Ixodes scapularis) fed PrPCWD-spiked blood using artificial membranes ingest and excrete PrPCWD. Combining results of RT-QuIC and protein misfolding cyclic amplification, we detected seeding activity from 6 of 15 (40%) pooled tick samples collected from wild CWD-infected white-tailed deer. Seeding activities in ticks were analogous to 10–1000 ng of CWD-positive retropharyngeal lymph node collected from deer upon which they were feeding. Estimates revealed a median infectious dose range of 0.3–42.4 per tick, suggesting that ticks can take up transmission-relevant amounts of PrPCWD and may pose a CWD risk to cervids.

Cover Image

EcosphereVolume 14, Issue 5 e4123 COVER IMAGEOpen Access Cover Image First published: 07 May 2023 https://doi.org/10.1002/ecs2.4123AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract COVER PHOTO: To understand how environmental variables influence white-tailed deer (Odocoileus virginianus) fawn survival, Engebretsen et al. (“Noninvasive camera data and spatial capture–recapture models reveal strong temporal variation in fawn survival,” Ecosphere, Volume 14, Issue 4, Article e4497; doi: 10.1002/ecs2.4497) deployed 180 cameras throughout the Florida Panther National Wildlife Refuge and the Big Cypress National Preserve. The authors were able to identify 271 fawns, such as the one shown here traveling with its mother through a cypress dome in the Big Cypress National Preserve. They used the camera data to create a dataset for a spatial capture–recapture analysis that revealed differences in survival to 180 days between fawns born in 2015 and those born in 2016. Their data suggest that extreme weather events likely contributed to lower recruitment in south Florida, USA. Photo credit: the authors. Volume14, Issue5May 2023e4123 RelatedInformation

Evaluating the fidelity of enamel isotopic data and environmental variation in paleoecological studies: A case study in wild, known-aged, modern white-tailed deer (Odocoileus virginianus)

Stable carbon and oxygen isotope variability in herbivore enamel is frequently used to evaluate seasonal changes in the diets of fossil taxa as well as their broader ecosystems. Unfortunately, these reconstructions are often based on small samples (i.e., < 5 individuals) and the impacts of inter- and intraindividual variation on these data are largely unknown due to the lack of a modern comparative framework from wild herbivore populations. In this study, we used serially-sampled isotope values from the mandibular dentition (M1, M2, M3) of five wild, male white-tailed deer (Odocoileus virginianus) with known life histories from the Piedmont National Wildlife Refuge (PNWR; central Georgia, USA), to test the fidelity to which seasonal ecosystem-level variability is reflected in enamel carbon and oxygen isotope values. δ13C values across all individuals and sampled teeth fell within −21‰ and − 15.8‰, thereby indicating a diet dominated by C3 vegetation throughout the spring, summer, fall and winter months. We find significant (p < 0.05) inter-individual differences in the means of M1, M2 and M3δ13C and δ18O values, with the exception of M2δ18O values. M1δ13C values were consistently depleted, while δ18O values were consistently enriched (relative to M2 and M3) across all individuals sampled, likely indicative of pre-weaning, milk-dominated diet. Finally, there was little change in δ18O values across the M1, M2 and M3 despite dramatic fluctuations in temperature at the PNWR. We hypothesize that the primary driver of this pattern is the depletion of M2δ18O values due to the amount effect. These data support a complex relationship between enamel isotopic variation and the fluctuation of abiotic and biotic ecosystem variables that should be more fully considered in paleoecological analyses.

Forage quantity and protein concentration changes across a forest-savanna gradient with management implications for white-tailed deer

White-tailed deer (Odocoileus virginianus) hunting is an important economic activity associated with the management of forests and rangelands in the USA, with over $12.9 billion dollars of related annual expenditures. Reducing tree cover through thinning and prescribed fire both have the potential to increase the quantity and quality of deer forage. We evaluated the long-term impacts of eight different combinations of fire return intervals and tree harvest on forage productivity and protein content of the forage. Based on management regime, study units ranged from savanna to closed-canopy forest. Aboveground net primary production (ANPP) of six functional groups (grass, panicum, forb, legume, woody, sedge) of understory vegetation was measured in October 2019 and 2020 using destructive sampling. Samples for foliar crude protein (CP) concentration were collected in spring, summer, and fall of 2020. Total understory ANPP ranged from 2.9 to 466.3 g m−2 and was up to 566% greater in savanna systems maintained by frequent fire (return interval of three years or less) than in non-burned forest treatments. Annual burning resulted in ANPP dominated by herbaceous plants composed mostly of fire-tolerant grasses (e.g., Andropogon gerardii, Schizachyrium scoparium). Longer fire return intervals or no fire resulted in roughly equal ANPP from understory woody and herbaceous species. Crude protein concentrations were up to 45.7% greater in the woodland and forest units than in the savanna units for seven of the eleven species sampled. The greater CP in the forests was most noticeable in the summer when deer needs for quality forage are substantial. Increased protein concentrations of understory species in the forests, but greater ANPP in the savannas indicate that managing for a mix of savanna and woodland could be ideal for balancing forage quantity with increased forage protein.

Vitrification of White-tailed Deer (Odocoileus virginianus) oocytes with sucrose or trehalose for in vitro maturation and fertilization.

Objective: Evaluate the White-tailed Deer (WTD) in vitro embryo production (IVP) and oocytes vitrified with Trehalose (TH) or Sucrose (SC).&#x0D; Design/methodology/approach: Total vitrified oocytes were placed into two different groups: TH (n=60) and SC (n=61). Samples were selected and analyzed for viability evaluation TH (n=5) and SC (n=5), nuclear status (NS) TH (n=4) and SC (n=5), Germinal Vesicle (GV), Metaphase I, or not evaluable (NE) after warming. In vitro maturation (IVM) was conducted for 36 h in supplemented TCM-199 medium. Immediately afterwards, oocyte NS was evaluated (n=88) [(GV, MI=immature), (MII=mature)]. In vitro fertilization (IVF) was performed in supplemented TALP medium for 24 h using frozen WTD semen (3x106 sperm/mL), NS was classified [Fertilized (F), Not fertilized (NF), or NE].&#x0D; Results: After warming, viability for the TH group (n=5) was 60% versus 40% for SC group (n=5), however, oocytes in both groups were immature (GV and MI stage). For IVM, NS evaluations of the TH group (n=38) revealed no maturation versus 2% in the SC group (n=50) (MII stage=matured). IVF evaluations for the TH group (n=10) revealed no fertilization compared to 20% in the SC group (n=5). A statistical difference (p&gt;0.05) was not found between the TH and SC groups.&#x0D; Limitations on study/implications: White-tailed Deer in vitro embryo production is not well documented.&#x0D; Findings/conclusions: Future research with a larger number of WTD oocytes is needed for further evaluation of oocyte vitrification IVP techniques as a model for endangered cervids.

Selection rankings of woody species for white-tailed deer vary with browse intensity and landscape context within the Central Hardwood Forest Region

White-tailed deer (Odocoileus virginianus) selection of woody species can be influenced by deer densities, food availability, and local and regional landscape characteristics. Determining selection rankings across varying regional landscapes is important to the management of both deer and forests. However, these regional-scale rankings are currently lacking. Here, we develop selection rankings for 63 species within woodlots across the southern, central, and northern regions of Indiana by counting the number of available and browsed twigs by species along transects. We then classified species into five selection classes: highly selected, slightly selected, neutral, slightly avoided, and strongly avoided. Some species displayed consistent classification across regions, including selection for greenbrier (Smilax spp.), hackberry (Celtis occidentalis), white ash (Fraxinus americana), and white oak (Quercus alba) and avoidance of spicebush (Lindera benzoin) and pawpaw (Asimina triloba). For the 16 species that exhibited significant regional variation in selection, we modeled the probability of a twig being browsed using explanatory variables measured at the woodlot scale, and within 200, 500, 1000, and 1500 m buffers around woodlots. Browsing intensity within a focal woodlot was more often associated with increased selection of an individual species than other explanatory variables. Nonetheless, both woodlot and landscape-scale variables influenced selection of woody browse by deer. In general, factors that increased browsing opportunities (e.g., increased density of non-avoided twigs, increased forest edge density, and increased woodlot edge) increased the selection of an individual species, while those that decreased browsing opportunities (e.g., increased non-native stem density and increased avoided twig density) decreased selection. Our selection classifications for common species in the Central Hardwood Forest Region highlight species that may be at risk of being negatively affected by severe browsing, while simultaneously identifying species that decrease foraging habitat quality. Our results also provide evidence that local and regional conditions drive differences in selection; and thus, require evaluation prior to management. More broadly, we showcase that multiple variables and spatial scales can affect selection of individual browse species by deer and merit consideration by researchers when studying the effects of browsing on forest ecosystems.

Inter-annual prey fluctuation of Odocoileus virginianus in Maya group hunting (batida) in the Yucatan Peninsula

In Neotropical environments, we know little about the abundance of wild vertebrates traditionally hunted. Based on subsistencehunting records (2005-2019) as well as ethnographic information from Maya peasant-hunters, we assessed the inter-annual capture rate of white-tailed deer (Odocoileus virginianus) in a rural community in the northwest of the Yucatan Peninsula. We found that the number of prey decreased over the years, showing a declining capture rate (prey/trip) that decreased by as much as 50% from the first (2005-2006) to the third period (2010-2011) of records. The majority of peasant-hunters interviewed (74%; N = 31) perceived this reduction in deer to have taken place mainly over the past 10 years as consequence of hunting (71%). The agreement between the hunting trend and peasants’ perceptions regarding the abundance of white-tailed deersuggests that this species may be at risk in future scenarios of use in northwest of contemporary Mayab.

Tonsil biopsy to detect chronic wasting disease in white-tailed deer (Odocoileus virginianus) by immunohistochemistry.

Chronic wasting disease (CWD) continues to spread in wild and farmed cervid populations. Early antemortem CWD testing of farmed cervids is of considerable interest to producers and regulatory agencies as a tool to combat this spread. The tissues accessible for antemortem sampling are limited and include biopsy of the tonsil and recto-anal mucosa-associated lymphoid tissue (RAMALT). The sensitivity to detect CWD by immunohistochemistry (IHC)-the regulatory gold standard-using biopsy samples of RAMALT from naturally infected white-tailed deer (WTD) has been determined by several studies. However, similar information is lacking for tonsil biopsy. In this study, two-bite tonsil biopsies from 79 naturally infected farmed WTD were used to determine the diagnostic sensitivity of tonsil IHC compared to the official CWD status based on results from the medial retropharyngeal lymph nodes and obex. IHC detection of CWD by tonsil biopsy was compared to the result and follicle metrics from the contralateral whole tonsil. The sensitivity of two-bite tonsil biopsy for detecting CWD by IHC was 72% overall. When the stage of infection was considered, the sensitivity was 92% for deer in late preclinical infection but only 55% for early preclinical infection. For deer with early preclinical infection, the sensitivity for deer homozygous for the prion protein gene (PRNP) coding for glycine at codon 96 (GG) was 66% but only 30% when heterozygous for the serine substitution (GS). The results indicate that the sensitivity of two-bite tonsil biopsy in WTD, and consequently its potential utility as an antemortem diagnostic, is limited during early infection, especially in WTD heterozygous for the serine substitution at PRNP codon 96.

Understanding Habitats and Environmental Conditions of White-Tailed Deer Population Density and Public Health Data to Aid in Assessing Human Tick-Borne Disease Risk.

The extent of tick-borne diseases (TBDs) in the United States is largely unknown and underreported. Equitable diagnostic and treatment options may vary by geographic location. Triangulating multi-modal data sources informed by a One Health approach provides robust proxies for human TBD risk. Using data from the Indiana Department of Natural Resources collected from hunters during the white-tailed deer (Odocoileus virginianus) hunting season and other sources, we employ a mixed-methods approach based on thematic mapping and mixed effects modelling to determine if deer population density aligns with official disease data at the county level from (1) positive canine serological reports for, anaplasmosis, and Lyme Disease (LD); (2) positive human cases of ehrlichiosis, anaplasmosis, LD, and Spotted Fever rickettsioses; and (3) tick infectivity. We propose the need for multimodal data analysis using a variety of potential proxies to better estimate disease risk and inform public health policy and practice. We find similar spatial distributions between deer population density and human and canine TBDs in northeastern and southern Indiana, which are rural and mixed geographic areas. Overall, LD is more prevalent in the northwest, central-western, and southeastern counties, while ehrlichiosis is more common in the southern counties. These findings hold true across humans, canines, and deer.

Intentions of Landowners towards Active Management of Ecosystem for Deer Habitat.

Active management such as prescribed fire and thinning can restore savanna and prairie ecosystem to maintain a full suite of ecosystem services and create suitable habitat for wildlife species such as white-tailed deer (Odocoileus virginianus). Active management comes with the cost of management and acceptance of management tools. The south-central transitional ecoregion of the USA, which otherwise was a mixture of forest, savanna, and tallgrass prairie, is increasing in woody plant dominance due to the exclusion of fire and other anthropogenic factors. Deer hunting is a vital source of revenue generation to offset the landowner's management cost in the region. We studied Oklahoma landowners' perceptions regarding active and sustainable management of forest and rangeland for deer habitat using two established theories of reasoned action and planned behavior as well as expanded theories adding moral norms. We analyzed mailed survey data using structural equation modeling. We found that subjective norms and perceived behavior control significantly affected deer hunting intention when moral norms were introduced into the model. Attitudes independently significantly affected intentions of deer hunting but have negative relations with the intentions. The study suggested that landowners have positive social pressure and were interested in active management but associated financial burden and risk could be shaping negative attitudes.

Impact of white-tailed deer on northern white cedar recruitment beyond the browsing vulnerability zone: A broad-scale study

By selectively feeding on the new vegetation from forest regeneration, cervids influence the abundance of understory species. This can lead to recruitment failure for the consumed species. The impact of cervids on regeneration is generally studied at fine scales, making it difficult to generalize about the species distribution scale for co-occurring cervid and tree species. This is especially problematic for species such as northern white cedar (Thuja occidentalis L.), which is susceptible to browsing and has been declining throughout much of its range. In our study, we aimed to determine the effect of the spatio-temporal variations in white-tailed deer (Odocoileus virginianus Zimmerman) abundance on northern white cedar recruitment over a broad spatial scale. We combined distinct forest and wildlife monitoring databases for two Canadian provinces, Québec and New Brunswick. We also surveyed cedar regeneration and deer browsing pressure in a subset of plots located in Québec. In both provinces, we detected a negative effect of deer abundance and deeryard proximity on the recruitment of cedar saplings. In Québec, local deer browsing pressure also had a negative effect on cedar seedling abundance. As deer browsing pressure can vary considerably over a short distance, we recommend the inclusion of browsing indicators in national forest surveys to precisely assess the impact of browsing on regeneration and recruitment. This would allow managers to identify areas that are highly vulnerable to browsing and adapt forest management accordingly to reduce browsing-induced regeneration failures.

Herbaceous plant height is an early indicator of groundlayer response to an experimental manipulation of forest structure and deer pressure

There is growing interest in adapting forest management to increase diversity, in both composition and structure, to restore old-growth characteristics and to build resiliency against anthropogenic disturbances. In order to determine appropriate interventions, managers need to evaluate the quality of natural areas but efficient and effective measurements are elusive. Using a suite of herbaceous species and measuring their responses to experimental treatments, we aim to assess (1) the sensitivity of different metrics and (2) the current and likely future effects of gap-generating disturbances and abundant deer on the understory of a northern hardwood forest in Wisconsin, USA. More specifically, we investigated plant cover, density, height, aggregate height and the proportion of individuals producing flowers/fruits under unmanipulated canopies v. three gap sizes, with and without downed woody material (DWM) additions, and inside v. outside of white-tailed deer (Odocoileus virginianus) exclusion fences, approximately seven years after treatment. The effects were taxon-specific with Anemone quinquefolia, Arisaema triphyllum, Laportea canadensis and Trillium grandiflorum being most responsive to canopy structure, Impatiens spp. and T. grandiflorum to deer pressure, and A. triphyllum, Impatiens spp., L. canadensis and Sanguinaria canadensis to canopy structure in combination with DWM. Cover was least responsive to treatments, density and proportion of sexually reproducing individuals sometimes differed, but height was overall the best metric. Mean height and maximum height showed similar results so we suggest that managers focus on measuring maximum height to limit sampling time. We also draw attention to the importance of retaining and/or creating DWM which has long been recognized as an important structural feature promoting diversity in natural forests. In the present study, DWM additions appeared to play a role in mitigating microclimates and/or deer pressure for multiple herbaceous species.