Abundance Of White-tailed Deer Research Articles

A model-based estimate of winter distribution and abundance of white-tailed deer in the Adirondack Park.

In the Adirondack Park region of northern New York, USA, white-tailed deer (Odocoileus virginianus) and moose (Alces alces) co-occur along a temperate-boreal forest ecotone. In this region, moose exist as a small and vulnerable low-density population and over-browsing by white-tailed deer is known to reduce regeneration, sustainability, and health of forests. Here, we assess the distribution and abundance of white-tailed deer at a broad spatial scale relevant for deer and moose management in northern New York. We used density surface modeling (DSM) under a conventional distance sampling framework, tied to a winter aerial survey, to create a spatially explicit estimate of white-tailed deer abundance and density across a vast, northern forest region. We estimated 16,352 white-tailed deer (95% CI 11,762–22,734) throughout the Adirondack Park with local density ranging between 0.00–5.73 deer/km2. Most of the Adirondack Park (91.2%) supported white-tailed deer densities of ≤2 individuals/km2. White-tailed deer density increased with increasing proximity to anthropogenic land cover such as timber cuts, roads, and agriculture and decreased in areas with increasing elevation and days with snow cover. We conclude that climate change will be more favorable for white-tailed deer than for moose because milder winters and increased growing seasons will likely have a pronounced influence on deer abundance and distribution across the Adirondack Park. Therefore, identifying specific environmental conditions facilitating the expansion of white-tailed deer into areas with low-density moose populations can assist managers in anticipating potential changes in ungulate distribution and abundance and to develop appropriate management actions to mitigate negative consequences such as disease spread and increased competition for limiting resources.

Tick-borne disease risk in a forest food web.

Changes to the community ecology of hosts for zoonotic pathogens, particularly rodents, are likely to influence the emergence and prevalence of zoonotic diseases worldwide. However, the complex interactions between abiotic factors, pathogens, vectors, hosts, and both food resources and predators of hosts are difficult to disentangle. Here we (1) use 19yr of data from six large field plots in southeastern New York to compare the effects of hypothesized drivers of interannual variation in Lyme disease risk, including the abundance of acorns, rodents, and deer, as well as a series of climate variables; and (2) employ landscape epidemiology to explore how variation in predator community structure and forest cover influences spatial variation in the infection prevalence of ticks for the Lyme disease bacterium, Borrelia burgdorferi, and two other important tick-borne pathogens, Anaplasma phagocytophilum and Babesia microti. Acorn-driven increases in the abundance of mice were correlated with a lagged increase in the abundance of questing nymph-stage Ixodes scapularis ticks infected with Lyme disease bacteria. Abundance of white-tailed deer 2 yr prior also correlated with increased density of infected nymphal ticks, although the effect was weak. Density of rodents in the current year was a strong negative predictor of nymph density, apparently because high current abundance of these hosts can remove nymphs from the host-seeking population. Warm, dry spring or winter weather was associated with reduced density of infected nymphs. At the landscape scale, the presence of functionally diverse predator communities or of bobcats, the only obligate carnivore, was associated with reduced infection prevalence of I.scapularis nymphs with all three zoonotic pathogens. In the case of Lyme disease, infection prevalence increased where coyotes were present but smaller predators were displaced or otherwise absent. For all pathogens, infection prevalence was lowest when forest cover within a 1km radius was high. Taken together, our results suggest that a food web perspective including bottom-up and top-down forcing is needed to understand drivers of tick-borne disease risk, a result that may also apply to other rodent-borne zoonoses. Prevention of exposure based on ecological indicators of heightened risk should help protect public health.

Motorized Activity on Legacy Seismic Lines: A Predictive Modeling Approach to Prioritize Restoration Efforts.

Natural regeneration of seismic lines, cleared for hydrocarbon exploration, is slow and often hindered by vegetation damage, soil compaction, and motorized human activity. There is an extensive network of seismic lines in western Canada which is known to impact forest ecosystems, and seismic lines have been linked to declines in woodland caribou (Rangifer tarandus caribou). Seismic line restoration is costly, but necessary for caribou conservation to reduce cumulative disturbance. Understanding where motorized activity may be impeding regeneration of seismic lines will aid in prioritizing restoration. Our study area in west-central Alberta, encompassed five caribou ranges where restoration is required under federal species at risk recovery strategies, hence prioritizing seismic lines for restoration is of immediate conservation value. To understand patterns of motorized activity on seismic lines, we evaluated five a priori hypotheses using a predictive modeling framework and Geographic Information System variables across three landscapes in the foothills and northern boreal regions of Alberta. In the northern boreal landscape, motorized activity was most common in dry areas with a large industrial footprint. In highly disturbed areas of the foothills, motorized activity on seismic lines increased with low vegetation heights, relatively dry soils, and further from forest cutblocks, while in less disturbed areas of the foothills, motorized activity on seismic lines decreased proportional to seismic line density, slope steepness, and white-tailed deer abundance, and increased proportional with distance to roads. We generated predictive maps of high motorized activity, identifying 21,777 km of seismic lines where active restoration could expedite forest regeneration.

Interactions between white-tailed deer density and the composition of forest understories in the northern United States

Forest understories across the northern United States (US) are a complex of tree seedlings, endemic forbs, herbs, shrubs, and introduced plant species within a forest structure defined by tree and forest floor attributes. The substantial increase in white-tailed deer (Odocoileus virginianus Zimmerman) populations over the past decades has resulted in heavy browse pressure in many of these forests. To gain an objective assessment of the role of deer in forested ecosystems, a region-wide forest inventory across the northern US was examined in concert with white-tailed deer density information compiled at broad scales. Results indicate that deer density may be an additional driver of tree seedling abundance when analyzed along with stand attributes such as aboveground biomass, relative density, and stand age. Tree seedling abundance generally decreased as deer density increased above 5.8deerkm2 for all forest type groups with the exception of oak-dominated forests. Findings indicate that introduced plant species, of which 393 were recorded in this study, increased in areas with higher deer density. The abundance of white-tailed deer is just as important as forest stand and site attributes in the development of forest understories. Given the complexity of forest and land use dynamics across the northern US, this study provides directions for future research as more data linking forest-dependent wildlife and forest dynamics at regional and national scales become available.

Scale-Dependent Effects of Coyote-Predation Risk on Patterns of White-Tailed Deer Browsing along Linear Forest Edges

Abstract Browsing by Odocoileus virginianus (White-tailed Deer) plays an important role in shaping forest structure in the northeastern US. Predation can influence patterns of browse through decreasing White-tailed Deer abundance and influencing patterns of habitat selection. Canis latrans (Coyote) is the dominant predator of White-tailed Deer in our focal region in northern New York. Optimal foraging theory suggests that White-tailed Deer browse in locations that maximize energy intake while minimizing predation risk. Linear forest edges provide abundant woody browse for White-tailed Deer, but are also used as travel-ways by Coyotes in our focal region. These locations therefore provide a venue for testing the extent to which predation risk influences patterns of White-tailed Deer browsing. We quantified White-tailed Deer browse use for edge and interior sites and the density of Coyote scats along seventeen 500-m transects to evaluate the scale at which White-tailed Deer herbivory was affected by Coyote ...

Impact on plant communities by white-tailed deer in Mississippi, USA

Background: The abundance of white-tailed deer (Odocoileus virginianus) in the eastern United States has escalated during the twentieth century, potentially impacting plant communities.Methods: We measured understorey plant cover and biomass five years after excluding deer from mature forests of three ecological regions in Mississippi, USA. We extended the significance of P values to 0.10 to detect developing impacts.Results: Deer impacts were limited and varied by ecological region. We recorded 151 species in cover transects. Consistent exclosure treatment effects were detected in two regions where there was greater cover of two deer forages and less cover of three non-forages. Species richness was greater in exclosures in one region, but otherwise species richness and diversity indices did not differ. We recorded 127 species in biomass quadrats. Exclosure treatment effects on biomass were inconsistent. Out of five species with significant differences, three had more biomass in controls, including two deer forages. Except for greater total biomass in controls of one region, there were no differences by growth form or total vegetation for canopy coverage or biomass. Ordination of community canopy cover demonstrated similarity of paired exclosure and controls.Conclusions: Exclosure treatment effects on canopy cover and species richness in two regions indicated limited negative impacts from deer foraging. A time frame of more than five years may be required for exclusion to allow recovery of vegetation, even with relatively open canopies and a long growing season.

Effect of paved road density on abundance of white-tailed deer

Context Although ~3% of white-tailed deer are killed on roads each year, no previous study has tested for an effect of roads on deer abundance. This is difficult to do because road density is generally negatively correlated with deer habitat availability. Aims Our goal was to determine whether roads affect deer abundance. Methods First, we used an existing dataset from Pennsylvania, USA, to determine a range of paved road densities representing a significant range in deer per capita mortality. We then conducted a field study in eastern Ontario, Canada, with sample sites for relative deer abundance selected such that (1) road density in the surrounding landscapes varied over this same range, and (2) there were low correlations across landscapes between road density and deer habitat availability. The latter allowed us to isolate the effects of roads from the effects of habitat on deer abundance. We indexed relative deer abundance using a combination of pellet samples and track counts. Key results Unexpectedly, we observed a positive relationship between relative deer abundance and paved road density. Conclusions We speculate that this positive relationship is due to (1) reduced deer predation and/or perceived predation risk and/or hunting pressure in landscapes with higher road density and/or (2) provision of a resource or service by roads, the benefits of which outweigh the road mortality. Implications We found no evidence that road mortality places deer populations at risk of decline, at least over the range of road density values in our study. Therefore we conclude that road mortality is not a conservation concern for white-tailed deer in ecological contexts similar to our study areas.

Regulated Commercial Harvest to Manage Overabundant White-Tailed Deer: An Idea to Consider?

Author(s): VerCauteren, Kurt C.; Anderson, Charles W.; Van Deelen, Timothy R.; Drake, David; Walter, W. David; Vantassel, Stephen M.; Hygnstrom, Scott E. | Abstract: Declines in hunter recruitment coupled with dramatic growth in numbers of white-tailed deer (Odocoileus virginianus) have challenged our ability to manage deer populations through traditional methods. We surveyed all state wildlife agencies and estimate the abundance of white-tailed deer in North America currently exceeds 30 million. Traditional methods of population management have been ineffective in reducing numbers of deer sufficiently in some environments. The only way to manage overabundant deer directly, cost-effectively, and in a timely fashion is through lethal methods. States currently are issuing record numbers of permits to hunters to increase harvest of white-tailed deer. Unfortunately, hunter participation has been declining in North America during the past two decades. Regulated commercial harvest would help state wildlife agencies manage overabundant populations of white-tailed deer andallow hunters to sell all orparts of harvested deer. We anticipate that many will criticize regulated commercial harvest of deer and claim that it is contrary to the North American Model of Wildlife Conservation (NAMWC). We can, however,argue that regulated commercial harvest meets all seven of the pillars of the NAMWC: 1) Wildlife is a natural resource of the public trust(state wildlife agencies willmanage deeranddeerwould continue to be a public resource). 2) No commercial use of wildlife [a direct reaction to exploitive and unsustainable market hunting in the 18th and 19th Centuries; commercial markets currently exist for other natural resources (e.g., furbearers, fish, timber); contemporary conservation values would not allow overexploitation; a framework for regulations, monitoring, and enforcement already isin place in every state]. 3) Democratic rule of law to regulate use of wildlife (commercial harvest of white-tailed deer would be highly regulated by wildlife agencies through public processes). 4) Hunting opportunity for all (anyone legally able to hold a deer hunting license would be eligible to apply for a Commercial Deer Harvest License (CDHL), CDHL programs would be implemented only where recreational hunting is proven inefficient or inappropriate). 5) No frivolous use of wildlife (CDHLs will beused to generate of food and other products, management would address risk to human health and safety andlosses ofagricultural resourcesto deer). 6) Wildlife is an international resource (has little to do with our proposed idea of managing overabundant resident populations of white-tailed deer, but a CDHL program may be applicable to any overabundant species, including internationally migratory species,such assnow geese,Chen caerulescens). 7) Science-based wildlife policy (a CDHL program would rely on science and research-based data to estimate densities before, during, and after commercial harvest). A CDHL program should be managed and distributed by state wildlife agencies, issued only to qualified individuals, enable harvest of an allotment of deer in areas targeted for population reduction, and permit the sale of whole carcasses and parts of harvested deer. Administration of a CDHL program will be taxing. State agencies alreadyareunderstaffed, but administrative and enforcement frameworks already exist for commercial harvest of publicly owned natural resources (e.g., furbearers, fish, timber) and the processing and handling of meat (e.g., USDA inspections). Revenue generated by CDHL programs could be directed back toward agencies and personnel who will administer and oversee these programs. Looking forward, we anticipate several issues mustbe addressed for regulated commercial harvestof deer to be accepted by agencies, hunters, and the public. The dogma against commercial use of wildlife may be well established. It may be difficult to mediate changesin attitudes in the wildlife community, stakeholders, and other publics. It will require adoption at all levels. State laws and regulations will need to be reviewed and some will have to be changed. Some will argue that we do not have the strength, stamina, or political will necessary to implement such broad sweeping changes. On the other hand, many wildlife managers will appreciate having an alternative tool for managing overabundant populations of white-tailed deer. We identified several benefits (reduce overabundant populations of deer; source of healthy, natural, green, locally-produced protein; economic growth, entrepreneurship, and market expansion; and public engagement and appreciation) and expected concerns associated with this concept(privatization of wildlife; overexploitation; food safety; competition with existing commodities; law enforcement; challenges of changing laws, regulations, and attitudes). We encourage a professional discussionof regulated commercial harvestto address the issue of overabundant white-tailed deer.

Isolations of Jamestown Canyon Virus (Bunyaviridae:Orthobunyavirus) from Field-Collected Mosquitoes (Diptera: Culicidae) in Connecticut, USA: A Ten-Year Analysis, 1997–2006

Jamestown Canyon virus (JCV) (Bunyaviridae: Orthobunyavirus) is a mosquito-borne zoonosis belonging to the California serogroup. It has a wide geographic distribution, occurring throughout much of temperate North America. White-tailed deer, Odocoileus virginianus are the principal amplification hosts, and boreal Aedes and Ochlerotatus mosquitoes are the primary vectors. A 10-year study was undertaken to identify potential mosquito vectors in Connecticut, quantify seasonal prevalence rates of infection, and define the geographic distribution of JCV in the state as a function of land use and white-tailed deer populations, which have increased substantially over this period. Jamestown Canyon virus was isolated from 22 mosquito species. Five of them, Ochlerotatus canadensis, Oc. cantator, Anopheles punctipennis, Coquillettidia perturbans, and Oc. abserratus were incriminated as the most likely vectors, based on yearly isolation frequencies and the spatial geographic distribution of infected mosquitoes. Jamestown Canyon virus was isolated from Oc. canadensis more consistently and from a greater range of collection sites than any other species. Frequent virus isolations were also made from Aedes cinereus, Aedes vexans, and Oc. sticticus, and new North American isolation records were established for Anopheles walkeri, Culex restuans, Culiseta morsitans, Oc. sticticus, Oc. taeniorhynchus, and Psorophora ferox. Other species from which JCV was isolated included C. melanura, Oc. aurifer, Oc. communis, Oc. excrucians, Oc. provocans, Oc. sollicitans, Oc. stimulans, Oc. triseriatus, and Oc. trivittatus. Jamestown Canyon virus was widely distributed throughout Connecticut and found to consistently circulate in a diverse array of mosquito vectors. Infected mosquitoes were collected from June through September, and peak infection rates paralleled mosquito abundance from mid-June through mid-July. Infection rates in mosquitoes were consistent from year to year, and overall virus activity was directly related to local mosquito abundance. Infected mosquitoes were equally distributed throughout the state, irrespective of land use, and infection rates were not directly associated with the abundance of white-tailed deer, possibly because of their saturation throughout the region.

Deer populations up, hunter populations down: Implications of interdependence of deer and hunter population dynamics on management

White-tailed deer (Odocoileus virginianus) are managed to yield diverse impacts, including effects to ecosystems. Many conventional hunting systems manage deer abundance through rules that strive to produce recreation opportunities and an equitable distribution of antlered bucks among hunters. To protect against excessive harvests, antlerless deer harvests often are regulated through quotas. This approach is effective when deer productivity does not outstrip capacity of the hunter population to harvest required numbers of antlerless deer. In many areas of North America, abundance of white-tailed deer has increased dramatically in the past two decades, which has caused many wildlife managers to ask whether deer populations can be controlled with conventional harvest strategies. We used population reconstruction modeling to simulate deer populations from mixed hardwood forests in southern New York, determined antlerless deer harvests needed to stabilize or reduce populations, and evaluated whether current hunting systems can effectively achieve potential ecosystem objectives. Current hunter willingness to seek or use antlerless deer permits likely is inadequate to stabilize or reduce deer densities. This situation may be exacerbated in the future with occurrence of diseases in deer or other factors that diminish hunter participation. We discuss implications for effectiveness of ecosystem management.

Winter nutritional condition of eastern coyotes in relation to prey density

In northeastern North America, coyotes (Canis latrans) contend with lower prey diversity and abundance relative to their western counterparts (Harrison 1992; Parker 1995; Patterson et al. 1998). We used urinalysis to determine if the local distribution and abundance of white-tailed deer (Odocoileus virginianus) and snowshoe hare (Lepus americanus) had a measurable effect on the nutritional condition of eastern coyotes during winter. We analyzed 567 urine specimens collected from coyotes belonging to 8 territorial family groups, whose territories contained different densities of deer and hare. Mean urinary urea nitrogen (UN) : creatinine (C) ratios were correlated positively with relative hare density (rs = 0.75, P = 0.004) but negatively with deer density (rs = -0.71, P = 0.009). Coyote-group size did not have a significant influence on mean UN:C (rs = 0.42, P = 0.17). Coyotes utilizing hare as a primary food source maintained consistently high UN:C values throughout the winter, whereas those using proportionally more deer as a primary food source exhibited lower and more variable UN:C values during the breeding season. Winter densities of deer and hare were inversely related (rs = -0.63, P = 0.027), further suggesting that the UN:C value was primarily a function of hare density. The analysis of urine voided in snow is useful for determining the relative time since last feeding for carnivores. However, inferring relative nutritional condition from time since last feeding may be inappropriate for cases in which carnivores exploit prey of different sizes.

Winter nutritional condition of eastern coyotes in relation to prey density

In northeastern North America, coyotes (Canis latrans) contend with lower prey diversity and abundance relative to their western counterparts (Harrison 1992; Parker 1995; Patterson et al. 1998). We used urinalysis to determine if the local distribution and abundance of white-tailed deer (Odocoileus virginianus) and snowshoe hare (Lepus americanus) had a measurable effect on the nutritional condition of eastern coyotes during winter. We analyzed 567 urine specimens collected from coyotes belonging to 8 territorial family groups, whose territories contained different densities of deer and hare. Mean urinary urea nitrogen (UN) : creatinine (C) ratios were correlated positively with relative hare density (rs = 0.75, P = 0.004) but negatively with deer density (rs = -0.71, P = 0.009). Coyote-group size did not have a significant influence on mean UN:C (rs = 0.42, P = 0.17). Coyotes utilizing hare as a primary food source maintained consistently high UN:C values throughout the winter, whereas those using propor...

Vegetation structure influences the burden of immature Ixodes dammini on its main host, Peromyscus leucopus.

To determine whether the relative abundance of immature Ixodes dammini (the vector of Lyme disease and human babesiosis) is related to habitat structure, we examined tick burdens on their main host, the white-footed mouse (Peromyscus leucopus), in 4 structurally diverse sites on Great Island, Massachusetts, USA. Vegetation structure at each site was quantified with respect to 25 habitat variables. Principal components analysis was used to reduce this set of habitat variables to seven new and orthogonal variables. Immature tick abundance varied widely among grids. Regression analysis of tick burdens on the habitat principal components showed that larval burdens were related strongly to the density of woody vegetation and negatively to herbaceous vegetation. Nymphal burdens were related negatively to herbaceous vegetation, but the relationship was not as strong as in the case of larvae. An experimental reduction in the abundance of white-tailed deer (Odocoileus virginianus), the main host of adult ticks, substantially reduced tick burdens and altered their relationships to habitat structure. Nymphal burdens were unrelated to habitat structure following deer removal. Manipulating habitat structure may have utility as a control strategy against this important vector.

Gastrointestinal Helminths of Raccoons (Procyon lotor) from Ossabaw Island, Georgia

An exceedingly high number of raccoons (Procyon lotor) inhabit one of the coastal islands of Georgia (Ossabaw). This area constitutes approximately 25,000 acres of high-ground in addition to an abundance of marshland, which affords an excellent habitat for many forms of wildlife. The privately owned island is 1 mile from the nearest adjacent land (St. Catherine's Island) and about 7 miles from the mainland. A swift tidal current prevails between these areas which probably prohibits the crossing of most terrestrial mammals. On Ossabaw Island there is an abundance of white-tailed deer (Odocoileus virginianus), fox squirrels (Sciurus niger), grey squirrels (Sciurus carolinensis), mink (Mustela vison) and a few otter (Lutra canadensis). This island is void of opossums (Didelphis marsupialis), bob-cats (Lynx rufus), skunks (Mephitis mephitis), beavers (Castor canadensis), black-bears (Euarctos americanus) and foxes (Urocyon cinereoargenteus or Vulpes fulva), which commonly inhabit the remote coastal plain regions. Some domestic livestock, including cattle, swine, horses and dogs is maintained and produced on the island. In view of the rather unusual circumstances and mammalian fauna of the described area, a helminth survey was made. This report is presented as a contribution to the existing knowledge on parasitism in wildlife and its ecological relationship to P. lotor.