White-tailed Deer Populations Research Articles

Impact of deer browsing on plant communities in cutover sites on Anticosti Island

Browsing by Anticosti Island's large white-tailed deer (Odocoileus virginianus) population reduces the abundance of the deer's preferred species and increases the abundance of less preferred species. This alteration of plant communities can lead to degradation of deer habitat. However, the centres of large clear-cuts may be spared from deer browsing given that this animal's instincts regarding predation risk impel it to remain near escape cover. This project assessed the impact of high deer populations on plant communities in large clear-cuts harvested by cutting with protection of regeneration and soils (CPRS). To this end, vegetation growing within fenced-off areas was compared with that growing in adjacent unfenced plots following application of large CPRS in 1995 and 1996. The results show that deer browsing does not have an impact on the number of plant species but does dramatically reduce total species cover. Furthermore, although the number of species was the same in the fenced and unfenced plots, some species were only found in one or the other type of plot. Rubus idaeus, Betula papyrifera, Epilobium angustifolium, Abies balsamea, Maianthemum canadense, Cornus Canadensis, and Prunus pensylvanica were all associated with fenced plots, while the cover of true grasses and Cirsium arvense increased in the unfenced plots. We conclude that large CPRS-harvested clear-cuts cannot serve to preserve the initial plant communities on Anticosti Island.

High white-tailed deer densities benefit graminoids and contribute to biotic homogenization of forest ground-layer vegetation

Biotic homogenization, with its emphasis on invasions, extinctions, and convergence in taxonomic similarity, provides an important framework for investigating changes in biodiversity across scales. Through their selective foraging, large populations of white-tailed deer are altering population sizes, driving extirpations, and facilitating invasions of plants throughout the eastern United States. I hypothesize that deer can drive biotic homogenization in forest understory communities by shifting species composition to one dominated by grasses, sedges, and ferns (all wind-pollinated plants). I report the effects of 16 years of deer exclusion in a hemlock-northern hardwood stand in N Wisconsin using a block design. Species composition showed greater convergence in control plots than exclosure plots, indicating deer can drive biotic homogenization at the stand level. Total percent cover is nearly 4 times greater in exclosure plots. Percent cover by woody plants, broadleaf herbs, and ferns is 150, 63, and 20 times greater in exclosure plots, respectively, while cover by sedges and grasses is 3.8 and 2.2 times greater in control plots. Cover by species with showy, insect-pollinated flowers is 79 times greater in exclosures. Graminoid-dominated control plots represent a novel state not observed fifty years ago, and could reflect the emergence of a grazing lawn. The increase in graminoids at this study area and throughout the region could under some global change scenarios be an early stage of conversion from forest to savanna or wood pasture.

Deer Hunting on Pennsylvania's Public and Private Lands: A Two-Tiered System of Hunters?

Recreational hunting is crucial for controlling white-tailed deer populations. Public land is increasingly important as access to private lands declines. However, differences between public and private land hunters remain unknown. Our study of Pennsylvania hunters revealed differences between private and public land hunters that may pose problems for management. Hunters who only hunted public land had lower harvest rates, especially of antlerless deer, spent less time hunting, were less committed to hunting, were more likely to hunt alone, less likely to belong to a hunting camp, and more likely to live in urban areas. They were less likely to believe that high deer populations could damage forest ecosystems, and less willing to harvest antlerless deer. The implications of these findings, in the context of already-declining hunter capacity to keep deer populations in check, and concomitant declining access to private land, are discussed

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.

EFFICACY OF ORAL AND PARENTERAL ROUTES OF MYCOBACTERIUM BOVIS BACILLE CALMETTE-GUERIN VACCINATION AGAINST EXPERIMENTAL BOVINE TUBERCULOSIS IN WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS): A FEASIBILITY STUDY

We investigated the efficacy of oral and parenteral Mycobacterium bovis bacille Calmette-Guerin Danish strain 1331 (BCG) in its ability to protect white-tailed deer (Odocoileus virginianus) against disease caused by M. bovis infection. Twenty-two white-tailed deer were divided into four groups. One group (n=5) received 10(9) colony-forming units (cfu) BCG via a lipid-formulated oral bait; one group (n=5) received 10(9) cfu BCG in culture directly to the oropharynx, one group (n=6) was vaccinated with 10(6) cfu BCG subcutaneously, and one group served as a control and received culture media directly to the oropharynx (n=6). All animals were challenged 3 mo after vaccination. Five months postchallenge the animals were examined for lesions. Results indicate that both oral forms of BCG and parenterally administered BCG offered significant protection against M. bovis challenge as compared to controls. This study suggests that oral BCG vaccination may be a feasible means of controlling bovine tuberculosis in wild white-tailed deer populations.

Feedback effects of chronic browsing on life‐history traits of a large herbivore

1. Increasing ungulate populations are affecting vegetation negatively in many areas, but few studies have assessed the long-term effects of overbrowsing on individual life-history traits of ungulates. 2. Using an insular population of white-tailed deer (Odocoileus virginianus Zimmermann; Anticosti, Québec, Canada) introduced in 1896, and whose density has remained high since the first evidence of severe browsing in the 1930s, we investigated potential feedbacks of long-term and heavy browsing on deer life-history traits. 3. We assessed whether chronic browsing contributed to a decline of the quality of deer diet in early autumn during the last 25 years, and evaluated the impacts of reduced diet quality on deer body condition and reproduction. 4. Rumen nitrogen content declined 22% between two time periods, 1977-79 and 2002-04, indicating a reduction in diet quality. 5. After accounting for the effects of year within the time period, age and date of harvest in autumn, peak body mass of both sexes declined between the two time periods. At the end of November, males were on average 12% heavier and adult does 6% heavier in 1977-79 than in 2002-04. Hind foot length did not vary between time periods. 6. The probability of conception increased 15% between the two time periods, but litter size at ovulation declined 7%, resulting in a similar total number of ovulations in 2002-04 and in 1977-79. 7. Our results suggest that following a decline in diet quality, white-tailed deer females modified their life-history strategies to maintain reproduction at the expense of growth. 8. Deer appear to tolerate drastic reductions in diet quality by modifying their life history traits, such as body mass and reproduction, before a reduction in density is observed. Such modifications may contribute to maintain high population density of large herbivores following population irruption.

Prevalence and Characterization of Bovine Viral Diarrhea Virus in the White-Tailed Deer Population in Indiana

Bovine viral diarrhea (BVD) is one of the economically important diseases of cattle. For many years, different types of vaccines have been commercially available, yet this disease is hard to control in high-density population areas. Detection and isolation of bovine viral diarrhea virus (BVDV) from any potential reservoir is vital, especially when considering virus eradication from a herd or locale. One potential source is wild ruminants. Ear notches and lymph nodes were collected from the wild population of white-tailed deer (Odocoileus virginianus) during deer hunting season in Indiana and tested for BVDV with a commercial BVD antigen capture enzyme-linked immunosorbent assay. Two samples out of 745 collected samples were positive, and subsequently cp and ncp BVDV was isolated from 1 ear notch and 1 lymph node. These isolates were genotyped as type 1a and 1b based on sequence analysis of the 5' untranslated region (UTR). The results of the present study indicate that the prevalence of BVDV in the white-tailed deer population of Indiana is about 0.3%. Wild ruminants infected with BVDV should be taken into consideration during an eradication program of BVDV from the livestock population.

On bias, precision and accuracy in wildlife aerial surveys

Bias, precision and accuracy have been studied extensively in wildlife population estimation including aerial surveys. A review of the literature shows that the concepts of bias and precision are used broadly consistently. Aerial survey data from known populations of feral pig carcases and white-tailed deer show that few density estimates are unbiased and precise. Research is needed, however, to clarify how much bias and how much precision are enough for the various types of wildlife management activities. Accuracy is used in two closely related but different ways. One set of definitions of accuracy relates to deviations from the true value (bias) and the second set relates to squared deviations from the true value (bias and precision). The implications are that authors are encouraged to clearly state which definition of accuracy they use, or focus solely on bias and precision.

Population-level effects of immunocontraception in white-tailed deer (Odocoileus virginianus)

In North America, dense populations of white-tailed deer (Odocoileus virginianus) in suburbs, cities and towns have stimulated a search for new population-management tools. Most research on deer contraception has focused on the safety and efficacy of immunocontraceptive vaccines, but few studies have examined population-level effects. We report here results from two long-term studies of population effects of the porcine zona pellucida (PZP) immunocontraceptive vaccine, at the National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, USA, and at Fire Island National Seashore (FIIS), New York, USA. Annual population change at NIST was strongly correlated with population fertility (rP = 0.82, P = 0.001); when population fertility at NIST dropped below 0.40 fawns per female, the population declined. Contraceptive treatments at NIST were associated with a 27% decline in population between 1997 and 2002, and fluctuated thereafter with the effectiveness of contraceptive treatments. In the most intensively treated segment of FIIS, deer population density declined by ~58% between 1997 and 2006. These studies demonstrate that, in principle, contraception can significantly reduce population size. Its usefulness as a management tool will depend on vaccine effectiveness, accessibility of deer for treatment, and site-specific birth, death, immigration, and emigration rates.

Registration of wildlife contraceptives in the United States of America, with OvoControl and GonaCon immunocontraceptive vaccines as examples

Overabundant wildlife populations have the potential to adversely affect wildlife habitats or pose risks to human health and safety through disease transmission and collisions with vehicles and aircraft. Traditional methods for reducing overabundant wildlife, such as hunting and trapping, are often restricted or infeasible in urban and suburban areas. Additional management options are needed. For the past 15 years, scientists with the US Department of Agriculture’s (USDA) Wildlife Services’ National Wildlife Research Center have been developing and testing contraceptive agents. This research has resulted in the development of several reproductive inhibitors and has forced regulatory bodies to determine where the regulatory authority for wildlife contraceptives will reside. The regulatory authority for contraceptives for wildlife and feral animals has recently been moved from the US Food and Drug Administration (FDA) to the US Environmental Protection Agency (EPA). The first contraceptive registered by the EPA since this move was OvoControl-G for reducing the hatchability of Canada goose eggs. OvoControl was registered in 2005 by Innolytics, LLC working in cooperation with the National Wildlife Research Center. A similar product, OvoControl-P, was registered in 2007 as a contraceptive technique for pigeons. Another product developed by the National Wildlife Research Center, GonaCon immunocontraceptive vaccine, is in the registration process for managing white-tailed deer populations. This manuscript will describe the products that have been and are currently undergoing registration as contraceptives in the United States of America, and the data required for those products.

Prion sequence polymorphisms and chronic wasting disease resistance in Illinois white-tailed deer (Odocoileus virginianus)

Nucleic acid sequences of the prion gene (PRNP) were examined and genotypes compiled for 76 white-tailed deer from northern Illinois, which previously tested positive for chronic wasting disease (CWD), and 120 negative animals selected to control for geographic location and age. Nine nucleotide polymorphisms, seven silent and two coding, were found in the sampled population. All observed polymorphisms except two of very low frequency were observed in both negative and positive animals, although five polymorphic loci had significantly different distributions of alleles between infected and non-infected individuals. Nucleotide base changes 60C/T, 285A/C, 286G/A, and 555C/T were observed with higher than expected frequencies in CWD negative animals suggesting disease resistance, while 153C/T was observed more than expected in positive animals, suggesting susceptibility. The two coding polymorphisms, 285A/C (Q95H) and 286G/A (G96S), have been described in white-tailed deer populations sampled in Colorado and Wisconsin. Frequency distributions of coding polymorphisms in Wisconsin and Illinois deer populations were different, an unexpected result considering the sampled areas are less than 150 km apart. The total number of polymorphisms per animal, silent or coding, was negatively correlated to disease status. The potential importance of silent polymorphisms (60C/T, 153C/T, 555C/T), either individually or cumulatively, in CWD disease status has not been previously reported.

Effectiveness of Spayvac® for Reducing White-tailed Deer Fertility

Overabundant white-tailed deer (Odocoileus virginianus) populations have been reported in many urban and suburban communities across the United States. Large populations of deer can potentially increase the risk of human-wildlife conflicts, such as deer-vehicle collisions, transmission of disease to humans, and vegetation damage. In 2003, efforts to control white-tailed deer numbers were initiated at the National Aeronautical and Space Agency's (NASA) Lyndon B. Johnson Space Center (JSC) in Houston, Texas, using the long-lasting, single-dose contraceptive SpayVac. Our objectives were to evaluate the effectiveness of SpayVac for reducing white-tailed deer fertility and determine the partial cost for treatment. Between 2003 and 2004, we monitored 45 adult female deer (34 treated with SpayVac, 11 controls treated with a placebo). Fawning rate over 2 yr for deer treated with SpayVac >30 days prior to the rut was 0% (n=31), whereas the fawning rate for control deer was 78% (n=11). Inoculation 1 mo prior to the breeding season was sufficient time to achieve fertility control. We conclude that SpayVac can effectively reduce the fertility of urban white-tailed deer.

Seasonal Variation in Sex Ratios Provides Developmental Advantages in White-tailed Deer, <em>Odocoileus virginianus</em>

Since Trivers and Willard first proposed their hypothesis concerning the adaptive advantages of producing a particular offspring sex in relation to maternal condition in 1973, it has been at the forefront of scientific research concerning sex ratios with most subsequent studies focusing on maternal condition as a key contributor to variations in sex ratios. Another factor that could greatly influence sex ratios, although has been only infrequently examined in mammalian species, is birth date. We investigated how birth date influenced offspring sex ratios in White-tailed Deer (Odocoileus virginianus). Since date of birth can greatly influence an individual’s fitness and reproductive success, we suggest that birth date may be an alternative strategy in determining offspring sex ratios. Since it has been shown that the lifetime reproductive fitness of a mother can be increased by producing a particular sex during a particular time, we hypothesized that more male offspring should be born earlier in the season due to their increased reproductive potential from being born at this time. Offspring born earlier will have a head start in development and therefore have greater potential for increased body size and dominance later in life, traits that greatly influence male reproductive success. In this study, we found that maternal condition did not affect offspring sex ratio in a captive population of White-tailed Deer in Michigan; however, birth date did. We found that more males tended to be born during the second and fourth birthing periods, while more females were born during the first, third and fifth periods. In addition, we found that males born earlier in the season had greater mass the following spring than those born later, a trend that was not as dramatic in females. These results lend moderate support to our hypothesis that in White-tailed Deer offspring sex will tend to vary according to timing of birth and relative reproductive advantages gained by a particular sex being born at that time.

Browsing of tree regeneration by white-tailed deer in large clearcuts on Anticosti Island, Quebec

Browsing by the substantial population of white-tailed deer ( Odocoileus virginianus Zimmermann) on Anticosti Island hampers the regeneration of balsam fir ( Abies balsamea (L.) Mill.), which is both the deer's preferred food and shelter. The island's original fir stands have gradually been replaced by stands of white spruce ( Picea glauca (Moench) Voss), as this species is rarely browsed by the deer. This project assesses the impact on the regeneration of balsam fir and companion species by large clearcuts performed using cutting with protection of regeneration and soils (CPRS). To this end, fenced-off areas adjacent to unfenced areas were established in 1995 and 1996 in large CPRS clearcuts. The results show that the distance from forest edge does not influence the stocking, number and height of seedlings, while browsing does reduce these variables in the case of fir and paper birch ( Betula papyrifera Marsh.). However, stocking, number and height of white spruce seedlings were unaffected by both deer browsing and distance from forest edge. Woody debris seemed to protect balsam fir seedlings from browsing 8 years after cutting, but this protection should likely stop when seedlings will outgrow woody debris. It thus appears that large CPRS clearcuts will not permit the regeneration of balsam fir on a level sufficient for re-establishing fir stands on Anticosti Island.

Spatial analysis of Mycobacterium bovis infection in white-tailed deer ( Odocoileus virginianus) in Michigan, USA

The wild white-tailed deer ( Odocoileus virginianus) population in Michigan, USA, has endemic Mycobacterium bovis. We determined whether there were spatial clusters of retrospective TB cases in white-tailed deer in northeastern Michigan and identified specific factors associated with the spatial clusters. Data from hunter-harvested deer (age, gender, TB status, and geographic section) were collected by the Michigan Department of Natural Resources (MDNR) during TB surveillance from 1995 to 2002. Land cover (vegetation, land-use) and land type (soil types and drainage characteristics, landforms) described potential deer habitats. Specific locations of large-scale supplemental feeding sites were collected from the MDNR aerial surveillance program from 1997 to 2002. Analyses were conducted using principal components derived from environmental data (and other risk factors) on spatial clusters of disease (identified by the spatial scan statistic). Spatial effects were incorporated into the multivariable analyses by using a neighborhood approach. A total of 420 deer with M. bovis infection were identified from 1995 to 2002, out of 39,451 harvested deer from 3216 TRS units, and spatial clusters of cases were identified. A total of seven principal components of environmental data were generated. Clusters were associated with the presence of large expanses of deciduous forests on moraine ridges separated by low areas of forested wetlands, and the presence of many small lakes. Factors that promoted congregation of deer for extended periods of time (natural cover, access to water, and less human contact) appeared to be associated with increased odds of TB positivity. This suggests that there are specific areas where interventions can be implemented to reduce congregation of animals and disrupt the cycle of infection transmission.

A Paleozoological Perspective on White-Tailed Deer (Odocoileus virginianus texana) Population Density and Body Size in Central Texas

Archaeological and paleontological datasets are used in conservation to add time-depth to ecology. In central Texas, several top carnivores including prehistoric Native American hunters have been extirpated or have had their historic ranges restricted, which has resulted in pest-level white-tailed deer (Odocoileus virginianus texana) populations in some areas. Differences in body size of deer between prehistory and modernity are expected, given that a lack of predation likely has increased intraspecific competition for forage among deer, resulting in smaller body size today. In fact, modern deer from settings without harvest pressure are significantly smaller than those from harvested areas and from prehistoric deer. From a natural history perspective, this research highlights potential evolutionary causes and effects of top-predator removal on deer populations and related components of biological communities in central Texas.

Survey on ‘lumpy jaw’ on deer farms in western Canada: Prevalence and distribution, and identification of associated factors

AIM: To investigate the prevalence and geographical distribution of ‘lumpy jaw’ (LJ) in a population of white-tailed deer (WTD; Odocoileus virginianus) and mule deer (MD; Odocoileus hemionus) farms from the western Canadian provinces of Saskatchewan and Alberta, and to identify factors associated with its occurrence. METHODS: A cross-sectional study, in which the target population was all farmers of WTD and MD registered in Saskatchewan and Alberta, was conducted between July 2004 and January 2005. A questionnaire was mailed to all farmers requesting information about the presence of LJ and other necrobacillois-related syndromes (footrot and fawn death syndrome), and various farm characteristics, during 2002, 2003 and 2004. Herd and within-herd incidences of disease were estimated. Global and local spatial analyses were performed to identify possible clusters of occurrence of LJ in the region. Logistic regression analysis was used to identify factors associated with the occurrence of LJ. RESULTS: A total of 139/268 (52%) deer farmers responded to the survey. Over the entire study period, 108/139 (78%) of farmers reported having cases of LJ in their herds, and in any given year the incidence amongst herds was about 40%. The presence of footrot was not associated with the presence of LJ. The proportion of fawns dying suddenly in 2004 was higher on farms affected by LJ than in those considered LJ-free (median of 11.1% and 0%, respectively; p<0.001). Two areas in Saskatchewan were identified as having a higher herd prevalence of LJ (clusters) than all other areas. Density of animals, moving and handling animals, lack of basic hygiene measures, and bottle-feeding of fawns increased the odds of a herd being affected by LJ. CONCLUSIONS AND CLINICAL RELEVANCE: LJ should be considered a common disease in farmed deer in western Canada. The observed relationship between the occurrence of LJ and acute mortality of fawns emphasises the potential of this infection to result in significant economic loss. Intensive management of deer, characterised by high densities and frequent moving and handling of animals, may contribute significantly to the occurrence of LJ. Observed geographical clusters may reflect areas where management of deer was more intensive or the trading of deer more common.

The Role of Ethical Judgments Related to Wildlife Fertility Control

Certain species of wildlife cause considerable damage and therefore receive management attention. Traditional management methods rely on lethal control, but fertility control is increasingly being advocated as a more humane alternative. Because wildlife management decisions are influenced by citizen input, it is important to understand what makes people support or oppose lethal control and fertility control. We studied six U.S. communities trying to manage large populations of white-tailed deer or feral cats and categorized the ethical arguments citizens used to support their positions on lethal and fertility control methods. We identified two broad categories of ethical arguments. Arguments in the “obligations to people” category focused on (1) decision-making procedures, (2) public policy decisions, and (3) management outcomes. Arguments in the “obligations to animals and the environment” category focused on (1) life, suffering, and death, (2) altered characteristics of animals, (3) individuals and communities, and (4) invasive species impacts.

Effectiveness of the State Soil Geographic Database (STATSGO) to Predict White-Tailed Deer Morphometrics in Mississippi

The State Soil Geographic Data Base (STATSGO) developed by the Natural Resources Conservation Service is a spatially explicit database of soil characteristics known to influence the distribution, abundance, or quality of vegetation, which ultimately may affect white-tailed deer (Odocoileus virginianus) population phenotype. The national availability of STATSGO makes it an attractive tool for wildlife ecologists to use for explaining variation in deer population morphometrics. We constructed linear regression models relating site-specific mean population 1.5-year female body mass and 2.5-year male antler size to soil pH, organic matter, bulk density, and available water capacity values from STATSGO to evaluate the explanatory power of the database. For comparison, we developed general linear models that related the same deer morphometrics to nominal classification variables that represented 4 soil regions in Mississippi, USA. At the statewide level, regressions using site-specific soil pH, organic matter, bulk density, and available water capacity values from STATSGO did not explain more variation than did regional classification models. Although STATSGO did not generate good models for predicting or explaining localized variation in white-tailed deer morphometrics in Mississippi, it did reveal differences in soil properties that may influence white-tailed deer populations at regional spatial scales. At the statewide level, soil resource region classification models may be a more effective tool because they explained similar variation in deer morphometrics, and model input is easier to obtain.

Effect of Population Demographics and Social Pressures on White-Tailed Deer Dispersal Ecology

Abstract Dispersal of yearling male white-tailed deer (Odocoileus virginianus) can have profound effects on population demographics and can adversely affect population estimates and management objectives. The relationship among population demographics, social pressures, and dispersal ecology is not clear and warrants scientific evaluation. The age structure and sex ratio of the white-tailed deer population at Chesapeake Farms, Maryland, USA, changed after implementation of quality deer management (QDM). Following Rosenberry's (1997) pre-QDM study on white-tailed deer dispersal, we conducted a post-QDM study on white-tailed deer dispersal at Chesapeake Farms. The objectives of our study were 1) to compare pre- and post-QDM emigration, immigration, survival, and behaviors of yearling males, 2) to evaluate inbreeding avoidance and sexual competition hypotheses as mechanisms of dispersal through behavioral comparisons of dispersers and nondispersers, and 3) to evaluate the maternal aggression hypothesis by co...