Browsing by Subject "White-tailed deer"
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Item Deer Impacts on forested communities and Canada Yew Populations at Apostle Islands National Lakeshore, Wisconsin(2013-08) Maragi, Frank AnthonyAbundant white-tailed deer (Odocoileus virginianus) present a significant management problem in forested landscapes of North America. Conserving vulnerable communities requires quantifying herbivory levels and the density of the herbivore populations. The current study was conducted in 2006 to investigate the status of white-tailed deer throughout Apostle Islands National Lakeshore and their impacts on forest communities as well as Canada yew (Taxus canadensis) populations. Deer densities were estimated using fecal pellet surveys across islands of known deer occupancy. Using a defecation rate of 34.4 pellet groups deer-1 day-1, population estimates on Sand (8.23 deer km2) and York (7.68 deer km2) islands were considerably greater than Basswood (1.82 deer km2) and Oak (1.56 deer km2) islands. The variation in deer density reflects measurable differences in forage availability and browse quality between islands. Browse intensity and electivity indices revealed that northern white cedar or hemlock were selected for browsing by deer on Basswood and Oak islands, yet when Canada yew was abundant (on other islands) they were selected against. Dimensional analyses of browsed and unbrowsed stems were used to assess annual browse biomass production and utilization of Canada yew by white-tailed deer. A species-specific allometric relationship of stem diameter and shoot biomass was developed for Canada yew and used to predict the total browse biomass consumed at the stem level. Estimates of annual browse production and utilization from York and Sand islands revealed that deer herbivory accounted for 53% and 74%, respectively, of new browse biomass losses. Deer populations and herbivory levels on Sand and York islands are not sustainable for continued growth and reproduction of Canada yew populations, which are regionally uncommon. Landscape composition and species susceptibility to herbivory should be important considerations in the management of deer populations across Apostle Islands National Lakeshore.Item Establishing The Feasibility Of Making Fine-Scale Measurements Of Habitat Use By White-Tailed Deer In Northern Minnesota(2020-01) Smith, BradleyAdvances in technology enhance our ability to understand wildlife-habitat relationships. The Minnesota Department of Natural Resources’ new statewide white-tailed deer (Odocoileus virginianus) management plan aims to enhance its ability to maintain regional deer numbers near population goals. Habitat management is acknowledged as a key component to achieving the plan’s objectives. Informed habitat management prescriptions, based on an improved understanding of optimal size, shape, and arrangement of forest stands and foraging sites, and edge relationships, will contribute to a more successful integration of long-term forest and deer habitat management strategies. The objectives of my study were to establish the feasibility of combining cutting-edge Global positioning system (GPS) collar, remote sensing, and Geographic Information System technologies to 1) classify and inventory available habitat on deer winter ranges and 2) characterize how deer use habitat at the stand level to facilitate an improved understanding of their habitat requirements in northern Minnesota. During winter 2017–2018, 20 adult female deer were captured and fitted with GPS collars on 2 study areas (10/site) in northcentral (Inguadona Lake [IN]) and northeastern (Elephant Lake [EL]) Minnesota, with an additional 40 collars (20/site) deployed during winter 2018–2019. Prior to the deployment of GPS collars on free-ranging deer, I conducted stationary tests to evaluate the location-fix-success and spatial accuracy of 48 collars placed in 4 different cover types. The overall mean location error of the GPS collars was 5.7 m (± 0.15, range = 0–189), with errors in dense conifer (10.3 ± 0.52, range = 0–189 m) being greater than in hardwood stands (6.2 ± 0.22, range = 0–91 m), browse patches (3.2 ± 0.08, range = 0–26 m), and openings (3.2 ± 0.08, range = 0–32 m). With incorporation into the collars of quick fix pseudoranging (QFP) programming, I recovered 100% of the location-fixes during the stationary tests and from 30 collars deployed on free-ranging deer. Spatially, dense conifer stands accounted for 21% and 9%, and moderately dense conifer stands for 4% and 10% of the EL and IN sites, respectively. The proportion of forage openings was 9% on both sites. The mean size (area) of available dense conifer stands was similar on both study sites (6.7, 95% CI = 4.94–8.54 ha vs 6.0, 95% CI = 4.68–7.23 ha). Available forest stands were generally circular, providing a larger core area and less edge, with a mean edge:area ratio <400 m/ha. Deer use of cover types was highly variable among individuals. Mean individual use of dense conifer stands was 23% (range = 0–79%) and 9% (range = 0–29%), and mean use of forage openings was 13% (range = 0–42%) and 24% (range = 0–70%) at the EL and IN sites, respectively. To better understand deer use at the stand level and the arrangement of cover types, I measured the distance from each location-fix to the nearest dense conifer stand and forage opening. While using forage openings, deer were a mean of 177 m (± 7, range = 0–833) and 195 m (± 4, range = 0–882) from dense conifer stands at EL and IN. Likewise, individuals using dense conifer stands were a mean of 241 m (± 6, range =0–777) and 147 m (± 8, range =0–1,030) from forage openings at the respective sites. The use of an integrated technological approach is essential to a more thorough understanding of seasonal habitat requirements of deer. The ability to retrieve 100% of location-fixes with high spatial accuracy will allow us to confidently assess winter habitat use by white-tailed deer as winter progresses and assist managers in formulating prescriptions that effectively integrate forest and habitat management strategies and activities.Item The Identification of Differentially Expressed Genes in Nasal Swabs from Chronic Wasting Disease-Infected White-tailed Deer(2023) Zou, PeizhiChronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) or prion disease, which is spreading in cervid populations, including mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginianus), and Rocky Mountain elk (Cervus elaphus nelsoni). The pathogen of CWD is the abnormally misfolded prion protein (PrPsc) which is converted from normal function cellular prion protein (PrPc). PrPc is coded by the PRNP gene, which is highly expressed in the central nervous system (CNS) and also expressed in the peripheral nervous system. The specific biological function of PrPc in CNS still remains unclear, and the pathogenesis of the PrPsc also needs a better understanding. CWD is spreading fast in many places around the world, and CWD is fatal to all infected animals with no treatment or vaccine for it. Our final goal of this research is to develop a diagnosis and treatment approach for CWD. I hypothesize that there are differentially expressed genes (DEGs) caused by CWD in the nasal brush samples, and the identified DEGs could be used for CWD diagnosis. This study used next-generation total RNA sequencing to identify potential biomarkers in nasal swab samples from CWD white-tailed deer and increase understanding of CWD pathogenesis. We annotated and filtered genes from the reference genome and identified DEGs consistently altered in late-stage post-infection samples. Additionally, we performed Gene Set Enrichment Analysis for these identified genes at each time point, and we found cell proliferation pathways were suppressed, and immune response pathways were activated post-CWD infection. These biomarkers and pathways could provide some new insights into CWD diagnosis and CWD treatment for future research.Item Initial effects of structural complexity restoration treatments and deer browsing on ground-layer community composition and tree regeneration in northern hardwood forests(2014-03) Reuling, Laura F.As researchers realize the value of old-growth forests and their unique attributes and dynamics, managers have begun developing management regimes aimed at restoring old-growth characteristics in forests managed for wood products. However, changes in these forests since European settlement, especially increased population of white-tailed deer (Odocoileus virginianus Zimmerman) may have important implications for forest composition and regeneration. The objective of this research was to determine the initial (three- and four-year) effects of several old-growth structural restoration treatments and browsing by white-tailed deer on tree regeneration and understory community composition in northern hardwood forests in northern Wisconsin, USA. Community composition and tree regeneration were measured in stands with six different silvicultural treatments replicated across three large study areas (> 50 ha). Treatments consisted of a combination of two levels of coarse woody debris and three overstory gap treatments designed to emulate patterns of natural gap and mesoscale canopy disturbance: small gaps (10.7m diameter), large gaps (18.3 and 24.4m diameter), and a mesoscale wind disturbance treatment consisting of 0.4 and 1.2 ha shelterwoods. All treatments included multiple small deer exclosures to examine the impact of deer herbivory. Assessment of cover by herbaceous plants and seedlings indicated that overstory treatments had a larger effect on understory community composition than browsing by deer, whereas there was no effect of coarse wood levels. Species richness was highest in the small gap treatment and lowest in the control stands, possibly reflecting the increased dominance by a few ruderal and exotic species in treatments with increased canopy openness. Richness was also significantly lower inside exclosures than outside in some treatments, although browse-sensitive Trillium spp. were largely restricted to exclosures. Post-harvest seedling density increased with increasing overstory removal, with the mesoscale wind disturbance treatment containing the highest seedling density after three years. While browse protection generally did not have a significant effect on overall density of regeneration, several species, especially Betula alleghaniensis benefited from protection from deer browse. These initial results underscore the utility of natural disturbance-based treatments at increasing the complexity of second-growth communities and the importance of accounting for herbivory impacts on treatment responses.Item Integrating social considerations into managing white-tailed deer in Minnesota.(2009-11) Cornicelli, Louis JamesIn Minnesota, 500,000 deer hunters annually harvest in excess of 200,000 deer and recent population size can be described as historically high. Integrating social carrying capacity with biological population objectives is a new concept for agency professionals who have historically managed white-tailed deer populations primarily for hunting interests. To manage overall population size, the Minnesota Department of Natural Resources (DNR) sets harvest objectives to determine the number of deer that should be taken in a given area. However, those objectives were set with no clearly defined deer population objective or long-term strategy for managing over-abundant populations, nor was there a mechanism to address situations where harvest opportunity was exhausted. To that end, I developed a method to identify statewide deer population objectives using a public participatory process. Concurrently, I evaluated the attitudes of deer hunters towards regulatory change and implemented a choice methodology to force selection of a management strategy that might achieve a population objective. Over a 3-year period, I also evaluated the attitudes and motivations of hunters participating in experimental regulations to determine factors that contribute to future hunt participation.Item Understanding animal movements to inform bovine tuberculosis surveillance: a framework for a targeted approach(2013-08) do Rosario Ribeiro Lima, Joao PauloBovine tuberculosis (bTB) is a zoonotic disease that affects domestic and wildlife species. In recent years in the US, a novel scenario for bTB has arisen, characterized by sporadic outbreaks in cattle populations across the country and by spillover of the infection to wildlife. The cattle production system in the US continues to change, with the number of cattle farms declining but the number of cattle per farm increasing. Furthermore, cattle are moved long distances for trade and production purposes. Also the drought has encouraged a large number of cattle to move from severely affected southern states to northern states, such as Minnesota with available feed and water resources. This reality poses a threat to the biosecurity of the Minnesota cattle population and agricultural industry, due to the risk of introduction of bTB from which the state is now free. The objective of the studies presented here was to develop a new framework for bTB surveillance based on risk profiling of herds and regions. The fundamental concept from which the current work originates is that infectious disease transmission is not a random process but is modulated by risk factors that enhance its occurrence. The primarily concern in disease-free areas such as the state of Minnesota should be the identification of those key players, in this case farms and/or regions, that are at higher risk of disease introduction, and secondly to identify those farms and/or regions that would cause greater impact in the cattle population and wildlife populations if infected. The ultimate goal is to develop a targeted approach to bTB surveillance in order to increase system accuracy and cost-effectiveness which, although effective in the past, has failed recently to prevent continuing outbreaks in US cattle and wildlife populations. The combination of the studies presented in this doctoral dissertation provides a systems approach to bTB surveillance, especially at the wildlife and cattle interface. It develops a framework for a targeted surveillance system by developing approaches to identify at risk cattle premises and regions where disease is both more likely to be introduced and spread.