Browsing by Subject "Odocoileus virginianus"

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    Establishing The Feasibility Of Making Fine-Scale Measurements Of Habitat Use By White-Tailed Deer In Northern Minnesota
    (2020-01) Smith, Bradley
    Advances 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.
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    Moose and deer resource selection and co-occurrence in northeast Minnesota
    (2019-08) McGraw, Amanda
    A parasite, Parelaphostrongylus tenuis, carried by white-tailed deer (Odocoileus virginianus) has often been cited as a significant factor contributing to moose (Alces alces) population declines. Moose suffer from neurologic disease and usually die when infected with P. tenuis. The strength of the three-way relationship between moose, deer, and P. tenuis, and the resulting negative impact on moose health, is thought to be driven by deer densities. Despite its importance for moose and deer management, only one peer-reviewed study to date has tested the relationship between deer and moose densities, and therefore the potential for parasite-mediated competition between moose and deer, using empirical data. A deer density threshold above which moose populations declined was identified using the empirical data collected for the study. However, the nature of the data and apparent outliers suggest that the modeling approach used to develop that threshold may not have been appropriate. Here we tested, using data from the original study, whether alternative models, including linear models and negative binomial models would be less sensitive to outliers and could better explain the relationship between deer and moose densities in this study system. We found no evidence in our analysis that moose density decreases as deer density increases. We conclude that while the proposed moose-deer-P. tenuis relationship could be partially density dependent, additional factors such as frequency dependence of disease transmission and shared use of resources by moose and deer should also be considered.
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    R code and data for "Spatial compartmentalization: a nonlethal predator mechanism to reduce parasite transmission between prey species"
    (2021-11-15) Oliveira-Santos, L. Gustavo R.; Moore, Seth A.; Severud, William J.; Forester, James D.; Isaac, Edmund J.; Chenaux-Ibrahim, Yvette M.; Garwood, Tyler; Escobar, Luis E.; Wolf, Tiffany M.; seve0135@umn.edu; Severud, William J.
    This collection of files provides data and R code supporting the publication "Spatial compartmentalization: a nonlethal predator mechanism to reduce parasite transmission between prey species" in review at Science Advances. We provide all necessary code to reproduce the analysis along with simulated movement data of white-tailed deer, moose, and wolves.