Bovine tuberculosis (bTB) caused by Mycobacterium bovis infection in Michigan white‐tailed deer (Odocoileus virginianus) has proven resistant to current management practices. The Michigan Department of Natural Resources (MDNR) is faced with managing a protracted bTB outbreak with shrinking economic resources, its initial control strategies approaching, or having reached, the limits of their effectiveness. Planning tools are needed to project the outbreak's future course and forecast the likely outcomes of proposed controls. We describe development of a spatially explicit, individual‐based stochastic simulation model of bTB in Michigan white‐tailed deer. We sought to 1) characterize whether eradication of bTB is possible by increasing hunter harvest or via vaccination, and how long it is likely to take to achieve eradication; 2) characterize the effect of concurrent deer baiting; and 3) assess the effect of baiting on the probability of bTB establishment in uninfected areas. Simulations indicated that current MDNR management strategies are unlikely to eradicate bTB from the core outbreak area's deer population within the next 30 years. A 50–100% increase (over current rates) of both antlered and antlerless deer harvest was required to achieve eradication if baiting was occurring, compared to only a 50% increase in harvest required if baiting was eliminated. Vaccination strategies required frequent application and high exposure rates (>90%) to achieve eradication, which baiting delayed. Simulations indicated that if bTB was eradicated from the core outbreak area, a single infected deer introduced into the area would be 8 times more likely to re‐establish bTB if baiting was occurring. The ability to forecast likely outcomes of disease management can be critical for wildlife managers to assess whether specific strategies are likely to be successful. Because current policy appears unlikely to achieve the stated goal of eradicating bTB from Michigan in the foreseeable future, reorienting the bTB program from eradication to controlling geographic spread and transmission to cattle may be more realistic goals. Spatial models such as ours are ideally suited to investigating spatial heterogeneity of disease transmission, and how transmission is influenced by aggregating factors such as baiting or supplemental feeding. © 2014 The Wildlife Society.

Predictive relationships between estimates of functional population connectivity and physical and biotic landscape features can provide important insights into present and future population responses to human-mediated landscape change. Quantification of associations between landscape features and dispersal or genetic surrogates such as gene flow among areas can be particularly challenging for continuously distributed and highly mobile wildlife species. We assessed the relative influence of natural and humanaltered landscape features on white-tailed deer (Odocoileus virginianus) spatial genetic structure (SGS) in southern Michigan (USA) using 7 microsatellite markers assayed for 326 adult individuals from 21 contiguous counties (33,284 km 2 ). We used previously collected telemetry data to quantify probabilities of habitat occupancy and seasonal movements that allowed selection and weighting of landscape features to create habitat suitability indices (HSI). We assigned individuals to groups (n ¼ 13) for statistical analyses quantifying relationships between measures of SGS (response variable) with Euclidean distance, least cost distances parameterized using HSI, and presence of natural (rivers) and man-made (roads) barriers to dispersal. Over the entire study area, genetic differentiation was significant (mean F st ¼ 0.019, P < 0.001) and increased with increasing inter-group geographic distance (r 2 ¼ 0.381; P < 0.05). We identified features in the landscape matrix between groups including rivers, high traffic roads, and habitats of intermediate HSI as inhibiting gene flow. Low HSI was associated with low between-group F st and appeared to facilitate gene flow. Quantification of the relative importance of man-made barriers (roads) and habitat suitability to SGS for white-tailed deer emphasizes the importance of joint use of ecological and genetic analyses in conservation and control efforts for abundant and mobile wildlife species. Ó 2014 The Wildlife Society.

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Assessment of habitat suitability provides natural resource managers with insights on the quality and spatial distribution of habitat for wildlife species. However, habitat suitability models only provide information on current habitat parameters, and do not consider changes in habitat due to forest succession and disturbances. Habitat potential models have been developed by identifying habitat types and their successional trajectories to provide insights on how landscapes change with time. We developed habitat suitability index (HSI) models and habitat potential models for elk (Cervus elaphus nelsoni) on public and private lands within the Michigan elk range (1,220 km2) in northeastern lower Michigan, USA. Our objective was to demonstrate how integration of habitat suitability and habitat potential models can provide spatiotemporal insights on wildlife habitat. When constructing public‐lands models, we used state forest compartment‐inventory data to identify cover types important to elk, and assigned suitability values (0 = low, 1 = high) to each cover type for elk life requisites (i.e., spring food, winter food, winter thermal cover). Additionally, we modified suitability values based on stand conditions acquired from state forest inventory records (e.g., stand size, percent canopy closure, age of aspen [Populus spp.]). For our private‐lands models, we used satellite imagery to classify cover types and assigned suitability values to cover types for each elk life requisite, and modified values based on percent canopy closure for winter thermal cover. Elk habitat potential was modeled by delineating habitat types by overlaying digital spatial data layers (soils, land‐type associations, vegetation) and identifying successional trajectories using habitat classification guides and literature. We assigned suitability values to each habitat type for life requisites at early to late successional stages. The highest suitability value of each habitat type's successional stage determined the habitat potential for each habitat type. Our winter thermal cover HSI model indicated several large areas (5–13 km2) of high suitability (i.e., lowland conifers) in the southern third of our study area. Our winter food HSI model indicated a heterogeneous arrangement of high suitability areas (hardwoods, upland conifers, aspen) throughout our study area. Our spring food HSI model indicated few areas of high suitability (openings) primarily on private lands. Our habitat potential models indicated high potential for each elk life requisite across the elk range. Comparisons between current elk habitat suitability and habitat potential identify key areas where managers can maximize management efforts for elk in Michigan. Areas determined to have high habitat potential (e.g., mature aspen stands) may become focus areas if they currently have low habitat suitability. Conversely, managers can avoid committing resources to areas with low habitat potential. Integrating habitat suitability and potential models provides insights on how w...

Coastal sand dunes are dynamic ecosystems with elevated levels of disturbance and are highly susceptible to plant invasions. One invasive plant that is of concern to the Great Lakes system is Gypsophila paniculata L. (perennial baby’s breath). The presence of G. paniculata negatively impacts native species and has the potential to alter ecosystem dynamics. Our research goals were to (1) estimate the genetic structure of invasive G. paniculata along the Michigan dune system and (2) identify landscape features that influence gene flow in this area. We analyzed 12 populations at 14 nuclear and two chloroplast microsatellite loci. We found strong genetic structure among populations (global FST = 0.228), and pairwise comparisons among all populations yielded significant FST values. Results from clustering analysis via STRUCTURE and discriminant analysis of principal components (DAPC) suggest two main genetic clusters that are separated by the Leelanau Peninsula, and this is supported by the distribution of chloroplast haplotypes. Land cover and topography better explained pairwise genetic distances than geographic distance alone, suggesting that these factors influence the genetic distribution of populations within the dunes system. Together, these data aid in our understanding of how invasive populations move through the dune landscape, providing valuable information for managing the spread of this species.