Resource Utilization and Movements of American Marten (Martes americana) in the Eastern Upper Peninsula, Michigan

The goal of my thesis was to quantify fine scale (both spatially and temporally) American marten (Martes americana) space use, resource selection, and movement behaviors in the Eastern Upper Peninsula of Michigan. I had two main objectives, to: 1) quantify the relationships among stand-level forest inventory data, Euclidean distances, and marten space use in the East Unit of the Hiawatha National Forest (HNF), and 2) quantify marten movement behaviors and relate those behaviors to weather factors. In Chapter 1, I describe marten space use (quantified from 12 GPS-tagged marten) in the form of utilization distributions, and relate those distributions to typical forest inventory and available GIS data. I used likelihood of resource utilization probability at marten telemetry locations as the dependent variable, and stand-level age, basal area, tree diameter, tree density, and site productivity (i.e., the ability of the soil to produce and support vegetation), and distance to openings and well-traveled roads as independent variables. I found that forest inventory data, summarized at the stand level, were poor predictors of marten space utilization. I found some support for site productivity and tree density as positive correlates of resource use. For some marten, higher use areas were associated with more productive sites and in forest stands with higher tree densities. I suggest that at the stand-level, site productivity is the variable that best integrated multiple forest attributes, thereby better representing the complex forest structure knowingly used by marten. In Chapter 2, I examine daily and seasonal movements and correlated these movements to weather variables. Seasons were defined as winter (December, January, February, March), spring (April and May), summer (June, July, August), and fall (September, October, November), and weather variables included derivations of temperature, precipitation, snow water equivalent, solar radiation, and vapor pressure. I found that average daily movement rates were 13.28 m/min (SE = 0.48), and that marten were most active during winter (and least active during fall). My results indicated that marten in the HNF did not follow predictable daily activity patterns, and that movement rates were best explained by unmeasured characteristics related to individual marten and season (e.g., potentially the amount of human disturbance, conspecific interactions). I found weak support that temperature and precipitation affected daily movement rates, with movement rates decreasing as temperature increased, and movement rates increasing on days with more precipitation. My results indicated that weather is a poor predictor of marten activity and that movements are greatest in winter, likely increasing their susceptibility to harvest and predation.