Resting Site Characteristics of American Marten in the Northern Lower Peninsula of Michigan

American marten are usually associated with forests that are characteristically late successional, closed canopy, and diverse in structure; attributes that meet habitat requirements and provide resting site structures. Resting site structures are required habitat components that are used daily and provide protection from predation and inclement weather. I identified resting site characteristics of American marten in the Manistee National Forest in Michigan’s Lower Peninsula from May 2011 to December 2013. Twenty five marten (15 male and 10 female) were monitored using radio telemetry to identify what types of resting sites structures were used. I identified 522 unique resting site structures; tree cavities (n = 255, 48.9%), branches (n = 162, 31%), and nests (n = 90, 17.2%) were the three most commonly observed structures being used. During the summer season (April-September) marten used more exposed tree branches (41.8%), while in the winter (October-March) they used more cavities (64.5%). Marten were observed using structures in live trees 86% of the time. Live trees used by marten included oak species (Quercus spp.), maple species (Acer spp.), and red pine (Pinus resinosa). Trees used as resting sites had significantly larger mean diameter at breast height (DBH) than the average DBH of non-resting site trees found at resting site locations. The average stand basal area (33.9 m2/ha) found in resting site plots was significantly larger than that found at control plots 60 meters away. Maintaining complex forest structure, abundant CWD, high percent canopy closure and high basal area should be considered when forest management guidelines are being drafted. Silviculture techniques that promote tree species diversity, older stand age classes, and retention of CWD are all important factors to consider when managing for marten. I recommend using a single-tree selection method for timber harvest in core marten habitat, which should allow loggers to retain larger diameter trees, pockets of higher basal areas around resting site structures, and abundant CWD. Additionally, the single-tree selection approach should promote an uneven-aged forest that will maintain a complex vertical and horizontal forest structure