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

American marten are associated with forests that are characteristically late successional, closed canopy, and diverse in structure; these attributes meet their habitat requirements and provide resting sites. However, the small populations of marten in Michigan's Northern Lower Peninsula face modern habitat conditions that are fragmented and considerably altered from presettlement environments. Resting site structures are required habitat components that are used daily and provide protection from predation and inclement weather but may be limiting and require active management to preserve. We identified resting site characteristics of American marten in the Manistee National Forest from May 2011 to December 2013. Twenty-five marten (15 male and 10 female) were monitored to identify resting sites. We identified 522 unique resting site structures; tree cavities (n = 255, 48.9%), branches (n = 162, 31%), and nests (n = 90, 17.2%) were most commonly observed. During the summer (April-September) marten used more exposed tree branches (41.8%); while in the winter (October-March) they used more cavities (64.5%). Marten used structures that were associated with high percent canopy closure (>= 67%). Resting sites were found in live trees 86% of the time, and the three predominant species included oak (Quercus spp.), maple (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 nonresting site trees found at resting site locations (U ' = 268721, P = < 0.001). The average stand basal area ( (x) over bar = 33.92 +/- 9.04 m(2) ha) found in resting site plots was significantly larger than that found at control plots ( (x) over bar - 31.10 +/- 8.69 m(2) ha, P - 0.007). Maintaining complex forest structure, abundant CWD, high percent canopy closure and high basal area should be considered when managing for marten. Silvicultural techniques that promote tree species diversity, older tree age classes, and retention of CWD are all important factors to consider when managing for marten.