Den Site Characteristics and Kit Survival of American Marten in West Michigan

American marten (Martes americana) were extirpated from Michigan\u27s Lower Peninsula by the early 1900s due to logging and fur trapping. In 1986, 36 marten were reintroduced to the Manistee National Forest (MNF), but the population has not grown as expected. We documented kit survival and identified den sites used by six female marten in the MNF from April through August 2012. Dens were located with radio telemetry and kits were monitored using remotely triggered cameras. Den site attributes were compared to random sites at the local and landscape levels. We confirmed 28 unique den structures, including cavities in live trees (25), snags (2) and one down log. The mean DBH of den trees was approximately 55cm. Marten utilized dens within red pine stands significantly more than expected based on abundance. Kit survival does not appear to be limiting the population. However, we recommend maintaining large diameter hardwood trees with cavities and red pine stands as a management priority