Characterizing Habitat Elements and Their Distribution over Several Spatial Scales: The Case of the Fisher

In past studies of the fisher (Pekania pennanti) most researchers have concluded that fisher habitat must consist of mostly mature to late-seral forest with few, if any, openings. Without doubt, certain elements found in mature to late-seral forests are required by females to successfully rear their young, but some recent work casts doubt on the extent that a continuous canopy of tree coverage and a preponderance of older stands are necessary as long as certain components exist. This paper explores this issue with an attempt to better characterize essential elements of habitat for the female fisher. This characterization is based upon fine-scale inventory plot data that is analyzed across several spatial scales that represent a small neighborhood about den sites, the forest of the 75% kernel density estimate for female home ranges, and the forested region as a whole. We present results of a test of significance in comparing habitat elements across these three scales. Our findings suggest that certain habitat elements typically found in mature to late seral forests must be present at a certain fraction of the landscape for the fisher. The approach described here may be of considerable value in developing guidelines for conservation agreements.