Structure of fisher (Pekania pennanti) habitat in a managed forest in an interior Northern California coast range

Abstract

Forest management planning across the Sierra Nevada and Northern California includes several focal wildlife species, one of which is the fisher, recently reclassified as Pekania pennanti (Sato et al. 2012) from Martes pennanti. This article presents an analysis of fisher habitat associated with privately owned forestland in Northern California. We take advantage of a high-resolution inventory database to show selective use of female fishers within this landscape. This landscape can be thought of as a matrix containing scattered mature stands of conifers and hardwoods (age >100 years) within a landscape of younger mixed conifer stands and numerous openings (24% of the area). Although stand and forest averages for habitat elements appear to score poorly using a widely used metric, we demonstrate through a new form of spatial sampling using a Kolmogorov-Smirnov (K-S) statistical test, which we call k-max, selective habitat use by female fishers at a relatively fine scale. This approach is novel in terms of generating population-level inferential results that are sensitive to smaller scale selection behavior, demonstrating that existing large structures, even though limited in areal extent, are critical elements in female fisher habitat.