Landscape seasonality influences the resource selection of a snow-adapted forest carnivore, the Pacific marten

Context Characterizing animal space-use and resource selection is central to effective conservation. In seasonally variable systems, animals may alter space-use to minimize risk, mediate physiological costs, and maintain access to resources. However, it is often unclear which environmental features influence space-use across seasons, and whether resource selection of non-migratory animals varies in seasonally snow-covered environments. Objectives We quantified space-use and scale-dependent resource selection of Pacific martens ( Martes caurina ) in northern California to evaluate the relative influence of abiotic (e.g., topography, weather) and biotic (e.g., forest structure) covariates on spatial ecology of martens in ecologically distinct seasons (i.e., snow-covered, snow-free). Methods We obtained fine-scale location data from GPS-collared martens (n = 26) in the Cascade and Sierra Nevada mountain ranges in California, USA. We incorporated spatially explicit weather, topographic, and forest structure data in a scale-optimized, seasonal resource selection function framework to determine the relative importance of abiotic and biotic conditions during snow-covered and snow-free periods. Results During snow-free periods, martens selected for features associated with complex forest structure, including increasing stem basal area. Conversely, space-use was associated with dense forest structure and topographic features in snow-covered periods. Though the relative influence of abiotic and biotic covariates on resource selection varied by season, the scale at which these variables best explained space-use did not. Conclusions Our results highlight seasonality and scale-dependence of resource selection by martens and emphasize the importance of understanding spatio-temporal responses of free-ranging animals to landscape heterogeneity. We suggest behavioral or ecological requirements that differ by season and scale may influence space-use and resource selection patterns, and, consequently, can inform conservation actions.