Forest Structure and Stand Characteristics Influence the Space Use and Fine‐Scale Movements of Fishers ( <i>Pekania pennanti</i> )

ABSTRACT Understanding animal space use can inform management and conservation, particularly in landscapes where conservation of imperiled species must be balanced with resource use by humans. We used GPS collar data to evaluate fisher ( Pekania pennanti ) space use and behavior at multiple spatial scales in relation to a multi‐scale vegetation structure in the southern Cascade mountains of Oregon, USA. From 2015 to 2018, we estimated space use of 9 individual fishers collared during 25 deployments. To evaluate whether the vegetation structure affected fisher behavior within use areas, we modeled variation in motion variance and estimated fine‐scale space use using step selection functions, including evaluating where fishers exhibit selection for corridor‐type movements. Fisher use areas exhibited greater canopy cover, heterogeneity, and canopy height than stands available across the study landscape. Fishers exhibited higher motion variance as canopy cover and canopy height decreased, with the strongest effects in areas with &lt; 26% canopy cover or &lt; 23 m canopy height. Fine‐scale habitat selection by fishers was positively associated with higher canopy cover and height, and fisher corridor‐type movements were more likely to occur in symmetrically shaped, larger forest stands. Importantly, we found that fishers used greater canopy cover and height across spatial scales but exhibited asynchronous responses to structural heterogeneity at different spatial scales. At fine scales, fishers selected against heterogeneity in canopy cover and height and areas closer to stand edges and exhibited more variable movement in open or early‐seral areas. Conversely, fisher space use at coarser scales was positively related to heterogeneity in forest cover and the shape and size of forest stands. Through this work, we highlight the importance of scale‐dependent context when considering the effects of forest structure on species' space use and illustrate vegetation and patch characteristics that may promote the spaceuse offishers and other forest‐dependent species in mixed‐use landscapes.