Bobcats in southern California respond to urbanization at multiple scales

Urban areas impact wildlife populations through multiple pathways, notably habitat fragmentation and degradation. Wildlife can respond to development and other human-driven environmental change at multiple scales, from the individual to the population level, ultimately driving biodiversity patterns and processes in built and adjacent natural landscapes. However, multiple scales of space use are rarely considered in an integrated framework. Focusing on bobcats, a species associated with intermediate sensitivity to development, we explored factors affecting multi-scale space use and population density across San Diego County, a region in southern California characterized by a pronounced development gradient. We used remote camera data and GPS collar data in an integrated spatial capture-recapture + resource selection function approach. At the individual scale, bobcats selected against developed areas, while at the population level, bobcat densities were higher in habitat patches surrounded by development, suggesting that bobcat populations in these areas may be experiencing home range pile-up, a manifestation of the fence effect. Our results provide an integrated multi-scale view of the impacts of human-modified landscapes on wildlife, confirming that research on space use at the individual and population levels should be considered jointly to advance understanding of the mechanisms driving wildlife response to development. This approach has promise to improve conservation and management efforts for urban wildlife.