Identifying habitat characteristics to predict highway crossing areas for black bears within a human-modified landscape

Abstract

Roads and associated human development are prevalent features in many landscapes and can have significant impacts on wildlife populations, including the creation of barriers to movement that can reduce connectivity within and among populations. We evaluated how a highway in the northern Rocky Mountains influenced movements of American black bears (Ursus americanus) in a landscape modified by humans, resulting from human residences, recreation, and resource extraction. The objectives of the study were to determine habitat characteristics that were selected at locations where bears crossed the highway and develop and evaluate a predictive model for road-crossing locations based on habitat characteristics. Eleven out of 23 black bears fitted with GPS collars crossed highway 95 at least once. When bears crossed the highway they selected for specific habitat attributes, at both roadside and landscape scales, characterized by forested areas away from human development, with additional important habitat features including distance to cover, amount of shrub along the highway, and distance to water. Validation of our model with 24 independent highway crossing events from 2 years demonstrated high model predictability. We described how animal movement data can be used to identify and predict important road crossing areas for wildlife, which can assist in designing planning strategies for roadways and landscapes to facilitate wildlife movement to maintain connectivity among populations and to reduce wildlife-vehicle collisions. © 2011.