MULTISCALE EFFECTS OF FOREST ROADS ON BLACK BEARS (URSUS AMERICANUS)

As the vast network of roads continues to expand across the continent, so too does the necessity to understand the associated ecological effects. To appropriately assess the impacts of these roads on wildlife it is necessary to evaluate how they affect ecological processes at multiple spatial and temporal scales. In particular, where hunting is associated with road access, roads may induce heightened behavioral responses. I assessed the effects of forest roads on habitat selection and activity patterns of a population of black bears (Ursus americanus) in the Coeur d’Alene Mountains of northern Idaho, USA. This black bear population is exposed to high hunting and recreational pressure facilitated by a dense network of forest roads and its close proximity to Coeur d’Alene, Idaho and Spokane, Washington. Current hunting season structure allows for use of bait and dogs in spring and portions of the fall seasons, with an additional non-lethal summer pursuit season. I used Global Positioning Systems (GPS) locations collected at 20 minute intervals from 25 collared adult bears from June 1 2007 through November 2008 to elucidate the multi-scale effects of roads on black bear habitat selection, activity patterns and movement rates. I hypothesized that the effects of roads on black bears would be scale dependent, such that at larger spatial and temporal scales roads would have little effect on habitat use, whereas at finer spatiotemporal scales habitat selection, behavior and movement rates of black bears would be affected by roads as traffic volumes increased. While habitat selection varied by month as well as by gender, selection for features presumably associated with risk (canopy cover and distance to roads) and activity patterns near roads illuminated an apparent trade-off between the costs and benefits associated with spending time near roads. This work suggest that although areas adjacent to roads likely contain resources desirable to bears, the risks associated with these areas require them adjust their use of and activity patterns within these areas so as to minimize mortality risk. Manipulation of road access and season dates may be a useful management tool to affect the vulnerability of bears to hunter harvest