How do roads affect black bears?
Roads may have a significant effect on bears by fragmenting, altering, or removing habitat, changing movement patterns, or producing mortality through road kill or increased vulnerability to hunting and poaching. Black bears may readily cross limited access roads and trails in response to the availability of seasonally abundant foods. Bears may also use lightly traveled roads as travel pathways. The degree of avoidance of roads depends on traffic volume, noise level, amount of roadside concealment cover, sex of the bear, season of year, and time of day. Black bears readily cross roads with traffic volumes <100 vehicles/day, but avoid roads with volumes >10,000 vehicles/day. Based on studies in 3 states, bears avoided a roadside buffer zone averaging 1640 feet. Including this buffer zone, the habitat loss from 4-lane state and interstate highways varies from 212 to 222 acres per mile. Road mortality typically kills more male bears than females and is highest in spring and early summer w
