While the ability to move between habitats is critical for the viability of animal populations, the spread of urbanization is continuously adding barriers within the natural landscape; the most pervasive of which is the construction of roads and highways. The ideal situation of using existing structures, such as train and road underpasses and water culverts for wildlife cannot be assumed for all animal species, as it may also be that human use of structures is a deterrent for specific wildlife. Employing 36 wildlife cameras at 9 underpasses below Highway 10 East, our research provides 9 months of continuous, standardized, and non-invasive observation of human and mammal use, in order to (1) estimate the permeability of the road for medium and large mammals and (2) to determine the effect of human use of underpasses on the use by medium and large mammals. Over a maximum period of 315 continuous observation days at each of 9 underpasses, a total of 1450 individuals from 10 medium to large mammalian species were observed: white-tailed deer, coyote, bobcat, black bear, red fox, fisher, raccoon, mink, otter, and marmot. All three types of underpasses monitored, train, road, and culvert, were used by mammals to cross below Highway 10. The effect of human use varied depending on structure type and by species of mammal. Recommendations to increase the use of all underpasses by wildlife include addition of a dry pathway through all culverts, highway fencing along mortality hotspots, and whenever possible, dedicated wildlife under/overpasses to increase the permeability of the highway to large mammals.
(Co-presented with Caroline Daguet, Corridor Appalachian)