We are using bobcats (Lynx rufus) as a model organism to examine how roads affect the abundance, distribution, and genetic structure of a wide-ranging carnivore. First, we compared the distribution of bobcat-vehicle collisions to road density and then estimated collision probabilities for specific landscapes using a moving window with road-specific traffic volume. Next, we obtained incidental observations of bobcats from the public, camera-trap detections, and locations of bobcats equipped with GPS collars to examine habitat selection. These data were used to generate a cost-surface map to investigate potential barrier effects of roads. Finally, we have begun an examination of genetic structure of bobcat populations in relation to major road networks. Distribution of vehicle-killed bobcats was correlated with road density, especially state and interstate highways. Collision models suggested that some regions may function as demographic sinks. Simulated movements in the context of the cost-surface map indicated that some major roads may be barriers. These patterns were supported by the genetic structure of bobcats. The sharpest divisions among genetically distinct demes occurred along natural barriers (mountains and large lakes) and in road-dense regions. In conclusion, our study has demonstrated the utility of using bobcats as a model organism to understand the variety of threats that roads pose to a wide-ranging species. Bobcats may also be useful as one of a group of focal species while developing approaches to maintain existing connectivity or mitigate the negative effects of roads.

No abstract

Efforts to retain ecological connectivity have become a conservation priority to permit animal movements within home ranges, allow dispersal between populations and provide opportunities for animals to respond to climate change. We used expert-opinion and empirically derived models to investigate landscape connectivity at two spatial scales among bobcats Lynx rufus in New Hampshire, USA. Paths of marked bobcats were compared to random movements in the context of program CIRCUITSCAPE. At the local scale (within home ranges), the empirical model (based on observations and telemetry locations) performed better than the expert-opinion model. At the regional scale (state of New Hampshire), both models identified urban development as a potential barrier; however, the models differed in predicting how specific natural features (e.g. mountains and large water bodies) and some roads affected bobcat movements. When compared with bobcat population structure based on genetic information, the expert-opinion model overestimated the influence of roads. Alternatively, the empirical model overestimated the influence of snow.Our findings indicate that the empirically based resistance model was better at describing landscape-scale effects, whereas the expert-opinion model provided a good understanding of gene flow at a regional scale. As such, both models may be considered complementary. Bobcats were sensitive to disruptions imposed by habitat fragmentation and thus may be a suitable focal species for evaluating the consequences of land-use changes on the regional suite of mesocarnivores.