Some authors have hypothesized that observed increases in small mammal populations with increasing road density (after controlling for habitat effects) are due to predation release. Predation could be reduced in areas with high road density because of negative effects of roads on predator numbers and/or hunting activity. However, there are no studies testing the relationship between road density and predation rate on small mammals. Based on the predation release hypothesis, we predicted that white‐footed mouse (Peromyscus leucopus) individuals placed in sites with higher surrounding paved road density and/or closer to a paved road would experience fewer predation attempts than P. leucopus individuals placed in sites with lower surrounding paved road density and/or farther from a paved road. We recorded predation attempts on P. leucopus placed in wire mesh enclosures, using motion‐triggered cameras, at 28 sites ranging widely in surrounding road density. There was no overall decline in predation attempts with increasing paved road density, or increase in predation attempts with increasing distance to the nearest paved roads. However, we cannot rule out the predation release hypothesis for larger mammalian predators, as they were not well sampled in our study. For predatory birds, we found weak evidence in support of the predation release hypothesis, but this conclusion is very tentative, as we only recorded three predation attempts by birds. We suggest that the predation release hypothesis for positive road effects on small mammals merits further investigation, using methods tailored to the particular predators most likely to impact small mammal populations.

Some authors have hypothesized that observed increases in small mammal populations with increasing road density (after controlling for habitat effects) may be due to predation release. Predation, especially predation by birds, could be reduced in areas with high road density, because of negative effects of roads on predator numbers and/or hunting activity. However, there are no studies testing the relationship between road density and predation rate on small mammals. Based on the predation release hypothesis, I predicted that Peromyscus leucopus placed in sites with higher surrounding paved road density and/or closer to a paved road would experience fewer predation attempts than P. leucopus placed in sites with lower surrounding paved road density and/or farther from a paved road. Considering all predators, there was no evidence of any decrease in predation attempts in relation to paved road density, but the credible interval was wide, and the possibility of a biologically relevant increase could not be ruled out.Considering only raptorial birds there was evidence of a decrease in predation attempts with paved road density, and an increase with increasing distance from the road, as predicted.However, the number of raptors was small and this change was not observed for the more numerous specialist mammalian predators. Overall, these results provide at best weak support for the hypothesis that reduced predation, specifically by birds, causes the positive relationship between road density and small mammal abundance. III ACKNOWLEDGEMENTSI would like to start by thanking my supervisor Dr. Lenore Fahrig, for her support, guidance and most importantly patience throughout the course of my project. Your knowledge and expertise enabled me to excel at all tasks and kept me encouraged throughout. Thank you for the time and funding that you have put into my project, being part of your lab has been an incredible experience.