Abstract

Roads and traffic negatively impact many wildlife populations and ecological processes because they act as barriers to the movements of animals, reduce habitat accessibility, and reduce habitat quality next to the road. These limitations can affect an animal’s migration pattern, its access to resources, it mortality rate, gene flow, and the dispersal opportunities for the young. Roads also have several effects on the level of populations, such as changes in predator-prey relationships, decreases in species richness, and overall community composition. However, many of these higher-level effects have a response delay, therefore predicting their magnitudes can be difficult. For this reason, long-term monitoring projects are essential to arrive at more accurate impact predictions in the future. In addition, mitigation measures are needed to reduce a road’s impacts on wildlife populations.

This research project will determine whether the passageways are effective for medium-sized and small mammals and whether further road management is needed. The effectiveness of the mitigation measures for large mammals has been studied in a separate project. This four-year project will provide important information for adaptive management and long-term monitoring of road mitigation.
This research project has three main objectives:

1. To characterize the locations and rates of vehicle collisions with small to medium-sized mammals and to evaluate the difference in the frequency of highway- related mortality between areas of the highway with mitigation measures and areas without.

2. To determine the performance of the four types of passages for small to medium-sized mammals.

3. To assess how well the mi;ga;on measures provide for the permeability of the highway for individuals and for gene flow across the road, with a focus on the American marten.