Providing safe wildlife passage across roadways has become increasingly common in the western United States over the past 30 years. New Mexico first began implementing wildlife crossing projects in 2003. Since then, ten wildlife crossing mitigation projects have been constructed across the state. However, the effectiveness of these mitigation projects in reducing wildlife-vehicle collisions and providing safe wildlife passage was never rigorously evaluated. In 2016, the New Mexico Department of Transportation (NMDOT) Research Bureau, with the help of the Arizona Game and Fish Department, and in collaboration with New Mexico Department of Game and Fish (NMDGF), began a two-phase study of select NMDOT mitigation projects to evaluate their effectiveness and identify potential shortcomings. Phase I (completed early 2021) examined crossing structure use by wildlife and attempted to pinpoint factors that might influence usage. Trail cameras stationed at sixteen crossing locations (including two at-grade), three game fence gates, and one game guard across four study areas captured more than 1.25 million images of 21 different species. There were 14,242 use events documented at the crossing locations. Phase I results determined that, when operating as intended, the observed structures helped facilitate movement of wildlife across roadways and dramatically reduced wildlife-vehicle collisions (WVC). Phase II of the study (beginning 2021) will see the continuation of data collection from Phase I as well as include additional project locations. Phase II will also conduct an in-depth analysis of driver response to an existing Animal Detection System near Cuba, NM. The information provided by this research is critically important in determining the success of previously implemented wildlife crossing projects and will help guide future mitigation efforts. New Mexico is poised to implement numerous additional crossing projects since the passing of the 2019 Wildlife Corridors Act, the first of its kind in the nation. The Act tasks NMDOT, along with NMDGF, to create a Wildlife Corridors Action Plan that identifies areas hindering landscape-scale wildlife movements and roadway segments that are prone to exceptionally high numbers of WVC. The Action Plan will use a two-pronged approach in identifying priority project areas. First, hotspot analysis will identify areas of high WVC. Second, ecological modeling will identify where predicted wildlife linkages cross roadways. A priority project list will identify the top five WVC hotspots and the top five ecological corridors. A draft Action Plan will be published for public comment mid-2021 and is anticipated to be finalized by the end of the year.
Wildlife movement: connectivity, safety, across eco-tones