Road Ecology Center
Measuring the Success of Wildlife Linkage Efforts
- Author(s): Servheen, Christopher
- Shoemaker, Rebecca
- Basting, Pat
- et al.
Successful movement of wildlife across highways to effectively provide population-level wildlife linkage is usually viewed in one dimension - movement either exists or it does not. We believe that there are multiple ways to measure both the existence and value of such movement opportunities to better demonstrate success or failure of these efforts. The use of multiple methods to measure success will provide quantitative and qualitative values that can be used to better judge the effectiveness of wildlife movement across highways and to justify investment in the in¬frastructure to create such movement. Currently, many transportation agency administrators view investments in wild¬life crossing infrastructure as outside their responsibility and as fiscal competition for highway projects of greater value to the traveling public. We believe this is a false paradigm that can be changed by enhanced measures of the values of wildlife highways crossing enhancement. Measures of success should include a wide range of factors that transcend wildlife issues. These factors should include biological impacts; economic impacts on highways, public lands, and private lands; public safety measures; social influences and acceptance; and political factors. Biological measures of success should include wildlife movement, gene flow measures, seasonal range access and dispersal opportunity, potential for re-occupancy of historic habitat, reduction in population isolation, effects on endangered species listing and management, and mortality reduction. Economic successes should include improved project planning efficiency, reductions in project time delays, reduced environmental review and court challenge costs, and improved land values adjacent to linkage areas due to healthy wildlife populations. Public safety measures should include road kill reduc¬tion, reduced probability of accidents and human injury, and improved speed limits. Social measures should include attitude surveys measuring public willingness to invest public funds to reduce wildlife collisions, public acceptance of the concept of linkage zones, and public awareness of the multiple benefits of wildlife population connectivity. Political measures should include measuring the knowledge and understanding of this issue by political interests, their willing¬ness to appropriate funding for such projects, and legislation. We review the application of each of these measures of success to wildlife crossing enhancement and suggest a basic measurement approach to all wildlife crossing efforts. In the long term, successful wildlife linkage efforts associated with highways will require improved public understand¬ing and support, improved agency willingness to accept wildlife crossings as part of their responsibility, and improved understanding of the multiple values and benefits that come from enhancing wildlife movement across highways.