Analysis of Mammal Usage Relative to Compliance Rates of Wildlife Crossing Structures in South Korea

Abstract

A total of 564 wildlife crossing structures have been constructed in South Korea to restore fragmented ecological corridors and reduce roadkill. This study investigates whether these wildlife crossing structures comply with the “Guidelines for the Installation and Management of Wildlife Crossing Structures.” The subjects of this study were 366 overpasses and 198 underpasses in South Korea. Overpasses were assessed based on nine criteria, while underpasses were evaluated using eight criteria. Among the overpasses, the compliance rate for topographical connectivity was the highest (65.6%), followed by the compliance rate for the installation of wildlife fences in both directions (59.0%). However, most fences were poorly extended (29.0%), and showed poor connectivity, with open gaps (14.5%). For underpasses, the highest compliance rate was for fences installed in both directions (58.1%), followed by topographical connectivity (57.6%). Yet, most fences were inadequately maintained (16.7%), and openness did not exceed 0.7 (16.7%). Overall, the compliance rate for overpasses was 41.1%, while underpasses had a compliance rate of 38.3%. The average number of mammal species using overpasses with average compliance rates above 41.1% was 1.90, while overpasses with compliance rates below this threshold had an average of 1.17 species. For underpasses, the average number of mammal species was 1.49 for structures with compliance rates above 38.3%, compared to 0.91 for those below this threshold. These findings indicate a difference in the number of mammal species using wildlife crossing structures based on their compliance rates. Efforts to enforce compliance with the guidelines are necessary to enhance the effectiveness of wildlife crossing structures, and legally mandating these guidelines may be a practical solution.