What attributes are relevant for drainage culverts to serve as efficient road crossing structures for mammals?

• Published in: Journal of environmental management 2020-08, Vol.268, p.110423-110423, Article 110423
• Main Authors: Brunen, Benjamin, Daguet, Caroline, Jaeger, Jochen A.G.
• Format: Article
• Language: English
• Subjects: Mitigation measures; Road ecology; Road mitigation; Track boxes; Underpasses; Wildlife cameras; Wildlife passages
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.110423

Roads increase wildlife mortality and present a movement barrier for many species. While wildlife passages have been advocated as a solution to many of the problems associated with roads, they are expensive and many roads still have none. However, roads usually have a series of drainage culverts designed to allow water to cross underneath the road, which might also be used by some mammals. This study aims to (1) determine what variables influence the number of successful passages of drainage culverts by mammals, and to (2) parse the effects that these variables have on the entry into and subsequent full passage of drainage culverts by individual mammals, using cameras and animal track stations along a 20 km stretch of autoroute 10 in Southern Quebec (Canada). Overall, 20 species were observed outside of the drainage culverts, but only about half of them were detected making full crossings. While various species were often seen outside, only animals highly tolerant to water, including raccoons (Procyon lotor) and American mink (Neovison vison), were observed fully crossing the structures with regularity, whereas the number of full crossings was small (