Master of Science (MS)
Semester of Degree Completion
Stephen J. Mullin
Various structures have been integrated into roadways to ensure the road does not impede wildlife movements between adjacent habitats. Where traffic volume is low, the costs of installing and maintaining such structures is typically prohibitive. I tested the efficacy of a hose-bridge deployed temporarily on a State Park road in Illinois that allowed the passage of cars over it and small wildlife species to cross through it. I predicted that, during the 4.5 -week period of peak migratory movement, road-based mortality of Dekay's Brownsnakes (Storeria dekayi) would be less at the site having the hose-bridge, when compared to a similar section of road without a hose-bridge (control). I erected drift fences at both sites to guide snakes to each section of road and collected snakes that successfully crossed the road with an array of cover objects and pitfall and funnel traps. The speed limit on the road varied from 32-48 kph, but cars passing over the hose-bridge slowed to ≤8 kph. Snake mortality at the hose-bridge site was reduced compared to the control site. Mortality at both sites was less than in previous years, which might be attributable to reduced vehicle speed or increased motorist awareness of migrating wildlife. I conclude that the hose-bridge and accompanying signage efficiently decreased the road mortality of Storeria dekayi during their fall 2014 and 2015 migrations.
Manka, Sarah Elizabeth, "Assessment of the Efficacy of the Hose-Bridge as a Road-Crossing Structure for Dekay's Brownsnake (Storeria dekayi)" (2016). Masters Theses. 2442.