Wildlife Road Mortality on Two Roads Bordering Vernal Wetlands

Elias Rackoff

Biology

Rebecca Hale

Habitat fragmentation, caused by roads or other human-made structures, can reduce the abundance of various species by preventing animals from moving normally through their habitat. Populations can be separated from each other, and animals can be blocked from moving between their typical breeding, foraging, and hibernation locations. Amphibians are at especially high risk from fragmentation by roads because they are small, difficult to see, frequently move at night, and occasionally participate in mass migrations. Under-road wildlife passages can reduce incidence of amphibian mortality; however, building effective passages requires knowing where along roads migrations are likely to occur and funneling animals toward the passages. Sandy Bottom Preserve is a protected area in Buncombe County, NC containing several vernal pools, streams, and permanent ponds that host a wide range of amphibians, birds, reptiles, and other small vertebrates. The Preserve is divided by two roads, Parkway Crescent, and Sandy Springs Dr., that are known to have high incidence of road mortality. The purpose of this project was to quantify road mortality in order to inform the placement of a wildlife passage on each road. I surveyed a 350 m stretch of each road and recorded all instances of vertebrate mortality, biweekly for 25 weeks from the late spring to early fall of 2022. The two roads differed greatly in specimen number: Parkway Crescent had 67 specimens while Sandy Spring Rd. had only 21. Salamanders were the most common clade, with Notophthalmus viridescens being the most common species. There were several areas with high concentrations of specimens on Parkway Crescent, such that no single location for the under-road passages stood out. If two passages can be built, I suggest that they both be placed under Parkway Crescent, with fences along both sides of the road to direct animals toward the passages.

Jan-9-2024