Between Risk and Refuge: Anthropogenic Linear Features Serve as Barriers, Corridors, and Habitat for Eastern...

Urbanization creates vast human-altered landscapes effectively isolating remaining pockets of habitat and introducing linear anthropogenic features such as roads and utility corridors. These features may function as barriers, corridors, or habitat, potentially in unexpected ways. We investigated the spatial ecology of eastern copperheads (Agkistrodon contortrix) in a suburban nature park in the St. Louis metropolitan area (Missouri, USA) to determine the extent that roads, paved foot trails, and powerline clear cuts influence movement and habitat selection. Using radiotelemetry, we tracked 14 adult snakes (7 males and 7 females) over six active seasons (2018-2023), collecting 1950 relocations. Random path analyses, step selection functions, and context-dependent movement models uncovered an apparent paradox; snakes of both sexes avoided crossing roads at all spatial scales, yet preferred roadside habitat. Both sexes also selected for foot trail crossings and occupancy of powerline clear cuts, potentially utilizing these features for improved foraging habitat, thermoregulatory opportunities, and refugia. Additionally, males moved further per step than females, but there was no difference in movement probability between the sexes. Snakes' odds of moving were 46% lower when occupying roadside habitat and 2.3 times higher when occupying powerline clear cuts, suggesting differing behavioral states within, and functions of, these habitats. Our findings suggest that linear anthropogenic features can simultaneously act as barriers, movement corridors, and preferred habitat, underscoring the need to determine whether such features provide genuine benefits or function as ecological traps for wildlife occupying urban landscapes.