Roads are associated with a blunted stress response in a North American pit viper

Whereas numerous studies have examined roads as anthropogenic stressors in birds and mammals, comparatively few studies have been undertaken on reptiles. We investigated plasma corticosterone (CURT) levels at baseline and following 30 min of restraint stress in free-ranging copperhead snakes (Agkistrodon contortrix) captured within the forest interior or while in contact with public roads. There was no difference in baseline CURT levels between snakes in the forest and on roads. Copperheads responded to restraint stress by increasing plasma levels of CURT; however snakes on roads exhibited a lower CURT stress response compared to forest snakes. Additionally, among snakes captured on roads there was a negative association between road traffic and baseline CURT, stressed COAT, and the magnitude of the CURT response. Our results suggest that roads are associated with a blunted stress response in copper-heads. Reduced stress responses may be indicative of acclimation, the inhibited ability to mount a stress response in the face of prolonged chronic stress, or that road environments select for individuals with lower CURT responsiveness. Either scenario could result in increased road mortality if snakes do not perceive roads as a potential threat. (C) 2014 Elsevier Inc. All rights reserved.