Living on the edge: Habitat selection of two sympatric snake species at the northern periphery of their geographic range

Abstract

Southwestern Saskatchewan is home to a unique snake community consisting of several species at the northern edge of their geographic range. Animals at the periphery of their geographic range often experience extreme or unique selection pressures which may put these peripheral populations, and thus the entire species, at a greater risk of extinction. Eastern yellow-bellied racers (Coluber constrictor flaviventris) have been identified as a Threatened species in Canada, with their known range confined to two river valleys in southern Saskatchewan. Prairie rattlesnakes (Crotalus viridis), however, are a wide ranging pit viper abundant in southern Saskatchewan and Alberta. The considerable difference in abundance of these species may be due to the availability of preferred habitat, though the habitat use of these two species has not been well studied in Canada. Results from this study will provide new information on the habitat use of these species at the northern periphery of their range and contribute to the development of management strategies for these species and for this grassland ecosystem.