Wayne McDonald Effects of habitat fragmentation on the movement of small mammals in Banff National Park. email: waynem@ualberta.ca

Abstract: 

Animal movement in fragmented landscapes is affected by barriers that dissect the landscape and corridors that facilitate movement across otherwise inhospitable terrain.  To assess how animals respond to natural and artificial barriers and how they find and use corridors, I measured the return success and path characteristics of Microtenes that were relocated across the Trans-Canada Highway (TCH) and the crossing structures that have been constructed to improve the permeability of the TCH.  To assess how mice and voles perceive and respond to barriers, relocations were performed along the TCH (an artificial barrier), a forested strip in the median of the TCH (a natural barrier), and in the grassy verge parallel to the TCH (no barrier).  Individuals were less successful in crossing manmade, artificial barriers than natural barriers, indicating that artificial barriers may be less permeable to movement.  Additional relocations to determine the elements that promote crossing structure use focused on three attributes of crossing structures: structure size and composition, the presence of cover at the entrance to structures, and the distance animals will travel to use a structure.  Small mammals tended to prefer crossing smaller, metal underpasses that provided overhead cover.  This apparent preference for small mammals to use crossing structures that are most closely related to their body size and have sufficient cover to provide protection from predators may have implications for corridor efficacy for other animals as well.  Crossing structure efficacy declined as the distance from an animal's home territory increased, which may have important implications for the future placement of wildlife corridors in fragmented landscapes.

Red-backed vole	Fluorescent dyed vole

Fluorescent dye trail