Restoring Connectivity in Landscapes Fragmented by Major Roads: A Case Study Using Wooden Polesas "Stepping Stones" for Gliding Mammals

Abstract

Tree-dwelling mammals may be vulnerable to road mortality if forced to cross canopy gaps on the ground. This group of mammals has received scant attention worldwide despite major road projects potentially causing severe fragmentation to their habitat. Gliding mammals may be enabled to cross road gaps that exceed their gliding capability by the installation of tall wooden poles to act as "stepping stones."We investigated whether such glide poles installed across two land-bridges in eastern Australia could restore landscape connectivity for small gliding petaurid marsupials. Hair-traps revealed repeated use of all poles at both locations over periods of 1-3 years. Camera traps at one site suggest a crossing frequency on the poles by the squirrel glider (Petaurus norfolcensis) of once every 3.8 nights. Radio-tracked animals did not glide directly over the road but instead used the poles to cross on the bridge. Hair-traps and camera traps installed within the middle of two reference land-bridges that lacked glide poles failed to detect crossings by gliding mammals despite their presence in adjacent forest. These observations suggest that glide poles can facilitate road crossing and thereby restore habitat connectivity for gliding mammals. This lends support to the notion that glide poles have the potential to mitigate road-induced habitat fragmentation for gliding mammals worldwide.