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Providing evidence to improve practice

Individual study: Movement re-established but not restored: Inferring the effectiveness of road-crossing mitigation for a gliding mammal by monitoring use

Published source details

Soanes K., Lobo M.C., Vesk P.A., McCarthy M.A., Moore J.L. & van der Ree R. (2013) Movement re-established but not restored: Inferring the effectiveness of road-crossing mitigation for a gliding mammal by monitoring use. Biological Conservation, 159, 434-441


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Install pole crossings for gliders/flying squirrels Terrestrial Mammal Conservation

A replicated, site comparison study in 2007–2011 along a highway in Victoria, Australia (Soanes et al. 2013) found that glider poles, along with canopy rope bridges across highways, were used occasionally by squirrel gliders Petaurus norfolcensis. Just one of seven radio-tracked squirrel gliders crossed the road where a glider pole was present compared to three of seven crossing canopy road bridges. Seven of 10 crossed a narrow single-lane-road without crossing structures but none of 12 crossed a wider highway with no crossing structures. Camera traps recorded 13 crossings by squirrel gliders at glider poles over 146 camera-trap nights. In July 2007, three glider poles and two rope bridges were installed along a 70-km-long section of four-lane divided highway. Poles (13 m high, 45 cm diameter) were installed in the centre of the highway to reduce glide distances required for road crossings. Camera traps monitored pole use (December 2009–March 2011; 22–87 nights/pole) and rope-bridge use (August 2007–May 2011; 787–873 nights/bridge). In 2010–2011, 42 gliders were radio-tracked at sites with and without crossings and at a narrow (<10 m wide) single-lane road.

(Summarised by Rebecca K. Smith & Nick Littlewood)

Install rope bridges between canopies Terrestrial Mammal Conservation

A replicated, site comparison study in 2007–2011 along a highway in Victoria, Australia (Soanes et al. 2013) found that canopy rope bridges across highways, along with glider poles, were used by squirrel gliders Petaurus norfolcensis. Three of seven squirrel gliders crossed roads when canopy bridges were present. The proportion of squirrel gliders crossing roads where canopy bridges or glider poles were installed (29%) was higher than that which crossed roads when such structures were absent (0%). However more still (70%) crossed at a narrow, single-lane road with low traffic flows and no artificial crossing structures. Camera traps recorded 1,187 crossings at canopy bridges. It took 9–13 months for gliders to habituate to and use bridges. In July 2007, two rope bridges and three glider poles were installed at five sites along a 70-km-long section of a four-lane divided highway. Canopy rope bridges were 70 m long, 0.5 m wide and 6 m high. Camera traps monitored bridge (August 2007–May 2011; 787–873 nights/bridge) and pole use (December 2009–March 2011; 22–87 nights/pole crossing). In 2010–2011, 42 gliders were radio-tracked at sites with and without crossings and at a single-lane-road site (<10 m wide).

(Summarised by Rebecca K. Smith & Nick Littlewood)