Action: Install hop-overs as road crossing structures for bats
Key messagesRead our guidance on Key messages before continuing
- We found no studies that evaluated the effects of hop-overs as road crossing structures for bats on bat populations.
‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.
A ‘hop-over’ typically consists of tall vegetation planted on either side of a road with overhanging branches that create a continuous canopy over the road gap. The aim is to guide bats across roads at a safe height above traffic. There is evidence that bats will cross roads at greater heights in the presence of high canopy cover or roadside embankments (Russell et al. 2009, Berthinussen & Altringham 2012). However, experiments using two parallel screens at natural gaps in bat flight paths in Denmark had mixed results, with some bats continuing to fly at hazardous heights or abandoning their commuting routes (Christensen et al. 2016).
Berthinussen A. & Altringham J. (2012) Do bat gantries and underpasses help bats cross roads safely? PLoS ONE, 7, e38775.
Christensen M., Fjederholt E.T., Baagøe H.J. & Elmeros M. (2016) Hop-overs and their effects on flight heights and patterns of commuting bats – a field experiment. SafeBatPaths Technical Report. Conference of European Directors of Roads (CEDR), Brussels.
Russell A.L., Butchkoski C.M., Saidak L. & McCracken G.F. (2009) Road-killed bats, highway design, and the commuting ecology of bats. Endangered Species Research, 8, 49–60.