Project aim:
In this study, we - together with ANUVA GmbH - investigated whether and to what extent the road-crossing aids for bats installed on roads in Germany fulfill their function.
To this end, the behaviour of bats was recorded both visually and acoustically with self-developed recording devices at nine road-crossing aids (fences).
In addition, the large-scale behaviour of the bats was investigated using automated telemetry in the vicinity of a crossing aid.
Results - short & sweet
The effectiveness of the crossing aid (reduction in the proportion of all road crossings that occur at an unsafe height) averaged 50 % across the sites and species.
Whether a bat crossed the road at an unsafe height was significantly influenced by
the location of the crossing at the crossing aid, the direction of flight (towards the road
or away from the road) and the starting height of the crossing.
In addition, species-specific differences in behaviour became apparent. In addition, site-specific parameters (traffic density, road width) also influenced the behaviour
In summary, the results of the study show that the type of crossing aids investigated can help to
reduce the risk of collision for bats
Depending on the conflict assessment, a combination with other measures (e.g. green bridges)
may be necessary to sufficiently reduce the risk of bat mortality.
The complete report is available for free Download ↗ (partly only available in German).
Author team & sponsors
The project was financed and supervised by the Federal Highway Research Institute (BASt).
The report was prepared in co-operation with ANUVA GmbH.
