Hundreds of millions of animals are killed every year by road traffic. It’s a sad statistic that Jochen Jaeger, associate professor of geography at Concordia University, Montreal, Canada, hopes to reduce. But rather than focus on a specific location, as most studies do, he and colleagues have taken a less-common approach.
Jochen and an international team of collaborators stepped back to re-examine the results of dozens of studies already conducted in countries around the world. They combined the data from many studies and analyzed them together, which allows for the discovery of more general relationships that hold across many locations. They focused on what prevention methods are most consistently useful. The results were recently published in the journal PLoS ONE.
Of the more than 40 prevention methods available, the researchers found that, overall, fences, with or without crossing structures, reduce roadkill by 54% when considering all species combined. Crossing structures had no detectable effect without fencing.
When large mammals were examined, the combination of fences and crossing structures led to a roadkill reduction of 83%, while animal detection systems (such as laser tripwires or radar) led to a 57% reduction.
The study also determined that expensive measures were much more effective than cheaper ones.
Equally important in this study is its potential to improve the quality and consistency of future research.
The researchers suggest reporting more carefully on how animals fare at “hotspots” at the end of fencing stretches. Many animals seem to move along the fence, cross the road at the end and get killed there. A different design of the fence-ends could help reduce this effect, but research about this idea still needs to be done in the future.
—Concordia University press release by Suzanne Bowness
April 17, 2017 NewTerrain.