Batty Schemes

Many of the UK's native bats are sadly threatened by loss of their habitats, and the spread of the road network. Many bats fly at low height, and so a very vulnerable to being hit by vehicles as they cross roads. This has lead to the creation of "Bat Bridges" over several new roads in the UK. These are made from wire mesh or steel girders and were believed to appear to the bats' sonar as similar to  hedgerows and other natural features which bats tend to use as navigation aids. Following the bridges would hopefully induce the bats to fly at a safe height above the road.

A bat bridge was recently built across the new Porthmadog by-pass at a cost of £650,000 to the tax payer. This has proven controversial with local residents, who would have preferred the money be spent on a foot bridge so that children and the elderly could safely cross the road to access local walking routes.

To add to the controversy, a study by Leeds University has concluded that the bridges are ineffective. The bats do not seem to recognise the artificial structures and instead ignore them, continuing to use their old routes which puts them in harm's way when they cut across roads.

The paper’s lead author, PhD student Anna Berthinussen, said: “Many bat species forage up to several kilometres from their roost, so our road system is an ever expanding network of life-threatening hurdles the bats must overcome. Our findings raise concerns about how we can build or improve roads without impacting on these protected species. We need to find solutions that really work and suggest that alternative designs are investigated and, most importantly, tested more effectively than they have been in the past.”