Bats face many different threats in the UK, from cat attacks to disease and loss of habitat. As if things weren’t tough enough for these echolocating creatures of the night, it turns out that wind turbines are also out to get them, and ecological protection assessments are failing to stop it.
Hundreds of bats are killed each month in the UK after having unfortunate run-ins with wind turbines, according to a new study published in Current Biology. The researchers from the University of Exeter looked into 29 onshore wind farms across the UK. Using dogs to sniff out unlucky dead bodies of fallen bats, they found that at least 194 bats were killed nationwide each month. Some individual winds farms had as many as 64 bat fatalities per month.
“Bats have been around for at least 30 million years and during that time have been able to fly happily without the risk of colliding with a spinning object. They may even ‘switch off’ their sonar at the height of turbines, because they are not used to encountering objects at that altitude,” Dr Fiona Mathews, a mammalian biologist on the project, said in a statement.
Stories of this ongoing bat massacre are nothing new. However, the researchers say the real crux of their project is showing how current ecological impact assessments aren’t doing their jobs. This is particularly bad news for bats, of which all species are protected by law in the UK.
“There are effective ways of preventing bat deaths,” Dr Matthews added. “Unfortunately we have found that assessments conducted when wind farms are being planned are very poor at identifying whether a site is likely to be risky. This means that appropriate action is not taken to protect bats.”
One of these ways is simply reducing the speed of the turbines' rotation during the night in summer and early fall when bats are most active.
Of course, none of this is to say that wind farms are a terrible thing either. All things considered, wind farms are still a vastly positive thing for the environment and wildlife.
Dr Paul Lintott, lead author of the study, explained: “Although bats are killed by wind turbines it is important that this is put into context alongside the many other causes of bat mortality caused by humans including collisions with vehicles, kills by domestic cats, and range contraction due to climate change.
“Our findings demonstrate that costly pre-construction surveys are relatively poor at predicting if bat casualties will occur. However, by focusing resources on stopping turbines during high-risk periods we should be able to minimise the collision risk to local bat populations whilst also benefiting globally from the transition to a greener economy.”