"This raises the possibility that radar could be used to deter bats from approaching wind turbines. And so far this would appear to be the only real possibility of preventing bats colliding with turbine blades worldwide," says Professor Racey. "People are aware of bird deaths at wind farms but are not so aware that many bats are perishing too." He adds that bat fatalities at wind turbines have been logged in Australia, North America, Germany, Spain and Sweden, but the scale of the problem in the UK has yet to emerge as the area is largely unstudied.
Racey explains that the research was sparked by a chance anecdote from one of the university's honour students who was studying bats in Aberdeenshire some years ago. When driving back to Aberdeen, the student would wedge his bat detector in the window of his car to listen for bats. Every time he passed the Aberdeen Airport radar he could never hear any. "We think that bats either feel the heat of the radiation or can actually hear it," says Racey. "Either way, they appear not to like it and forage elsewhere."
Racey points out that three years ago nearly 3000 bats were killed in a six week period at one wind farm in the United States and nearly 1700 were killed over a same period of time at another US wind farm. Three species of bats are causing concern in the US and one of them, the red bat, is seriously threatened. "Bats migrate along ridge crests and these crests are also ideal locations for wind turbines, so we are concerned that if the killing continues more species of bats could end up becoming endangered," he says.
Racey and Nicholls are calling for further studies to determine the characteristics of radar which best deters the bats. Their research is published in the Public Library of Science Journal.