It is feared bat numbers could be threatened by wind farms

Bat deaths at wind farms are thought to exceed those of birds and it is feared some species could eventually become endangered if action is not taken.

Now researchers at Aberdeen University believe radar may be key.

They studied the behaviour of bats at radar installations and found they did not forage where electromagnetic radiation could be measured.

Bat experts Prof Paul Racey and Dr Barry Nicholls studied bats at various distances from 10 radar installations across Scotland.

We think the bats either feel the heat of the radiation or can actually hear it. Either way, they appear not to like it, and forage elsewhere

Prof Paul Racey

Aberdeen University

They said they found bats foraged where no radiation was detectable.

Prof Racey, of Aberdeen's school of biological sciences, said: "We found that the bats were deterred by the electromagnetic radiation emitted from the radar installations.

"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."

Chance remark

He explained: "People are aware of bird deaths at wind farms but are not so aware that many bats are perishing too.

"Bat fatalities at wind turbines has been documented in Australia, North America, Germany, Spain and Sweden but really the scale of the problem in the UK has yet to emerge as the area is largely under-studied.

"Three years ago nearly 3,000 bats were killed in a six-week period at one wind farm in the USA, and nearly 1,700 were killed over a same period of time at another wind farm.

Wind farms are on the increase across the world

"If bat fatalities continue this has the potential to be really serious. The problem is likely to get much worse with the proliferation of turbines, not just from large power companies erecting them, but private individuals doing so as well."

It was a chance remark that led Prof Racey and Dr Nicholls down the route of exploring radars as a potential deterrent to bats around wind turbines.

A student said when was driving to Aberdeen he would wedge his bat detector in the window of his car and listen out for bats.

He noticed that every time he passed the Aberdeen Airport radar he could never hear any.

Prof Racey said: "We think the bats either feel the heat of the radiation or can actually hear it. Either way, they appear not to like it, and forage elsewhere.

"What is needed now are further studies to determine the characteristics of radar which best deters the bats."

A paper written by Prof Racey and Dr Nicholls - Bats Avoid Radar Installations: Could Electromagnetic Fields Deter Bats from Colliding with Wind Turbines? - appears in the Public Library of Science Journal PLoS ONE.