Bats are being slaughtered by giant wind turbines, warns new research.
Pipistrelle bats are much more active around wind farms than other places – putting them at severe risk, say scientists.
It appears the animals are attracted to the spinning devices on warm nights like moths to a flame.
Scientists do not know why, but think it could have something to do with the machines themselves or the large number of insects flying around in the air.
Common pipistrelle bats account for more than half of all bat fatalities at turbine sites across Europe, say researchers.
Lead author professor Fiona Mathews at the University of Sussex said: “Bat activity at wind farms is very variable.
“During periods of high wind speed, when most energy is generated, bat activity is low and so there is little risk to bats.
“In contrast, there can be high activity at turbines on nights with light winds and warm temperatures.
“Most of the attraction to turbines appears to be happening on these high activity nights.”
While most energy farms are built in locations where bats are not common, they appear to be drawn towards them.
Bat activity was monitored at 23 British wind farm sites and other locations without turbines.
Activity in places where a wind turbine was present was around a third higher than elsewhere, the researchers found.
Also, two thirds of high activity cases were recorded in these places.
Why remains a mystery, but could have something to do with the machines themselves, the researchers say.
Alternatively, the 280 foot turbines could be attracting large numbers of insects for the bats to feast on.
Professor Mathews added: “We have worked with the Statutory Nature Conservation Organisations and industry to produce guidance to help minimise the risks to bats.
“These include stopping blades rotating when no energy is being produced, also known as idling.
“This is a win-win situation as little electricity generation is lost during these periods.”
Soprano pipistrelle bats, a different species, were not more active in places with wind turbines, the researchers found.
Guidelines for energy companies have been drawn up to help reduce the number of flying fatalities.
A turbine’s blades are usually around 120 feet long and can spin at speeds of 120 miles per hour.
Whether bats get too close depends in part on the weather conditions, according to the researchers.