Bats are being put in danger by the increasing number of wind turbines in Lincolnshire, it has been claimed.
Some conservationists have said turbines in the US and Europe have had a serious impact on bat populations.
The Bat Conservation Trust has called for talks with the renewable energy industry for more research ahead of more wind farms being built.
But the local Green Party dismissed the idea saying there was no evidence impact was significant.
Simon Mickleburgh from the trust said Lincolnshire was a wind farm hotspot and also had 11 of the 17 UK bat species.
However he admitted it was not clear why bats were falling victim.
"It could be that the turbines are confusing their sonar systems so they can't take avoiding action.
"There is also an idea insects are attracted to the warmer turbines, which in turn brings the bats in close."
But Martin Deane from the Green Party rejected the idea.
"There are some reports of birds being killed by wind farms but only a handful - against 75 million birds a year killed by cats in the UK.
"So deaths caused by turbines have to be set against the benefits of renewable energy."