Curr. Biol. 18, R695–R696 (2008)

Wind turbines are bafflingly bad for bats, the bodies of which are often found beneath their blades. Erin Baerwald and her colleagues at the University of Calgary in Canada think they know why: the pressure differential near the blades causes decompression sickness in the animals.

The team collected dead hoary bats (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans) at a wind facility in Alberta. During autopsy, they found that 69 of the 75 bats had suffered haemorrhaging in the chest or abdomen, even though 32 seemed to have no external injuries. The remaining six had an external injury but no evidence of internal bleeding.

Bats apparently encounter the lethal pressure change as they flit close to the turbine blades.