AlbertaWind Farms Prove Deadly For Bats
Margaret MunroCanwest News Service
Monday, August 25, 2008
Air pressure changes caused by wind farms are killing large numbers of bats, say biologists who are studying the tiny corpses falling out of the sky near turbines in southern Alberta.
They say the bats' lungs over-inflate as air pressure drops near the fast-spinning turbines bursting blood vessels and capillaries.
"Their lungs fill with fluid and they can no longer breathe," says Erin Baerwald, of the University of Calgary, lead author of a report on the bat deaths released Monday by the journal Current Biology.
Baerwald, whose team checks for carcasses under turbines at the Summerview wind farm near Pincher Creek, Alta., every morning, says bats are one of the unforeseen casualties in the rush to harness wind power. Several thousand of the tiny flying mammals are killed by the turbines each year across North America, with some farms much more deadly than others.
Industry officials say they are determined to reduce the death toll but concede it is not going to be easy since so little is known about the nocturnal creatures.
"It's a huge challenge," says Jason Edworthy, director of stakeholder relations for TransAlta Wind, which operates Summerview where close to 700 bats die each year. The Mountaineer Wind Energy Center in West Virginia is even more of a problem, killing as many as 1,800 of the bats a year, most during fall migration.
Bats, which are such good flyers they can pick tiny bugs out of the air at night, are inexplicably attracted to the giant towers and rotor blades that spin at speeds of up to 250 kilometres an hour.