Why are wind turbines killing Alberta's bats?

University of Calgary researchers are trying to understand why hundreds of bats are dying each year in Pincher Creek, inexplicably drawn to wind turbines.

Robert Barclay, a University of Calgary professor who heads up the bat study at the Summerview WindFarm inPincher Creek, Alta., believes bats may be attracted by the sound of turbines or simply don't use their sonar when they migrate.

"They can pick up minute little insects in the air when they're feeding, and these massive structures that the wind turbines present you would think would be no obstacle whatsoever," he said.

As part of the study, Erin Baerwald, an ecology student, hunts for dead and injured bats in Pincher Creek's turbine fields.

"Last year, more than 500 were found. This year, we're following a similar trend. And that's just this wind farm," Baerwald said.

Not endangered

The problem was first uncovered about three years ago when bats turned up dead at several wind farms in the United States. It is affecting two kinds of bats that migrate from Canada to the U.S. in the fall — hoary and silver-haired bats.

"Every bat I find, it keeps me going," she said. "Because what we are all working for here is to stop this."

Bats play a crucial role in the ecosystem. They eat their body weight in insects daily. Barclay says they're not endangered, but they reproduce very slowly.

"The population declines because of some disturbance or other factor. It is slow to recover, and that is a bit of a worry," Barclay said.

Industry looking for answers

The wind power industry is expected to grow tenfold in the next decade.

Wind energy companies say they're taking the bat problem seriously, paying for several studies, trying to figure out what to do.

"There has been lots of talk about whether it is possible to emit a certain sound or to change even the blade characteristics so that the bats' sonar works better," said Jason Edworthy, a spokesman with Vision Quest, the wind power division of TransAlta.

"Maybe a sound that makes the bats say, 'Oh, I don't want to go here.'"