Wind Energy Turbines Killed More Than 600,000 Bats in 2012

Wind power holds the promise of clean energy for the future, replacing methods that are more damaging to the environment and release carbon dioxide. Yet this energy needs to be harvested somehow, and wind turbines are the most effective method. Now, a new study has revealed that these turbines may be deadlier than expected. It turns out that more than 600,000 bats were killed by wind energy turbines in 2012, a serious blow to creatures who pollinate crops and help control flying insects.

"The development and expansion of wind energy facilities is a key threat to bat populations in North America," said Mark Hayes, one of the researchers, in a news release. "Dead bats are being found underneath wind turbines across North America. The estimate of bat fatalities is probably conservative."

In order to assess the impact of wind turbines on bats, the researchers analyzed data on the number of dead bats found at wind turbine sites. Bats can be killed when they fly into the towering turbines, which spin at up to 179 mph with blades that can stretch 130 feet. Earlier estimates of bat deaths ranged from 33,000 to 880,000, so it was crucial to find out exactly what the number was.

"A lot of bats are killed because the turbines move at low wind speeds, which is when most bats fly around," said Hayes in a news release. "In a recent study in Pennsylvania, researchers adjusted the operating speeds from 10 mph to 18 or 20 mph and decreased fatalities by 40 to 90 percent. I am not against wind energy. It's clean, it reduces pollution and it creates jobs. But there are negative impacts. Still, I think this is a problem we can solve."

In fact, the estimate of 600,000 could be conservative. When a range of fatality estimates were reported at a wind facility, the researchers always chose the minimum estimate. Also, the number of deaths was estimated for just migratory periods rather than the entire year. This means that it's very likely that the number could be as high as 900,000.

Needless to say, it's important to understand how this mass of deaths will impact bat populations. It also shows that steps are needed to reduce the amount of deaths in the future.

The findings are published in the journal BioScience.