As a child, I loved bats. They often came out at sunset, all at the same time, from the caves on the other side of the river. They cut a magnificent sight, with the darkening sky as a backdrop. I have always thought bats are creatures of mystery, and I totally understand my Native American ancestors who saw them as messengers from the spirit world. But now, bat populations everywhere are being decimated by a combination of threats they have no defense against. For instance, there's white-nose syndrome in the northeastern and eastern United States. And now, bats are turning up dead in the vicinity of wind farms. The number of fatalities is appalling.
For several years, ecologists and other researchers have been trying to decipher the causes of this new disaster. Recently, the University of Wisconsin-Madison launched a study funded by a renewable energy company in southeastern Wisconsin. The findings shed light on what exactly is killing these bats, and they also suggest a potential solution - provided we humans are willing to work out the details.
The scientists from UW-Madison concluded that bats often collide with the turbines at the wind farms. These collisions cause fractures and internal injuries that invariably lead to death. Other times, the spinning of the turbine blades creates areas of different air pressure, which result in physical trauma as the bats attempt to navigate them.
The combination of these two factors is exacting a heavy toll on the bat population - and we might even be underestimating its true extent. Many of the dead bats near the wind farms had suffered crippling damage to their eardrums. Without healthy eardrums, it's much more difficult for these beautiful animals to hunt or orient themselves. It's possible that many of them, not as badly injured, could have flown away from the turbines but died later on anyway, from exhaustion or starvation.
If this is the case, the bats' salvation is in our hands. New, more environmentally conscious designs for our wind turbines could improve the bats' chances for survival. We could also find ways to solve our energy problems that are less intrusive in the bats' territory. In other ways, we could find better ways to coexist. The question is, do we have the will or the ability to do it?
For the sake of the bats - and ourselves - I certainly hope so.