Every year, hundreds of thousands of bats are killed by flying into the giant blades of wind turbines. It is one of the leading causes of bat mortality in North America and Europe, according to Bat Conservation International. However, the reasons for these fatal collisions are largely unknown. One possibility examined by a new study published in Biology Letters is that they may be attracted by light reflected off the blades, much like when moths make a beeline for a flame.
This idea is based on how bats navigate. The flying mammals use the open sky to help them find their way while flying. Kristin Jonasson, an independent physiological ecologist, believes that at dawn and dusk, the giant turbines may reflect just enough light to appear as a clear opening in the sky. This could trick the bats into flying directly toward the spinning blades.
To test this hypothesis, Jonasson and colleagues at the University of Colorado Colorado Springs, National Renewable Energy Laboratory and the U.S. Forestry Service flew 242 hoary bats (Lasiurus cinereus) and 154 silver-haired bats (Lasionycteris noctivagans) through a dark Y-shaped maze with two different exit options.