Wind turbines’ affect on bats is considered

Endless Energy Corp. of Yarmouth, Maine, wants to build five 390-foot wind turbines on the ridgeline of Little Equinox Mountain. Several biologists from the state and the company will discuss the project’s ecological issues with the Planning Commission at a public hearing Monday.

Both the Indiana bat and the Eastern small-footed bat, which are endangered species, live and hibernate in southwestern Vermont.

Wind energy projects in West Virginia and Pennsylvania have killed thousands of bats, said D. Scott Reynolds, a biologist with North East Ecological Services working for Endless Energy.

Now, he said, biologists need to determine if the current project would also be dangerous for bats.

"We need to find out how many bats we’re hearing or seeing within the airspace occupied by the turbines," Reynolds said during an interview on Tuesday. "But there was no obvious mortality for bats at the earlier wind projects on Equinox, and none at the current facility in Searsburg."

Harley Lee, the president of Endless Energy, said the company has installed microphones on the ridgeline that measure bat chirping.

Between 99 and 100 percent of the bat chirps came from areas that would be lower than the turbine blades, Lee said, because the bats apparently travel close to the ground or the forest canopy.

Reynolds added that the bats were flying at a "surprisingly low" height.

Scott Darling, a biologist for the state Department of Fish and Wildlife, said that reasons for dead bats near wind turbines in the eastern United States remain unknown.

"As wind turbine development occurred, many sites began noticing dead bats," Darling said. "The whole issue took bat biologists by surprise."

He said ridgetop wind turbines in forested areas might increase bat mortality, but scientists don’t know for sure.

"We have some data collected by the wind farms," he said. "But we don’t really know why the wind turbines have had this impact."