Fatal Attraction: Wind farms a hazard to bats, birds, panel told…
Biologist testifies about wind farms’ impact on wildlife.
Flying into windmills may be more than just a deadly coincidence for bats - they may actually be attracted to the whirling blades.
This is the conclusion of a biologist who testified at a House Resources subcommittee hearing Tuesday, where lawmakers heard about many risks, but few solutions, where wind energy and wildlife mix.
Federal lawmakers are considering how to reduce the damage to bats and birds, possibly by tying wind energy tax credits to wildlife protection.
Bats are of particular interest in Northern New York, where federally protected Indiana brown bats complicate wind farm proposals in Jefferson County. The county is home to the northernmost colony of the endangered bats, which number about 2000 in the area, wildlife biologists estimate. Bats eat more than their weight in mosquitoes and other insects in a night.
Why bats would seek out wind farms is a mystery, said Edward B. Arnett, a conservation scientist with Bat Conservation International, who testified at the House Resources Subcommittee on Fisheries, Wildlife and Oceans. But he said they seem to congergate near them during mating season, which he said he knows because bats that are social only during mating season have been found dead in large numbers on wind farms.
If bats are attracted to wind turbines, that would make siting wind farms more challenging because an area without bats could pose a risk no one expected.
“It creates a conundrum,” Mr. Arnett said. “It’s a real problem for us.”
My Arnett had this observation as well: Bats, which rely on a sonar-like sense called echolocation to catch insects and maneuver in caves, can’t seem to pick up a signal from a whirling windmill, which turns as fast as 180 miles per hour. Yet they do pick up echoes from slowly moving blades and avoid them in flight.
Scientists are stumped so far about why that is true, Mr. Arnett said, because the bats’ skill is poorly understood. Biologists do not know exactly how bats receive signals from moving objects, but if they did, they might be able to protect them.
Indeed, the big blades themselves may not be the problem, but rather the whirling air, or vortices, they create, he said.
Ultimately, Mr. Arnett said, scientists may figure out a way to scare the bats off by jamming their echolocation. Researchers have yet to put such a system fully in place.
In Jefferson County, Indiana brown bats present a hurdle for PPM Atlantic Renewable’s proposed Horse Creek Wind Farm between Depauville and Gunns Corners. The project’s generic environmental impact statement notes that nearby forests may provide summer roosting areas for bats.
The company has said that it may have to apply to the U.S. Fish and Wildlife for an “incidental take permit,” which would cover the company in case bats fly into the turbines and are killed, and that it expects to study further the possible impact on brown bats.
Fish and Wildlife Service Director Dale Hall said the government needs to evaluate the long-term and cumulative effect of wind energy on wildlife. Land-based turbines approach heights of 450 feet, and offshore turbines in the ocean and possibly the Great Lakes will likely be taller, he said.
The U.S. Government Accountability Office found in 2005 that wind facilities in California, Pennsylvania and West Virginia have killed large numbers of bats and birds of prey.
Much of the regulation of wind farms is by state and local governments. The federal government has suggested voluntary measures to operators with limited results, Mr. Hall said.
“I think compliance is skethcy at best,” Mr. Hall said.
But lawmakers and witnesses at the hearing urged a greater federal role , including requiring wind farm owners to take measures to protect wildlife or risk losing federal energy tax credits. A bill to renew the tax credits is being considered in the House Ways and Means Committee.
”You really do need federal oversight if you’re going to have federal money,” said Michael Fry, director of birds and pesticides at the American Bird Conservancy.
Watertown Daily Times, May 7, 2007