GREENBELT - Lawyers for organizations opposed to a wind energy project in West Virginia said in federal court Wednesday that it could violate the Endangered Species Act by harming a rare species of bat.

The 124-turbine wind farm being built by Rockville-based Beech Ridge Energy would put the lives of endangered Indiana bats, and other bat species, in danger, according to the plaintiffs -- The Animal Welfare Institute, Mountain Communities for Responsible Energy and David G. Cowan.

Plaintiff's witness Michael Gannon, a bat biologist and professor at Pennsylvania State University, said he is "very much in favor" of wind energy, but remains concerned that this project could have a devastating effect on the Indiana bat.

Bats can be killed by wind turbines when they are struck by spinning blades or get caught in the turbines' downdraft, which causes their lungs to rupture, said Gannon.

Wind power has "great potential, but it needs to be sited properly," he said.

Gannon testified the project might have already harmed the Indiana bat when swaths of forest were clear cut to make way for turbines. Because Indiana bats roost under the bark of dead trees, clear cutting that occurred during the summer roosting season could have harmed bats, Gannon said.

He also argued the project might further harm Indiana bats once the turbines are up and running, as the turbines sit on the bats' migration route from their winter hibernation spots to their summer roosting sites.

But Beech Ridge Energy and parent company Invenergy Wind argued there is no proof of the bat's presence in the area.

The energy company conducted two mist net surveys in the area, hanging finely-meshed nets in the air to catch bats. The surveys found zero Indiana bats.

Gannon argued these mist net surveys were poorly done. Many of the mist nets were hung in open space, rather than hidden with foliage. And the surveys were conducted on bright, moonlit nights, when bats tend not to fly. "These are not sites I ever would have chosen," he said.

Gannon conducted acoustic detection surveys in the area, recording bat sounds and identifying them through a computer program. Out of 160 calls, 42 were identified, three as Indiana bats.

Although Gannon has not seen an Indiana bat at the project site, he believes there is "a high degree of scientific certainty that Indiana bats will be killed," he said.

"The habitat that is present there is almost exactly what I'd expect to find for the Indiana bat," Gannon said.

Gannon said the area is littered with the kinds of caves the bats use to hibernate in. It is also a prime foraging area and sits on the bat's migration route.

But defense attorneys argued that acoustic detection is not always accurate.

"It's not a foolproof technology," said Clifford J. Zatz. "It can produce false positives."

To date, no one has confirmed the presence of an Indiana bat on the site of the turbines.