SWANTON, Md. - A state Department of Natural Resources biologist is casting doubt on a claim that substantial numbers of federally endangered bats are threatened by a Constellation Energy wind farm in western Maryland.

Opponents are suing to block the start-up of what would be Maryland's first industrial wind-power project.

They claim in a federal lawsuit that a "robust population" of Indiana bats hibernates in a cave about 13 miles from the 28-turbine project.

But biologist Dan Feller told the Cumberland Times-News Monday there has been no substantiated record of Indiana bats in that cave or in another, about 10 miles away, for a long time.

He says most of the hibernating bats are believed to be little brown bats.

A subsidiary of Constellation Energy Group Inc. has signed an agreement to convert a 21-acre brownfield in West Deptford into a 5-megawatt solar farm.