AUGUSTA (AP) – A wind power development proposed atop Mars Hill Mountain in central Aroostook County was granted conditional approval to proceed, despite an appeal from environmentalists worried about its impact.

The Board of Environmental Protection on Thursday denied a Maine Audubon Society appeal, deciding instead to allow the project if the effects on wildlife such as birds and bats who migrate through the area were monitored.

“It’s important as a record of what we expect wind power projects to do,” said board member Irving Faunce.

The state Department of Environmental Protection approved the installation of 33 turbines along the mountain’s ridge of 33 last June.

But Maine Audubon filed an appeal of the company’s permit, arguing that a year of formal study would be needed to gather data about bird and bat migrations before the 400-foot-tall turbines could be deemed safe for wildlife.

The Maine Department of Inland Fisheries and Wildlife raised similar concerns but decide after meeting with Evergreen Windpower LLC this summer to allow the turbines as long as the company monitored the surrounding environment.

The board voted to deny Maine Audubon’s appeal, saying formal pre-construction studies that it wanted could make it more difficult for the company to finance the development, which board members agreed would benefit Maine.

Evergreen officials said the project is on schedule to have financing as soon as federal legislators renew an energy tax credit, which could come up for a vote this fall. Construction could then begin as early as next spring.

After some debate, the board added the requirement that Evergreen inform the state environmental department upon receiving financing for the wind farm, and that pre-operational wildlife surveys must begin within 30 days of that.

Board Chairman Richard Wardwell of Orono said the company could be trusted to take precautions if the pre-operation research reveals anything unexpected.

“Whacking a bunch of birds with those blades, it just doesn’t make sense as a businessperson to do that,” he said.