Hibernating Indiana Bats. Photo credit: U.S. Fish & Wildlife Service & Ann Froschauer / CC BY 2.0
A Maryland wind farm could be the first in the Northeast to receive an approved habitat conservation plan. The U.S. Fish & Wildlife Service just released a draft plan, open for comment, for the 70 megawatt facility near Oakland. Conservation concerns include potential danger to the endangered Indiana bat.
Run by Criterion Power Partners, the project was Maryland’s first operating wind farm. Twenty-eight turbines generate green energy, but they’re also a significant hazard for birds and bats flying through the area.
Both bats and birds can die after colliding with turbine blades, but collisions are only part of the danger for bats. Barotrauma—when sudden drops in air pressure around moving turbine blades cause internal hemorrhaging—is also deadly.
A species of particular concern is the endangered Indiana bat, a quarter-ounce bat with mouse-like ears. Indiana bats live in the eastern United States, but during the winter they hibernate in only a few caves, many in Indiana. Placed on the Endangered Species list in 1967, they experienced rapid population decline due to disturbance of hibernation sites, pesticide use, and loss of forest habitat. White-nose syndrome now poses an additional threat to bat populations, including Indiana bats.
Under the Endangered Species Act it is illegal to kill or “take” endangered and threatened wildlife. Wind farms cause unintentional death of birds and bats, but they can do so legally with an incidental take permit. The permit makes allowances for a certain number of deaths as long as the wind farm takes steps to protect the species on site and elsewhere. The draft conservation plan for Criterion Wind allows for 14 Indiana bat deaths over 21 years of operation.
To help protect bats, Criterion plans to turn the turbine blades parallel to air flow when wind speeds are low and when bats are most likely to fly, between sunset and sunrise in late summer and early fall. They estimate that this change will save an estimated 50 percent of bats without losing significant power. Criterion will also take steps to help cave-dwelling bats elsewhere by building cave gates in eastern Tennessee, Pennsylvania, Virginia and West Virginia.
The FWS will accept written comments on the draft environmental assessment, Criterion’s permit application, and the draft habitat conservation plan through September 28, 2012.
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Video: Bird Collides with Wind Turbine Blade