A federal judge in California has ruled in favor of American Bird Conservancy in a lawsuit over a federal rule that would have allowed wind energy and some other companies to harm or kill Bald and Golden Eagles for up to 30 years.

Eagles are at risk of colliding with the fast-spinning blades of wind turbines. More than 2,000 Golden Eagles have perished at one facility alone: the Altamont Wind Energy Project in California. Like most birds in the United States, however, eagles are protected under federal law. Incidental “take” permits exempt companies from prosecution if the birds are harmed.

In a 46-page decision issued Tuesday by U.S. District Judge Lucy H. Koh of the Northern District of California in San Jose, the court ruled that the U.S. Fish and Wildlife Service (FWS) and the U.S. Department of the Interior violated the National Environmental Policy Act by expanding the maximum duration for “programmatic” eagle take permits sixfold without first assessing the impact those rules would have on eagles, which often collide with fast-spinning wind turbines.

In a major victory for Bald and Golden Eagles, the court granted ABC's request to set aside the 30-year rule, handing it back to FWS for further consideration.

Bald Eagle, FloridaStock/Shutterstock

“We are pleased that the courts agreed with us that improper shortcuts were taken in the development of this rule,” said Dr. Michael Hutchins, Director of ABC's Bird Smart Wind Energy Program. “The court found that important laws meant to protect our nation's wildlife were not properly followed by the U.S. Fish and Wildlife Service, putting Bald and Golden Eagles at greater risk.”

A previous rule for eagle-take permits, in place since 2009, had limited their duration to five years. But in 2012, with wind energy on the rise, FWS proposed a new rule that would increase the duration to 30 years.

Altamont Pass wind facility, Terrance Emerson/Shutterstock

The National Environmental Policy Act ensures that federal agencies take a hard look at the environmental consequences of their actions. The federal law requires agencies — in this case, FWS — to prepare a detailed environmental impact statement, or a less-rigorous environmental assessment, for new or revised rules, regulations, or other policies.

In the case of the 30-year rule, FWS did neither, claiming that the new rule was merely administrative in nature, the court said.

As a result, ABC and fellow plaintiffs Debra Shearwater, Stephen A. Thal, Dr. Carolyn Crockett, Michael Dee, and Robert M. Ferris sued the federal agencies in June 2014, a few months after the new rule took effect. In their lawsuit, the plaintiffs contended that the Department of the Interior did not offer a strong legal or scientific justification for increasing the duration of the permits.

Immature Bald Eagle, Menno Schaefer/Shutterstock

The U.S. Fish and Wildlife Service is one of ABC's most important partners, said ABC President George Fenwick.

“We collaborate frequently, share many goals, and have enjoyed many successes together," Fenwick said. "However, FWS is encountering unprecedented financial constraints that lead to shortcuts and poor decisions. We hope that this court decision shines a light on the need for the Service to be fully empowered to do the job it is mandated to do. Our nation's wildlife — and the agency appointed to protect it — deserve nothing less.”

Libby Sander is Senior Writer and Editor at American Bird Conservancy. As a journalist, she has written news stories and award-winning features for The New York Times, the Washington Post, and The Chronicle of Higher Education.