Wyoming wind farms take a toll on eagles

Sep 17, 2013

Wyoming wind farms have killed more than 30 eagles in the last five years, according to a new study by several U.S. Fish and Wildlife Service biologists. That’s more than any state except for California -- and that’s despite Wyoming having relatively few wind turbines.

Brian Millsap is one of the study’s authors. He says it’s hard to say why Wyoming wind farms account for such a disproportionate percentage of eagle deaths. One explanation is that the state simply has more eagles than other places.

Another reason might be that Wyoming companies are more rigorous about reporting the deaths. Either way, Millsap says so far, the golden population as a whole appears to be stable.

“In spite of mortality that’s occurring at wind facilities -- and there’s a lot of other mortality occurring out there: eagles are being electrocuted, eagles are accumulating lead and dying of lead poisoning, they’re dying naturally from starvation -- all of those mortality factors, on balance, so far, seem not to have caused golden eagles to decline," Millsap says. "They’re dealing with that.”

Millsap says that’s not a guarantee though that they’ll be able to deal with it in the future, especially as more wind turbines come online. The number of turbines in Wyoming has increased dramatically since 2008, and could grow even more significantly in the next few years.

That concerns Brian Rutledge, the Vice President of Audubon Rockies. He compares the current boom in wind energy to hydropower development in the last century.

“And we’re still trying to recover from the ecological impacts of those dams," Rutledge says. "I would like us to avoid reaching those difficult points with wind energy by going about this in a much more studious and determined way -- so that we figure out the challenges before we create them.”

The Fish and Wildlife Service is working with companies on project siting, and is also developing a permitting process for existing facilities that would authorize a certain number of eagle 'takes' each year while requiring additional conservation measures.