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Golden eagle, photo by Martin Mecnarowski

‘These numbers can add up alarmingly fast’

By Sophie Osborn

As industrial-scale wind energy development has expanded in Wyoming, observers have grown increasingly concerned about potential impacts to our wildlife. Over the last few years, many Wyomingites have worked diligently to protect the iconic greater sage-grouse from this latest threat to our sagebrush landscapes.

But recently, the plight of the golden eagle has quietly captured the attention of federal and state agencies and, increasingly, concerned citizens.

Evidence is mounting that Wyoming wind farms are killing more golden eagles than expected. Measures to try to reduce eagle impacts could have a major effect on the number and location of wind turbines that are ultimately deployed in the state.

High numbers of golden eagles killed at the Altamont Pass Wind Resource Area in California in the early 1990s alerted the world to the threat that wind turbines pose for these majestic birds.

Better turbine designs and improved siting of wind farms offered hope that such fatalities could be addressed and mitigated.

But eagle fatalities at newly constructed wind farms in Wyoming suggest that such measures, while important, are not a panacea.

Wyoming has long been a stronghold for breeding golden eagles and is also an important wintering area for many eagles that originate from parts north. These long-lived birds usually don’t begin reproducing until they are about five years old and typically produce only one or two young per year.

As a result, deaths of adult eagles, which typically have low mortality rates, can have significantly adverse effects on populations.

Over the last few decades, golden eagle populations have declined across the West.

In response to these declines and the serious threat posed to these birds by wind turbines, the U.S. Fish and Wildlife Service recently developed an eagle conservation plan that provides guidance for how to reduce eagle fatalities at wind farms.

Wyoming’s wind-power build-out could pose a serious risk to eagles

According to the U.S Fish and Wildlife’s Patricia Sweanor, in a presentation given at the Raptor Research Foundation September 2010 conference (click here for the abstract), fatality rates in one geographic area in Wyoming have approached one eagle per 39 wind turbines per year.

In a nearby area, with an abundant prey base, fatality rates have been as high as one eagle per 13 turbines per year (the equivalent of approximately five eagles killed per year at one 66-turbine wind farm).

These numbers can add up alarmingly fast.

Wyoming currently has approximately 1,000 turbines operating and another thousand are planned for construction in the next few years.

The U.S. Fish and Wildlife Service estimates that the eventual build-out of wind farms in Wyoming could consist of 10,000 turbines—posing a serious risk to eagles if more stringent siting measures and best management practices are not adopted.

Golden eagles and bald eagles are protected by the Bald and Golden Eagle Protection Act and by the Migratory Bird Treaty Act. Both federal laws were developed to help protect our nation’s bird populations. The Fish and Wildlife Service is charged with implementing these federal statutes.

Killing eagles—even through unintentional activities such as harnessing the wind for energy—violates federal law, though currently no wind farm has ever been prosecuted for its actions or had to pay fines (unlike utility companies, oil and gas companies, and other energy developers that have inadvertently killed birds through their activities).

The Fish and Wildlife Service can grant permits that allow for the killing or “take” of eagles, but according to its new eagle conservation plan, companies will have to adhere to strict siting measures and conservation practices before they can procure such permits.

In addition, the agency will require that wind companies offset those eagles that they do kill by contributing to a conservation fund or by retrofitting dangerous power poles to save an equivalent number of eagles from collisions and electrocutions in the same region.

Photo by Dan Hayward

The Fish and Wildlife Service is striving to achieve a no-net-loss of eagles so it can meet its goal of sustaining stable or increasing eagle populations.

The Wyoming Outdoor Council recently submitted extensive comments on the Service’s draft Eagle Conservation Plan Guidance; click here to see these comments.

We support the agency’s plan to better protect eagles from industrial-scale wind energy development.

Last year, we included many of the advanced conservation practices that the federal government is currently proposing in our “Wind energy: doing it right in Wyoming” brochure.

However, in our recent comments to the U.S. Fish and Wildlife Service, we also suggested some additional protective measures such as conducting more frequent surveys to better document eagle use of a proposed project area prior to siting turbines, and the temporary or permanent shut-down of turbines that kill a disproportionate number of eagles.

The Council supports renewable energies such as wind energy because they could—if coupled with increased energy efficiency—help reduce toxic emissions and the use of fossil fuels.

However, we also recognize that some areas are inappropriate for industrial-scale wind development.

Where wind energy development poses little threat to wildlife and does not disrupt cultural resources and cherished viewsheds, we urge wind companies to remain in compliance with federal statutes by adopting conservation practices that will reduce adverse effects to wildlife.

Wind developers must do their utmost to live up to the “green” reputation that they often tout.

Truly green energy will exploit the Wyoming wind, but will do so while sustaining Wyoming’s wildlife and iconic vistas.

Contact: Sophie Osborn, Wyoming Outdoor Council, 307-742-6138; sophie@wyomingoutdoorcouncil.org.

Sophie Osborn is a wildlife biologist and the Wyoming Outdoor Council’s wildlife program director. She is the author of the award-winning book Condors in Canyon Country.

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