Collisions with rotating wind turbine blades kill a variety of birds in Wyoming — from passerines to raptors. Exactly how many birds — and whether mortality rates might pose a threat to local and migrating bird populations — remains unknown, according to state and federal wildlife officials.

The overlap of strong, steady winds and prime wildlife habitat — such as for the greater sage grouse — also poses threats, unless wind energy facilities are located to avoid impacts to critical wintering, breeding and nesting areas. Designing wind facilities with these considerations requires the collection of wildlife and habitat data long before roads are carved, concrete pads are poured and wind turbines erected.

That’s the message of a former federal wildlife biologist who is sounding the alarm in an effort to encourage less harmful development as Wyoming’s wind energy is anticipated to boom.

“Most of the [Wyoming wind energy] development is just going off like a rocket right now, and we already have eagles that are getting killed by wind turbines — a hell of a lot more than people really understand.”

Mike Lockhart, wildlife biologist

Despite regulations and voluntary efforts to minimize wildlife impacts, Mike Lockhart and other biologists say wildlife officials must do better to collect more comprehensive data and apply more scrutiny to the industry.

“Most of the [Wyoming wind energy] development is just going off like a rocket right now, and we already have eagles that are getting killed by wind turbines — a hell of a lot more than people really understand,” Lockhart, a former U.S. Fish and Wildlife Service biologist, said.

Lockhart, who now works as a consultant for private companies, surveys eagle populations in Wyoming — mostly around Medicine Bow and in the Shirley Basin. The region is the “heart and soul” of golden eagle habitat in North America, he claims. Experimental wind turbines here date back to the 1980s, and it’s the epicenter of existing and prospective development ambitions.

Wind turbines near Hanna catch the light at sunset in November 2017. (Andrew Graham/WyoFile)

Two key electrical transmission projects that will tie central Wyoming wind to several western states are expected to double the state’s wind energy capacity to 6,000 megawatts by 2030, according to those close to the industry.

While some wind energy representatives say tools exist to reap energy from the wind while conserving species, Lockhart contends that level of development will require much more planning to consider cumulative impacts to eagles, raptors, songbirds and all other wildlife. Additionally, the FWS should reconsider its “incidental take” allowance for individual wind energy facilities, he said.

“The Fish and Wildlife Service has provided an allowable take for those [individual] projects of 10 to 14 eagles per year,” Lockhart said. “You multiply that out by the 30-year project life — that’s a hell of a lot of eagles, and they can’t sustain that kind of impact.”

Existing avian impacts

In a landmark case, Duke Energy Corp. was fined $1 million for killing 14 eagles and 149 other birds at four wind farms in Wyoming from 2009 to 2013. The company “failed to make all reasonable efforts to build the projects in a way that would avoid the risk of avian deaths by collision with turbine blades, despite prior warnings about this issue from the U.S. Fish and Wildlife Service,” according to the U.S. Department of Justice.

ESI Energy Inc., and its affiliate NextEra Energy, were fined $8 million in April for killing more than 150 eagles in several states over a 10-year period, including at wind facilities in Carbon and Laramie counties.

A bald eagle soars at the Seedskadee National Wildlife Refuge. (Tom Koerner/USFWS/Flickr)

In both cases, the companies failed to acquire federal “incidental take” permits, which can protect operators from running afoul of the Migratory Bird Treaty Act. But Lockhart questions the justification of allowable incidental take numbers, as well as the FWS’s current level of accounting and analysis for the potential cumulative impact to bird populations from multiple, individually permitted wind farms within a region.

“All of them [wind facilities] are impacting eagles, without a doubt,” Lockhart said. “But the extent of those impacts probably varies wildly, and I just don’t know what it is. And I’m not sure anybody does.”

An estimated 538,000 birds are killed by land-based wind turbines each year in the U.S., according to an article by the American Bird Conservancy analyzing data from the U.S. Wind Turbine Database. A FWS estimate suggests an average 234,012 bird kills annually, as of 2017. The FWS was unable to respond to WyoFile’s inquiries in time for this story.

There’s no research that indicates wind turbine blade strikes threaten any bird species at a population level, according to Wyoming Game and Fish Department Deputy Director Angi Bruce. However, the agency, which analyzes potential avian impacts, is concerned that might already be the case, “especially when you look at locations that have multiple wind farms,” she said. “Understanding the cumulative effects is still ongoing and not conclusive at this time.”

Mitigation efforts

For all of the advantages of wind energy — a free fuel supply, low carbon footprint and freedom from volatile international commodity markets — wind energy does come with inherent downsides such as spoiled viewsheds. Devastating avian mortality, and other wildlife impacts, don’t have to be part of the equation, Power Company of Wyoming Communications Director Kara Choquette said.

“The tools are there and available, and partnerships are possible with the Fish and Wildlife Service to achieve conservation goals — and that’s something we chose to do,” Choquette said.

A bald eagle is released from a lift during research at the National Wind Technology Center in Colorado in 2016. (Dennis Schroeder/National Renewable Energy Laboratory/Flickr)

Power Company of Wyoming’s Sierra Madre and Chokecherry Wind Energy Project in Carbon County has been completely reconfigured since its inception more than a decade ago, based on continuous wildlife surveys as well as advancing technology. Rather than 1,000 wind turbines, the project will include 600 turbines, thanks to larger and more efficient wind turbine designs, for example. Turbines will be placed away from ridgelines based on continuous bird flight surveys, Choquette said, and ongoing observations via towers and cameras will help inform adaptive management practices, such as shutting down wind turbines when birds are active in the area.

“It’s literally going through and screening all of the datasets and really trying to find the best place and working to avoid and minimize potential impacts on avian species,” Choquette said. “It’s a big part of our job.”

PacifiCorp owns and operates the largest number of wind facilities in the state, and it plans to continue expanding its wind energy capacity here. The utility collects “several years” of wildlife data to inform where it locates wind turbines and how to mitigate impacts during operations.

“These surveys typically include habitat and usage surveys for avian, bat, and various wildlife species, including elk/ antelope (crucial winter range), prairie dogs, swift fox, greater sage grouse, and other protected species,” PacifiCorp states in a fact sheet.

Wind turbines face gusts from the southwest at a facility north of Medicine Bow in August 2019. (Dustin Bleizeffer/WyoFile)

Efforts include “buffer zones” to distance facilities from nests and holding off on construction activities during certain times of the year. Both PacifiCorp and Power Company of Wyoming are retrofitting power poles to discourage nesting and perching.

“Our objective is no [wildlife] mortalities,” PacifiCorp spokesperson David Eskelsen said. “If any do occur for protected species, they are reported to [the FWS] within 24 hours.”

For all the federal and state regulations and oversight, local officials still don’t have a full understanding of the industry’s impact on raptors and other wildlife, according to Carbon County Commissioner Sue Jones.

“To be quite honest, we don’t hear a lot and there’s no way to tell, as far as I know,” Jones said. Many areas of Carbon County, particularly around Medicine Bow, have become “industrialized” with wind energy, she said. As with any energy development, planning and proper siting is vital to balance natural resources. “There’s a tipping point, and we have lost things that are not replaceable, like viewsheds, literally.”

Dustin Bleizeffer is a Report for America Corps member covering energy and climate at WyoFile. He has worked as a coal miner, an oilfield mechanic, and for 25 years as a statewide reporter and editor primarily...

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  1. Some good arguments here, but when it comes to the ‘carbon footprint’, the energy it takes to construct and erect these behemoth eyesores far outweighs the savings with the short lifespan. And there are much better, more efficient designs out there!
    Bottom line, no matter what and how some feel about these bird killers, the BILLIONS of taxpayer dollars in subsidies spent on them, there are NO true savings…

  2. This is disgusting! They kill wildlife and destroy God’s beautiful landscape use fossil fuels that’s why he put them here!

  3. The Green Energy fools never thought this wind turbine/solar issue thru. Just like the biofuel. Which releases HUGE VOLUMES of CO2 into atmosphere!! So let’s do this. Line up stationary bicycles. Hooked to generators. Each Green Freak/left liberal retard can simply peddle away. 16 hours a day to provide electricity for rest of us. Mean time shut down biofuel plants and go back to REAL GAS/Diesel.

  4. Not only do the windmills chop up birds, there is the problem of disposing of the non degradable blades. They are buried in landfills and remain intact for apparently forever or at least until someone figures out another way to get rid of them. Since some are already being disposed of that way, apparently they do not have a very long useful life.

    1. 10 years is aprox life of turbine blade. They are wood frame. Huge waste. Just as these biofuel plants puke out many tons of CO2 every year. More then cars using real gas. Biofuels is joke.

  5. Where are the cries of outrage from all the so called “environmental” NGOs over the bird and bat slaughter?? What? doesn’t matter how bad the impacts are if they are for “green” energy? Or maybe the reporter didn’t feel it necessary to obtain comments from the Center for Biodiversity? Greenpeace? Earth Justice? World Wildlife Foundation? Sierra Club? EDF? Any of the dozens and dozens of other well funded activist NGOs? All of whom enjoy tax-free status while inflicting enormous costs on the rest of us. How many of them would chime in if it were a mine killing a couple eagles a decade? The hypocrisy is disgustingly blatant.

  6. I just read an article by Kevin Hinton: 12 Environmental Effects of Coal Mining. After reading this article I have no doubt that if eagles could read -they would choose wind power over coal power for their own health and their home !! I’m sorry and concerned about the impact of wind power on wildlife….but what are the options ? What has been the environmental effects and impact for many years of coal mining ? Climate change…methane gas, loss of ozone layer, global warming, the release of radioactive materials, acid rain, heavy metal contamination such as lead, mercury and arsenic…! Air pollution and it’s effects -lung cancer, TB, heart failure. Changing PH in streams and lakes….loss of habitat for not only Eagles but all life….
    For me- growing up in Sheridan Wyoming in the 50’s -70- the big plus about coal mining was that it produced good paying jobs for the community but also some large pits that filled with spring water. This new water habitat was welcome on the dry prairie and was a place to swim, fish and boat. The mines also changed the culture of people around Sheridan. The mines attracted people from Poland for example and this added something to the culture of the Sheridan area including music and faith.
    Wyoming is missing a solution to the energy problem :.develop geothermal energy ! You are sitting on top of a Supervolcano- a Caldera ! Iceland is way ahead ! They are producing electricity now . Check out :

  7. A recent study in Norway found painting one turbine blade black reduced bird mortality by 72 percent. I find it hard to believe governmental agencies and the wind turbine industry have not found this study in their research. Perhaps painting a second turbine blade another color, to be determined by research, may further reduce bird kills. Attaching a high frequency whistling device to turbine blades may alert bats and birds to the danger.
    The report:,four%20turbines%20beginning%20in%202013.

    The Study:

  8. Green energy isn’t so green when you look at the underbelly. All energy sources have an impact on the environment which is often ignored by those pushing the narrative to eradicate coal and other fossil fuels. Mr. Vanderhoff’s comment is a case in point – this article does not support the narrative, thus the author must be biased. No, its not bias but actual facts that the so called green energy narrative is not as green as the promoters want you to think. Do not get me wrong, I think wind and solar play a part of the energy structure of this country and support them, but let’s not fool ourselves into thinking it is 100% clean energy with no impact on the environment.

  9. When it comes to man-caused mortalities of large raptors, before we shut down wind turbines could we maybe get rid of lead-based ammo and leaded fishing tackle first ?

    P.S. this biologist seems like he might have a bit of a bias and be building to a conclusion…

    1. I don’t believe that story about lead from ammo killing rapture. Digestive system won’t break down lead. Try it. Take BB/2/4/6/8 shot. Weigh it. Swallow it. Passes on through system in 24 hours or less. Catch it. Wash it off dry it. Weigh it. No loss. Just like the myth kids chewing on window sills and getting lead in system. Don’t happen. It is non leachable folks. Doesn’t happen in raptures either. Passes on through digestive system

      1. I’m a bit disappointed WyoFile. Years ago you fact checked some trivial data point I submitted and yet you let something like this comment come thru? Actually this is wrong. There are numerous studies out there where it has been proven there is lead uptake in raptors and other animals that feed off discarded carcasses that have been shot with lead ammunition. I know you do not like links, but here is the link to a recent study on the issue.

      2. Ingesting lead paint chips absolutely causes damage. The confidence in your false statements is not surprising.