Science Scarce On Eagle, Wind Farm Interactions

Editor’s Note: EarthTechling is proud to repost this article courtesy of Midwest Energy News. Author credit goes to Dan Haugen.

Minnesota regulators recently rejected a wind farm developer’s plan for protecting eagles, bats and other wildlife from its turbines as inadequate.

“Inadequate” is also a good way to describe our knowledge of how wind farms actually affect eagle populations.

Minnesota wind power bald eagle goodhue

image via Shutterstock

“There’s just not a lot of good scientific studies that have looked long term at this whole interaction,” says Dr. Julia Ponder, director of the Raptor Center, a renowned large bird rehabilitation center in St. Paul.

The number of reported eagle-turbine collisions is not large, says Ponder. She’s aware of just five cases ever involving bald eagles. An average of 67 golden eagles are killed annually at a single cluster of wind farms in California’s Altamont Pass, but only around 50 golden eagles have been killed anywhere else since the industry began, she says.

To put those numbers in some context, the Raptor Center sees more than 100 eagles per year, more than any other facility of its type. Of the 122 eagles brought to its facility last year, 32 were brought in for lead poisoning (only three survived). The majority were there for some type of unknown trauma, the specific cause of which is usually impossible to pinpoint.

The types of injuries the Raptor Center sees suggest that hunting (lead poisoning), farming (pesticide poisoning), and driving (hit by cars) pose greater risks to eagles than wind turbines.

Comparing these risks is difficult, though, because there is no central database of eagle mortality causes. The Raptor Centers’ own numbers are biased because they only see birds that people find and bring in, skewing the sample towards those that are injured in cities or along roadsides.

It’s unclear whether the small number of reported eagle-turbine collisions is actually reflective of the true number, says Ponder. And it’s unknown why collisions numbers are higher for golden eagles than bald eagles, though Ponder suspects it has to do with the geographic location of existing wind farms overlapping more with golden eagle habitat than bald eagle territory.

How many eagle-turbine collisions occur might not even be the right question to ask, says Ponder. She points to a 2010 study of white-tailed eagles near a 68-turbine wind farm on the island of Smøla in western Norway, which showed the number of nesting pairs within 500 meters of the wind farm fell from 13 before construction to only five pairs a few years later.

“It appears that some of them just said, ‘OK, we don’t want to breed here anymore,’” says Ponder.

As a scientist, though, Ponder says what’s most concerning to her is that developers, policymakers and others are making decisions about the issue without the benefit of research.

“At this point I would say that the data is not being collected,” says Ponder, “and therefore the decisions are being made, as they often are, for reasons other than scientific validity.”

Midwest Energy News, launched in 2010, is a nonprofit news site dedicated to keeping stakeholders, policymakers, and citizens informed of the important changes taking place as the Midwest shifts from fossil fuels to a clean energy system.


  • Reply March 16, 2012


    This article is very misleading.  According to the Federal Wildlife Service, 440,000 birds are killed at windfarms EVERY YEAR!  Where are the environmentalists on this?  They sure spoke up about the proposed oil piplines from Canada.  They got their way when the spotted owl was threatened by the logging industry.  Why aren’t they concerned about wind farm impact?  Oh yeah, they’re all so heavily invested, financially & emotionally, they can’t oppose their crummy wind farms 

    Read more:

    • Reply March 17, 2012

      Pete Danko


      Interestingly, the the biologist who came up with the bird/wind mortality estimat of 440,000 that you cite agrees with the argument offered in this article, that there needs to be more study. When he put forward that 440,000 number he wrote: “Until a robust, scientifically rigorous cumulative impacts analysis is performed, we will not know with a high degree of certainty the true level of mortality. Admittedly, it is still relatively small.”You also suggest that environmentalists aren’t concerned about the potential impacts of wind on wildlife. I’m not sure how you arrive at this view. Environmental organizations speak up on almost every wind project proposed in the United States.The American Bird Conservancy has formally petitioned the Department of the Interior to develop regulations (instead of voluntary guidelines) protecting wildlife from wind power development. More on that here: and here: The Sierra Club, the Center for Biological Diversity and Defenders of Wildlife are fighting the proposed Jawbone project in California: 

      In Oregon, the Oregon Natural Desert Association has been engaged actively in the permitting process for wind power plants in the central part of the state, outright opposing some aspects of projects and pushing for changes to others that would reduce their impacts:

  • Reply March 21, 2012


    Given the preponderance of evidence available on the internet it is really disappointing to see such misleading information coming from Ms. Ponder.  The California Condor and Golden Eagle populations are at risk from wind turbines, the white tailed kite is extinct in some regions of the world due to wind turbines.  It’s actually quite easy to determine what will happen to these birds and it seems ridiculous to me to think that we should conduct an experiment on behalf of a sleazy developer to document the obvious.  They will die, Ms. Ponder.   It’s been proven in California, Oregon, Spain, Italy, Portugal……how much proof do you need?   Here’s one for Ms. Ponder and the other scientists interested in this issue: Spain reported 13 million migrating bird and bat deaths at wind farms last year.  How long can nature sustain the sort of damage we will see as the result of the proliferation of these giant, useless, unsustainable monstrosities and what will be the “solution” to our silent spring?  

    • Reply March 21, 2012

      Pete Danko

      Thanks for your comment, Mary. If you have a moment, could you post a link to study behind the Spain figure you report? I’m always interested in reading the latest science.

      • Reply March 21, 2012


        wsSpanish wind farms kill 6 to 18 million birds & bats a yearOn 12 January 2012, at the First Scientific Congress on Wind Energy and Wildlife Conservation in Jerez de la Frontera, Spain, the Spanish Society of Ornithology (SEO/Birdlife) made public its estimate that, yearly, Spain’s 18,000 wind turbines may be killing 6 to 18 million birds and bats.January 13, 2012 by Mark Duchamp in Canada Free PressOn 12 January 2012, at the First Scientific Congress on Wind Energy and Wildlife Conservation in Jerez de la Frontera, Spain, the Spanish Society of Ornithology (SEO/Birdlife) made public its estimate that, yearly, Spain’s 18,000 wind turbines may be killing 6 to 18 million birds and bats (1). The average per turbine comes down to 333 – 1,000 deaths annually, which is a far cry from the 2 – 4 birds claimed by the American wind industry, or the 400,000 birds a year estimated by the American Bird Conservancy for the whole United States, which has about twice as many… [continue via Web link]Web link:…

        • Reply March 25, 2012

          Pete Danko

          Thanks for your reply, Mary. I had seen that news article, but not the actual study that it relies upon — but have now found that. For those who want to check it out (noting that it is in Spanish):

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