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Wind Turbines Blamed for Bat Fatalities

A University of Colorado researcher estimates that turbines killed 600,000 bats in the U.S. last year

Wind turbines in the U.S. killed more than 600,000 bats in 2012, according to estimates made by a University of Colorado researcher.
Image Credit: National Renewable Energy Laboratory

Already under siege by a fatal disease called white nose syndrome, North American bats have another enemy: wind turbines.

A researcher affiliated with the University of Colorado estimates that more than 600,000 bats were killed by wind turbines in 2012. Writing in the journal BioScience, Mark Hayes cites earlier studies, which estimated that as many as 888,000 bats would be killed each year, before settling on his own number.

Hayes used estimates from 21 locations in the contiguous U.S. for his statistical analysis. The highest rate of bat fatalities, which Hayes describes as fatalities per megawatt per year, occurred at Buffalo Mountain, Tennessee. Some wind sites in the West recorded very low numbers.

“This estimate of bat fatalities in 2012 is probably conservative,” Hayes writes.

But Hayes says there’s still lots to learn about the problem. There’s a lack of reliable information about bat populations around the country because of their small size and nocturnal habits, he writes.

“This lack of reliable population estimates makes conservation and management planning challenging, especially in the face of other recently emerged threats to North American bat populations, such as diseases and a changing climate,” he says.

Given the ecological and economic benefits of these small mammals, Hayes recommended more research.

New hope for raptors

Government researchers have estimated that wind farms also are responsible for the deaths of dozens of bald and golden eagles. But the Associated Press reports that a combination of technology and trained spotters have helped avert fatal collisions at a large wind farm in the West.

Technicians in California are able to shut down wind turbines in Montana 1200 miles away in less than 30 seconds when the flight patterns of golden eagles and other raptors threaten a collision, the AP reported.

Tracking radar, cameras and trained spotters at the Rim Rock Wind Facility in Montana are so far proving effective in averting collisions between the birds and turbine blades. The 189-megawatt wind farm has 126 turbines, making it the states’s largest wind facility.

The wind farm’s owner says its three-tiered approach has the best chance of success in averting bird strikes.


  1. cussnu2 | | #1

    WInd turbines are killing bats birds and god knows how many bugs eaten by endangered species. They scar previously untouched lands. Yesterday it was an item on solar panels killing birds who mistake them for bodies of water or actually get their feathers burned while flying by them and fall to the ground and once again previously undisturbed land gets permanently scarred (your own site proudly showed a solar facility that consumed THREE SQUARE MILES of previously untouched land). Also yesterday, it was reported that ethanol regulations are leading to millions of previously unprofitable land being plowed up to plant corn, resultant fertilizer run off is polluting rivers and poisoning drinking water (check on Des Monies water problem with nitrates) and the fetilizer is greatly expanding the dead zone in the gulf of mexico.

    Sounds like the greenies are hell bent on saving the world if they have to destroy the world to do it.

  2. cussnu2 | | #2

    and I didn't even mention
    the danger solar is posing to fireman

  3. GBA Editor
    Martin Holladay | | #3

    Response to B.W.
    Green Building Advisor is not a "feel good" site that provides once-sided news coverage. We trust that our readers are adults, and are able to judge the context of our news stories.

    Yes, wind turbines and solar facilities have environmental impacts. But so do coal mines, and so does climate change.

    One way to reduce our environmental footprint is to use less energy. But all of us who use electricity need to find ways to produce electricity that do as little damage as possible to our planet. Wind turbines and PV arrays have less of an impact than power plants that burn fossil fuel.

    When it comes to growing corn to produce ethanol, I agree with you completely. Using corn-based ethanol as a vehicle fuel is nuts. The best thing to do with corn-based ethanol is to drink it.

  4. Brent_Eubanks | | #4

    BW - Do not mistake the ethanol mandates for any kind of green measure. They are greenwash - an agricultural subsidy disguised as environmental policy. The public may not know the difference, but I have not met even one serious student of sustainability who thinks that corn ethanol fuel is a good idea.

    If you're going to try to stir up controversy in the green community, please focus on the things which are actual controversies. Ethanol is a strawman.

  5. user-1140531 | | #5

    Birds and Bats
    This is an interesting problem because the solution seems so elusive. I am amazed that they can stop the turbines upon the approach of a flock of birds. It reminds me of that table saw that stops before it causes injury if you touch the blade.

    But this approach raises the question of how many birds approach the windmills in flocks, as opposed to the random approach of lone individuals. It also raises the question of whether or not bats fly in colony formations. But even if they do, they are mostly flying at night, so the preemptive turbine shutdown would need a detection system that does not rely on human visual spotting. What is needed to solve the bird strike problem is a wire mesh guard.

    In the copper country of Upper Michigan, there are a lot of abandoned deep, hard rock copper mines. They are mostly capped for safety, but they leave grilled openings so bats can freely have access. In the evening at dusk, at some of these mine sites, the sky is filled a massive cloud of swarming bats as far as the eye can see.

  6. Bat Removal | | #6

    Great article. Bats are very beneficial as I have come to learn working in bat removal around Columbus, Ohio. Mass killings of bats could have an irrevocable impact of the ecosystem in turn costing us humans.

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