Study Finds Wind Turbines Killing Bats Without Even Hitting Them

August 29th, 2008 by Timothy B. Hurst

Researchers at the University of Calgary found that the vast majority of bats found dead at a wind farm in Southwest Alberta suffered severe injuries to their respiratory systems consistent with a sudden drop in air pressure – called barotrauma.¹ The findings, published in the most recent issue of the journal Current Biology could potentially have far-reaching consequences on bat populations.

Barotrauma is a condition resulting from drastic changes in air pressure occurring, for example, when the bats fly through an area where the pressure drops dramatically, such as it does near a spinning turbine blade.

Historically, less than one bat fatality per turbine per year is considered normal, according to scientists. At this particular wind farm, the numbers were closer to 18 bats per turbine. But researchers found that the vast majority of dead bats had no visible trauma, as if they were being struck by a blade tip moving at 250 km/hr.

Upon further examination they discovered that all of the bats had suffered from severe hemmoraging of blood and died as from their lungs filling with fluid. The study shows that 90% of the bats examined after death showed signs of internal hemorrhaging consistent with barotrauma.

While it’s important to note that little is known about their population sizes, therefore, what proportion of migratory bats are being afffected by the syndrome, researchers said their deaths could have serious impacts on bat populations.

“Slow reproductive rates can limit a population’s ability to recover from crashes and thereby increase the risk of endangerment or extinction,” said biologist, Prof. Robert Barclay, of the University of Calgary.

All three species of migratory bats killed by wind turbines fly at night, eating thousands of insects—including many crop pests—per day as they go. Therefore, bat losses in Southwest Alberta could have very real effects on ecosystems as far away as Mexico and places in between.

According to co-author, PhD candidate Erin Baerwald, “Given that bats are more susceptible to barotrauma than birds, and that bat fatalities at wind turbines far outnumber bird fatalities at most sites, wildlife fatalities at wind turbines are now a bat issue, not a bird issue.”

1. Baerwald, Erin F., Genevieve H. D’Amours, Brandon J. Klug and Robert M.R. Barclay. “Barotrauma is a significant cause of bat fatalities at wind turbines.” 2008. Current Biology Volume 18, Issue 16, R695-R696.

Image: © Arturoli | Dreamstime.com

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Tags: alberta, barotrauma, bat deaths, bats, university of calgary study

About the Author

Timothy B. Hurst is the founder of ecopolitology and the executive editor at LiveOAK Media, a media network about the politics of energy and the environment, green business, cleantech, and green living. When not reading, writing, thinking or talking about environmental politics with anyone who will listen, Tim spends his time skiing in Colorado's high country, hiking with his dog, and getting dirty in his vegetable garden.

Lars Jorgensen

There is a new form of nuclear on the horizon that burns off the actinides (atoms heavier than uranium). This is the part of nuclear waste that is particularly troublesome. Once the actinides are removed (and fissioned of)the radioactivity of the waste decays in around 300 years. Look for Liquid Fluoride Thorium Reactor. This kind of reactor can even burn off the actinides from the existing reactors cleaning up our existing nuclear waste problem.
Lars Jorgensen

There is a new form of nuclear on the horizon that burns off the actinides (atoms heavier than uranium). This is the part of nuclear waste that is particularly troublesome. Once the actinides are removed (and fissioned of)the radioactivity of the waste decays in around 300 years. Look for Liquid Fluoride Thorium Reactor. This kind of reactor can even burn off the actinides from the existing reactors cleaning up our existing nuclear waste problem.
nc

Kj,nuclear waste has to be stored for thousands of years…the pyramids in giza are one of the longest standing man made buildings and they are ONLY 6000 yrs old. Nuc waste needs to be stored for 3-4 times longer than the oldest buildings in the world!!! still think its sustainable?? themostexpensive part of a nuc station is decomissioning…so dont kid yourself, Solar is the way to go.
nc

Kj,nuclear waste has to be stored for thousands of years…the pyramids in giza are one of the longest standing man made buildings and they are ONLY 6000 yrs old. Nuc waste needs to be stored for 3-4 times longer than the oldest buildings in the world!!! still think its sustainable?? themostexpensive part of a nuc station is decomissioning…so dont kid yourself, Solar is the way to go.
kj

bah, if you would bother to do some research you would find nuclear is the way to go. I am all for wind as well but it simply is not sufficient and in no way can compete with or replace coal. Nucelar power has a stigma associated with it that uneducated people just cant shake. Its clean and produces and increibly large yield. Wind power to enrich the uranium, nucelar to fuel our countries energy independence. France has been doing it for a long long time and say what you will about the French, they have an incredible wealth of scientific knowledge, particulary in physics.
kj

bah, if you would bother to do some research you would find nuclear is the way to go. I am all for wind as well but it simply is not sufficient and in no way can compete with or replace coal. Nucelar power has a stigma associated with it that uneducated people just cant shake. Its clean and produces and increibly large yield. Wind power to enrich the uranium, nucelar to fuel our countries energy independence. France has been doing it for a long long time and say what you will about the French, they have an incredible wealth of scientific knowledge, particulary in physics.
James

Wind, its cheap, renewable, and wont kill animals and environments as a coal plant, nuclear waste, and internal combustion engine would.
James

Wind, its cheap, renewable, and wont kill animals and environments as a coal plant, nuclear waste, and internal combustion engine would.
Pingback: Iberdrola Adopts Wind Industry’s First Company-Wide Avian and Bat Protection Plan : CleanTechnica
Uncle B

Knowing how windmills kill bats is interesting science. Now we need applied science and technology to prevent the bat-windmill interface. Using the scientific knowledge we have gained, can we develop a technology to ward bats away from windmills? Some Canadian Universities lack Applied Technology Colleges? How cum? are we really dumber than the Germans for example, or do we just wait for the Americans to show us how? What does China do, they are overtaking us in all ways, they must have an intelligent solution to this.
Uncle B

Knowing how windmills kill bats is interesting science. Now we need applied science and technology to prevent the bat-windmill interface. Using the scientific knowledge we have gained, can we develop a technology to ward bats away from windmills? Some Canadian Universities lack Applied Technology Colleges? How cum? are we really dumber than the Germans for example, or do we just wait for the Americans to show us how? What does China do, they are overtaking us in all ways, they must have an intelligent solution to this.
Eileen McCabe

This study has been quoted in numerous media articles and blogs. Let’s put it into perspective. It covered a small geographic area, and included the remains of only 188 bats. This is hardly a definitive study. Before we panic and abandon wind power, let’s study the effects to all wildlife over a range of areas, with larger subject smaplings.
Eileen McCabe

This study has been quoted in numerous media articles and blogs. Let’s put it into perspective. It covered a small geographic area, and included the remains of only 188 bats. This is hardly a definitive study. Before we panic and abandon wind power, let’s study the effects to all wildlife over a range of areas, with larger subject smaplings.
Just Watching

Save a bat! Eat sticks and twigs and live in a cave?
Just Watching

Save a bat! Eat sticks and twigs and live in a cave?
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