Wind turbines: are they bird killers?

The problem

I became outraged, when I – while reading into Donald Trump’s climate policy – learned that the wind power industry each year kills around 1.4 million birds and bats (Source: The Wildlife Society Bulletin). But now, after having done some research into the issue I must ask myself; is there really a problem?

Do not get me wrong, 1.4 million birds and bats is a big number and something should definitely be done about that. But compared to the other ‘unnatural deaths’ birds have each year due to human activity, this number is actually not that significant.

Here is what I found:



Min Range

Max Range

Median/Ave. Estimated






Building Glass












Electrical lines





Communication towers






Oil Pits





Wind Turbines




(Source: USFWS)

So, as you can see above, the number one killings of birds aren’t wind turbines. It is actually our good ol’ furry friends.

Death due to collisions with wind turbines is lowest on the list with a huge estimated gap from between 140.000-500.000 bird killings each year. Note, that the above estimates from U.S. Fish &Wildlife Services only include birds, while the study from The Wildlife Society Bulletin includes both birds and bats. About 888.000 out of 1.4 million deaths in The Wildlife Society Bulletin study are bats.

If wind turbines only kill a relatively small amount of birds each year compared to other unnatural causes, then why do we focus so much energy on wind turbines? It probably has something to do with the Altamont Pass wind farm in the northern California. Hundreds of carcasses from bird raptors were found strewn across this wind farm, bird conservationists took interest and the misconception grew from there. People applied the mortality rate from the Altamont Pass to every wind farm in America, which was a huge mistake.

The Altamont Pass wind farm differs from other wind farms due to two major reasons; the location and the design. The Altamont Pass is an old wind farm and the design of the 20-year old turbines have long since been deemed inefficient. The structure of the turbine actually attracts large birds, because the frame works as an excellent perch. Collisions rates are high as a result. The blades low surface area also means that the blades needs to spin faster in order to create energy. Faster moving blades can only be considered more dangerous for birds, since it makes it hard for a bird in its vicinity to make it through without getting a close trim.

If all of that wasn’t enough, this wind farm was build in the middle of a major migratory route for larger birds. This area also houses the largest population of the endangered animal the golden eagle in the world.  Basically, this wind farm is a nightmare come true for birds.


The solution

So what do we do about it? How can we prevent these bird killings? Well, we are already doing a lot.

With new technologies with for example a slower paced blade rotation many birds will be able to survive coming into the vicinity of a windmill.

Other than that we need to look at the nesting places for birds. This study did just that and with a focus on golden eagles, they were able to find ‘sweet spots’, where relatively few birds flew by but and with the turbines still in the path of prevailing winds that can keep the turbines turning thereby create energy.

With a great focus on design and location in the future, we will be able to avoid many bird killings each year. The Altamont Pass wind farm is currently exchanging its old turbines with newer more ‘bird-friendly’ turbines.

I suggest:

Wind energy threat to birds is overblown by Huffington Post

Do wind turbines kill birds? by Julia Layton at HowStuffWorks

Wind turbines killing more than just local birds by Science Daily

The surprising way that birds and wind turbines can coexist by The Washington Post


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