Do Wind Turbines Kill Birds?

Every time the subject of wind farms comes up, so does the question "Do wind turbines kill birds?"

Even though wind turbines provide clean energy, some environmentalists object to them on the claim that they kill an extreme number of birds, especially raptors. It’s been a real hot button issue in some areas. The situation isn’t helped any by the fact that some not-in-my-backyard folks use a concern for birds to justify their objection to wind farms.

So the question is: do wind turbines kill birds? If so, how serious a problem is it?

I hope to describe the situation and put it into some perspective on this page.

The History of Wind Farms and Bird Kill – the Altmont Pass Problem

The controversy over wind turbines as deadly for birds got its start at the first large scale wind farm in the US, the Altmont Pass wind project.

That wind farm is over 20 years old. The unfortunate fact is that this farm has caused many bird deaths. However, what many protesters fail to mention is that the Altmont Pass situation is unique and does not at all represent the effects of any installation anywhere else.

There are several problems at Altmont, beginning with its location.

The site was picked because of its wind characteristics and no attention at all was paid to the local bird population. It turns out that the wind farm was placed close of a bird sanctuary area and in the middle of a major migratory pathway.

Today, no one would build a wind farm in such a location.

The situation was made worse by the technology of the time. The turbine blades were smaller than those of current technology and had to spin at much greater speeds. Some of the towers as well as the blades themselves were lattice construction, which encouraged nesting and perching by the birds.

Today’s wind towers and blades are smooth and sleek and offer no possibility of nesting or stable perches. In addition, current blades are larger and turn at a comparatively leisurely pace.

When the problems at Altmont were first discovered, there were several breathless articles describing wind turbines as “Bird-O-Matics” or bird Cuisnarts. Alarmists applied the rate of bird kill at Altmont to all wind turbines to produce scary (but inaccurate) projections.

Do Wind Turbines Kill Birds In Perspective

So the answer to the question "Do wind turbines kill birds" is, in fact, yes birds can be killed by wind turbines, but the rate is very low.

Studies I’ve seen (such as “Effects of Wind Turbines on Birds and Bats in Northeast Wisconsin”) suggest that the average rate across to country is probably about 1 –2.5 bird fatalities per tower per year.

While a rate of zero would be ideal, that’s hardly a number that will disrupt bird populations, especially compared with other man-made sources of bird deaths.

To put it in perspective, wind turbines may be responsible for 10,000 to 40,000 bird deaths per year. Compare this to 60 – 80 million killed by collisions with automobiles and at least another 100 million killed by collisions with windows.

Communication towers and their guide wires pose another hazard. In what must be some sort of record, 20,000 in one day colliding into one tower in Kansas. Nationwide, the yearly total of birds killed by running into communication towers or their guide cables is estimated at 50 million.

Taking all causes of bird deaths from collision with man-made structures into account, the National Wind Coordinating Committee (NWCC) estimates that with regards to wind turbines “avian collision fatalities probably represent from 0.01% to 0.02% (i.e., 1 out of every 5,000 to 10,000) of the annual avian collision fatalities in the United States."

As you can see from these numbers, wind turbines and wind farms are only a minor cause of bird fatalities. The mortality will be even less with off shore wind farms because of the lower bird concentrations at sea.

It is hard not to conclude that people who argue against wind as a source of energy based on its affect on bird populations are either misinformed or using birds as an excuse rather than stating their real objection to wind farms.

Of course we’d like to have zero bird fatalities and that should be an ongoing goal. But given all the potential advantages of energy from wind and the minimal impact on birds with today’s technology, I believe we should continue to pursue harnessing the wind.


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