Want to save 70 million birds a year? Build more wind farms

Wind turbines are often criticised for killing birds. Fights against siting wind turbines in bird migration corridors or in bird habitat are frequent. Highly inflammatory language is used by anti-wind lobbyists such as ‘bird mincer’, ‘bird blender’ and ‘eagle killers’. Outlandish numbers of deaths are often attributed to them.

If this were true, it would be a matter for great concern and a reason to stop constructing wind farms. If humans weren’t killing birds by the hundreds of millions through habitat destruction and other human impacts that weren’t mitigated by wind farms, this would be a big problem. Even if the impact were in the same order of magnitude as other impacts, this would be a reason to slow wind farm construction.

However, replacing all fossil fuel generation with wind turbines world-wide would save roughly 70 MILLION birds’ lives annually. Wind energy is actually the form of generation with the lowest impact on wildlife. Wind farms kill less than 0.0001 per cent of birds killed by human actions annually, and perhaps 0.00000075 per cent of birds on the planet annually.

Wind farms are a strong net benefit for bird populations, and their direct impacts on bird populations are so insignificant that they can’t be considered a problem compared to the advantages.

Every other form of generation has at some point in its lifecycle the possibility of:

– Large scale, population-level mortality and/or habitat destruction causing population(s) decline and/or reduced biodiversity;

– A threat to species survival regionally;

– Biologically significant mortality or reduction in endangered or threatened species;


– Limited, but locally to regionally important mortality and/or habitat destruction, with limited population-level effects;

– Any biodiversity declines would be local to regional only;

– No threat to species survival, but demonstrated effects to physiology and/or behavior of exposed individuals;

– Incidental mortality and/or incidental habitat destruction of endangered or threatened species;

Wind energy at worst has only the possibility of:

– Limited and local mortality and/or habitat destruction, with no population- level effects;

– Biodiversity declines are unlikely;

– Endangered or threatened species may be exposed, but mortality unlikely.

This is according to the most recent of two multi-energy source studies of wildlife mortality, Comparison Of Reported Effects And Risks To Vertebrate Wildlife From Six Electricity Generation Types In The New York/New England Region, prepared for the New York State Energy Research And Development Authority in 2009.

Fossil fuel generation kills 17 time more birds per gigawatt-hour than wind energy

It is also worth considering the alternative: more fossil fuel generation. An energy governance study done in Singapore compared fatalities across forms of electrical generation in 2009 and published its results. Wind farms and nuclear power stations are responsible each for between 0.3 and 0.4 fatalities per gigawatt-hour (GWh) of electricity while fossil-fueled power stations are responsible for about 5.2 fatalities per GWh. (Coincidentally, human fatalities per TWh of electricity are roughly 0.4 for nuclear and wind, and roughly 5 for coal according to one study; the very similar ratios between human and avian mortality are striking).

This graph of estimated world-wide avian mortalities in 2006 from the energy policy report that established relative bird deaths for nuclear, wind and fossil fuel is telling:

According to Worldwide electricity production from renewable energy sources, 2011 Edition, fossil fuels generated 14,264.4TWh of electricity in 2010. Assuming this number and the ratio of mortality, replacing all fossil fuel generation with wind energy would save the lives of roughly 70 MILLION BIRDS ANNUALLY.

Human causes kill up to 1.5% of birds annually; wind farms kill 0.00000075%

Birds are killed as a result of human impacts in large numbers every year. Per Sibley Guides, the biggest human-related causes of deaths annually are:

– Lighted window impacts: 97 to 976 million

– Predatory house cats: 500 million or more

– High-tension wire impacts: up to 174 million or more

– Pesticides: 72 million and possibly many more

– Car impacts: 60 million

Even these very large numbers are relatively small compared to the threat of habitat loss from acid rain from burning coal, open-pit mining for coal, mountain-top removal mining for coal and pollution.

These numbers are still very small compared to the 100-200 billion birds on the planet. Adding all of the anthropogenic-impact causes of death above together might see 1.5 billion bird deaths, or 0.75 per cent to 1.5 per cent of the total. Unfortunate, but not species threatening except in very specific circumstances.

Wind turbines have been added to the list of bird killers in recent years. This is not because they kill significant numbers of birds; the worst cases have a handful of birds per turbine per year. According to the best impartial sources, they kill perhaps 20,000 – 33,000 birds annually in the USA. As the US has roughly 20 per cent of the wind generation capacity in the world, assuming 150,000 bird deaths world-wide isn’t unreasonable. Of course, numbers of wind turbines are increasing, but so is siting sensitivity and mitigations (more below). Compared to the roughly 1.5 billion from other sources, this cannot be considered significant. Even 10 times the the number of mortalities – which one anti-wind organisation, the American Bird Conservancy, claims – still makes wind turbines a very small contributor to avian fatalities.

It’s also worth noting that while some wind farms kill a few birds per wind turbine per year, many wind farms kill almost no birds or actually no birds per year.

“However, there has been a noticeable absence or low frequency of avian deaths at other wind farms. Kerlinger (1997) conducted a five-month survey at the Searsburg, Vermont Wind Energy Facility and found no fatalities. Lubbers (1988) surveyed eighteen 300kW wind turbines in Oosterbierum, Denmark, and found only 3 fatalities over 75 days, or less than 0.8 per turbine per year. Marsh (2007) found a bird casualty rate of 0.22 birds per turbine year after monitoring 964 turbines across 26 wind farms in Northern Spain. Rigorous observation of a 22-turbine wind farm in Wales documented that it has killed no birds, and researchers found a shift in bird activity to a neighboring area (Lowther, 1998).”

Wind turbines have tended to kill larger birds such as raptors and vultures in slightly higher numbers. This is important as there are generally fewer of the larger birds and in the case of raptors they are an apex predator. Threatening populations of these birds has been a concern, especially in the Altamont Pass, which is a raptor migration route. However, bird deaths per turbine have dropped off their in recent years with the elimination of older, lattice-tower turbines that were used as roosts by raptors. Attention to siting in larger bird migration routes is reasonable, as is attention to habitant for species in threat of extinction.

And a recent UK study on 10 bird species near wind turbines found that construction disrupted populations slightly, but that operation did not cause any challenges for the majority of species, aided one species and only had a minor negative impact on numbers of one type of bird. In general, song birds migrate at 2000-4000 feet, well above the level of wind turbines. Sea birds have been shown to avoid wind turbines based on radar and thermal imaging studies; the study found that millions of sea birds migrated past an offshore wind farm annually, and only two were killed.

The wind industry continues to reduce its impact on birds

Despite the comparative benefits wind farms and the low impacts, the wind industry and researchers continue to research ways to reduce impacts on wildlife further. Promising approaching outside of siting sensitivity include radar assessment of bird density causing wind farm feathering, painting the blades purple to avoid attracting birds during the day and avoiding steady white lights that attract insects and birds at night.

Mike Barnard has been a deeply interested observer of energy systems for three decades. Following a lengthy discussion with Margaret Atwood and others related to siting of wind turbines in a major birding area on her blog, he became a blogger on energy concerns, focusing on debunking myths about wind energy. As a day job, Mike has had the good fortune to work on Smart Grid projects for IBM’s clients, in addition to many other interesting initiatives that IBM is uniquely positioned to undertake.  More of Mike’s material on wind energy can be found at http://www.quora.com/Mike-Barnard/answers/Wind-Power. He tweets only the most interesting things he runs across at @mbarnardca.


16 responses to “Want to save 70 million birds a year? Build more wind farms”

  1. George Papadopoulos Avatar
    George Papadopoulos

    I hope this article might put a bit of balance in the picture:http://www.bbc.co.uk/news/science-environment-19208400

    Whilst wind farms DO lots of kill birds and bats, they also create a lot of habitat disruption. One large dirty grubby coal plant makes 1 gigawatt of electricity.

    The equivalent in wind is about 3000 wind turbines, assuming 30% capacity, which will cover most of the NSW Great Dividing Range.

    1. Ketan Joshi Avatar
      Ketan Joshi


      Mike’s article states a value in fatalities per GWh, making your comparison using either installed capacity or capacity factor irrelevant.

      Additionally, it might be worthwhile reading articles, prior to including them, lest they counter the disjointed statement you are trying to make.

      “Because geese have relatively limited manoeuvrability in flight and often migrate at night, the threat of colliding with wind turbines was perceived to be substantial.

      The new research, however, has countered this assumption.”
      – From the article.

      1. George Papadopoulos Avatar
        George Papadopoulos


        The point I am trying to make is that bird fatality statistics is only part of the story.

        Habitat disruption/destruction is the other.

        Wind turbines will not kill birds if birds are terrorised into abandoning their habitat/normal flight paths.

    2. wideEyedPupil Avatar

      3000 turbines for 1GW capacity? care to show your workings so we can try and find at least one mark out of ten for you there?

      1. George Papadopoulos Avatar
        George Papadopoulos

        3000 1MW wind turbines x 30% capacity = 1GW
        or to be a little fairer 3000 2MW wind turbines x 30% capacity = 2GW – or the output of only ONE coal station. What a waste of resources wind turbines can be!

  2. George Papadopoulos Avatar
    George Papadopoulos

    Build more wind turbines to save birds? True perhaps if the wind blew at 30km/h 100% of the time, but no coal plant has been successfully shut down yet as a consequence of wind energy.

    1. Ton Hirdes Avatar
      Ton Hirdes

      Wind energy can deliver up to 50% of electricity demand. Together with other renewables this can become 100%. So there is still a lott wind energy to be build (and save birds). Yes, there is not enough wind energy right now. And yes, the renewables mostly only take over the growth of electricity demand. But it is not an argument that no coal plant had been shut down because of wind. That’s mainly because people keep using arguments against wind or other renewables. Your argument will become selffulling.

      1. George Papadopoulos Avatar
        George Papadopoulos

        Well, wind energy can deliver 100% of electricity of demand, if they were to be backed up by huge and endless battery storage facilities, and they were to fill all of Australia with them, including on high rise buildings and even more out at sea.

        Is this a renewable energy solution? I think it is more of a ugly, unhealthy, noisy problem.

        1. health advocate Avatar
          health advocate

          George, you may be interested in this briefing paper on the health benefits on acting on climate change: http://www.climateinstitute.org.au/verve/_resources/OurUncashedDividend_CAHAandTCI_August2012.pdf

          Apparently air pollution kills more people than the road toll each year. I know, I was surprised too!

          Renewable energy seems far from unhealthy in this context.

          1. George Papadopoulos Avatar
            George Papadopoulos

            Well “Health Advocate”,

            Let’s discuss something more relevant like: http://dea.org.au/images/uploads/submissions/SA_Wind_Farm_Developments_Inquiry_and_Health_Submission_07-12.pdf

            In this harm-benefit analysis document, it states that “The main component of wind turbine exposure that may have adverse effects for up to about 10 per cent of people nearby is audible noise”” Mind you this is a little at odds with the 2007 paper of Pederson, but even more so with the unpublished research on the noise nuisance at the SA Waterloo site.

            Why not install MASSIVE wind turbines in urban areas like Sydney University, just outside Professor Chapman’s office.

            It might help put the argument over air vs noise pollution into context.

          2. Ketan Joshi Avatar
            Ketan Joshi


            In reply to your comment below, you’ve unashamedly taken your quote out of context, and intentionally excluded the sentences directly after your selection.

            “This situation is comparable to
            other noise sources in society such as roads, aircraft, neighbouring air conditioning, in its effects on people. There is no support in the literature that other sonic aspects of wind turbines such as infrasound at the sound pressure levels that are emitted from modern wind turbines cause adverse health effects. We are surrounded by many sources of infrasound, such as from our own body heart beat for example, which do not cause any recognised health problems.”

            As above, it pays to ensure the link you are posting does not swiftly demolish the very point you are attempting to make.

          3. George Papadopoulos Avatar
            George Papadopoulos

            Ketan the shame falls on the DEA and others for thinking it is OK to expose whole swathes of rural Australia to a unique whoosh whoosh sound that is “comparable” to other sources of noise that are well known to annoy people – all for the sake of a handful of jobs in that region. Pedersen et al have identified wind turbine noise as the second most annoying source of industrial noise.

            Compare this logic to air pollution: is it OK to harm the health of many for the sake of hundreds of jobs in mining, smelting, coal energy or whatever other industry? If you apply the DEA logic to air pollution, then yes it is OK: the economic “beast” must thrive and prosper in order to provide heaps of jobs and whatever else. It must be OK, in the mind of the DEA, to poison people’s lungs for the sake of preventing suicides and mental depression associated with unemployment?

            Whilst many question the real costs of fossil fuels: are we ever going to get focussed on the real cost of renewables? Solar panels might just end up being the cheapest option by far.

  3. 1barbaradurkin Avatar

    Given that wind can only be considered efficient in context of shifting public wealth to multinationals, providing opportunity for those laundering money, or those seeking tax sheltering, and efficient for killing of large numbers of birds and bats while destroying their habitat, and constituting a take of marine mammals, we’re better off economically, environmentally and socially without it.

  4. Venture Guy Avatar
    Venture Guy

    Really? Seriously just reprinting falsehoods and wild guesses doesn’t make it true. A study of radio tracked Golden Eagles in California documented that the number 1 killer of was in fact Wind Turbines and all their extra wires and power equipment. The state of Pennsylvania documents 25 bats per turbine per year. And your “piece” is just summarized guessing. The study purporting that building, cars, cat, etc was just a bunch of wil guesses from people trying to make a point with little to no study. This is a shameful example of trying to make your wrong appear palatable!

  5. CaptD Avatar

    Seems the Pro Bigs (Coal, Nuclear and Gas) are doing everything they can to make Solar (of all flavors) look bad, but little by little people are starting to realize that they no longer have to live as Energy Slaves since once they pay off their Solar (of all flavors) they will be able to generate their own FREE Energy…

    Welcome to the 21st Century where Solar allows Energy Freedom!

  6. HarryDutch Avatar

    What a crap, none of these numbers hold a candle to cats, which are estimated to kill 1.4 to 3.7 billion birds every year…

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