Navigant Research Blog

Wind Power is Killing Birds and Bats – So What?

Jenny Gerson — August 2, 2013

That wind farms kill birds and bats is not news.  Nevertheless, a recent study by S.K. Smallwood, has gained attention recently for finding that estimates of mortality rates may be understated.  Smallwood’s conclusions have been overstated in the press – cited as another reason to mistrust renewable energy.  In the wind industry and in wildlife protection circles – among the experts, in other words – the findings are less alarming.  Two reasons stand out: a) the number of birds killed by wind power generation is minimal compared to other sources of human-caused bird kills, and b) the wind industry continues to collaborate with wildlife agencies to create solutions that will further minimize windmills’ affects on wildlife.

To put things into perspective, Smallwood’s estimate of 573,000 bird kills at wind farms (based on 2012 wind energy levels) pales in comparison to other human-caused bird deaths. In 2002, the U.S. Fish and Wildlife Service estimated the following numbers of annual bird deaths from human causes:

  • Hundreds of millions of deaths (estimates vary widely) from collisions with buildings
  • 4 to 50 million deaths from collisions with communication towers
  • 174 million deaths from collisions with  transmission lines
  • 60 million deaths from collisions with cars
  • 72 million deaths from pesticide poisoning
  • Up to 2 million deaths from oil and wastewater pits
  • 39 million deaths due to cat predations

These figures are now outdated, and have likely increased, further dwarfing bird kills at wind farms.  Additionally, wind power generation poses much less risk to birds than other forms of energy generation.  It’s estimated that, in 2006, fossil-fuel power plants were responsible for 14.5 million bird deaths.

Night Off

Because wind power is a safer alternative for wildlife compared to other sources of energy, wildlife agencies and protection groups have been working with the wind industry for years to minimize impacts to all wildlife at wind farms while promoting wind energy development.  These efforts resulted in the 2012 U.S. Fish and Wildlife Service Land-Based Wind Energy Guidelines, which describes best practices for siting and surveying wind farms.  What’s more, wind developers are encouraged to take preemptive actions to avoid harming wildlife, such as siting farms as per the USFWS Guidelines, purchasing incidental take permits if there is an unavoidable risk of harming protected wildlife, and other mitigation strategies for potential impacts.  Even when all of these have been considered, deaths still occur, and some wind developers are taking matters into their own hands to minimize bird and bat kills.  Since finding a dead endangered Indiana bat at the company’s wind farm in 2011, Duke Energy pauses operation of the wind farm from dusk to dawn during the bat’s migration season to avoid future fatalities.  Other wind developers are now curtailing operations at wind farms when bird or bat migration is occurring.

Wind farms, however, are not excluded from wildlife laws, contrary to the thoughts of some. If wind developers choose to move forward without taking the above-mentioned precautions and the death of a protected species occurs, an investigation and lawsuit are possible.  This has occurred over the deaths of bald and golden eagles and Indiana bats on numerous occasions.

Birds and bats are being killed at wind farms, but not nearly to the same extent of other anthropogenic causes.  All forms of power generation are dangerous for wildlife.  Wind power is just less so.

2 Responses to “Wind Power is Killing Birds and Bats – So What?”

  1. Simon says:

    Having worked my whole life in the renewable energy industry, I have long believed that wind farm related bird and bat deaths, while bad, had to be no worse and possibly much better than other energy generation methods. It is good to see my “gut” feeling proven to be correct.

    Having a partner involved in wildlife conservation, and living rurally, the far greater threat are cats. A recent peer reviewed study puts the number of deaths due to feral cats as 7 million PER NIGHT (birds and small mammals, Aus wide). On a current affairs show the other night they interviewed a lady who is anti-wind farm. Her two arguments were loss of a pretty view and bird deaths.

    She had several cats.

    While the wind industry is spending cash and time trying to find solutions, the feral cat population grows at an estimated 10% per annum.

    So very good to see a bit of a reality check in articles like this.

  2. douglas prince says:

    Using VAWTs eliminates the whole “can’t see it” conundrum with birds and bats.

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