A new study shows that in spite of updated designs, U.S. wind turbines are killing hundreds of thousands of birds annually—a number that may balloon to about 1.4 million per year by 2030, when the ongoing industry expansion being encouraged by the federal government is expected to be fully implemented.
The findings were issued in a new study by scientists at the Smithsonian Institution Migratory Bird Center (SMBC), the U.S. Fish and Wildlife Service (FWS) and Oklahoma State University (OSU), published in the December issue of the journal Biological Conservation and authored by Scott Loss (OSU), Tom Will (FWS), and Peter Marra (SMBC).
The study, “Estimates of bird collision mortality at wind facilities in the contiguous United States,” was based on a review of 68 studies that met rigorous inclusion criteria and data derived from 58 bird mortality estimates contained in those studies. The studies represented both peer-reviewed and unpublished industry reports and extracted data to systematically estimate bird collision mortality and mortality correlates.
“The life expectancy for eagles and all raptors just took a big hit. Clearly, when you look at this study and you consider the new 30-year eagle take permits just announced by the Department of Interior, this is a bad month for this country’s iconic birds,” said Dr. Michael Hutchins, National Coordinator of American Bird Conservancy’s (ABC) Bird Smart Wind Energy campaign.
According to George Fenwick, President of ABC: “This study by top scientists says that hundreds of thousands of birds are being killed by the wind industry now, and that the number will escalate dramatically if we continue to do what we have been doing. The biggest impediment to reducing those impacts continues to be wind industry siting and operating guidelines that are only followed on a voluntary basis. No other energy industry gets to pick and choose where they put their facilities and decide how they are going to operate in a manner unconstrained by federal regulation.”
“The industry has been saying for some time that bird mortality would be reduced with the new turbines compared to the older, lattice structures. According to this study, that does not appear to be the case,” Hutchins pointed out, since the study excluded data from wind developments using older designs.
“The status quo is legally, as well as environmentally, unsustainable,” Hutchins said further. “The federal government is seeking to promote an energy sector in a manner that is in violation of one of the premier federal wildlife protection statutes. In December 2011, we formally petitioned the Department of the Interior to develop mandatory regulations that will safeguard wildlife and reward responsible wind energy development. We continue to believe that is the solution.”
A coalition of more than 60 groups has called for mandatory standards and bird-smart principles in the siting and operation of wind energy installations. The coalition represents a broad cross-section of respected national and local groups. In addition, 20,000 scientists, ornithologists, conservationists, and other concerned citizens have shown their support for mandatory standards for the wind industry.
According to ABC, poorly sited and operated wind projects pose a serious threat to birds, especially birds of prey such as Bald Eagles, Golden Eagles, hawks, and owls; endangered and threatened species such as California Condors and Whooping Cranes; and species of special conservation concern such as the Bicknell’s Thrush, Cerulean Warbler, Tricolored Blackbird, Sprague’s Pipit, and Long-billed Curlew.
One particularly interesting finding of the new study concerned the height of turbines. The scientists found that bird collision mortality increased significantly with increasing hub height. Across a range of turbine heights from 36 to 80 meters, the study predicts a staggering tenfold increase in bird mortality. This is especially important because the study identifies an apparent trend toward increased turbine height. Further, the study states: “This estimate (1.4 million) assumes that average wind turbine height will not increase. Installation of increasingly larger turbines could result in a greater amount of mortality.” Such an eventuality may be likely given that a Department of Energy report found that the average turbine hub height of U.S. wind turbines has increased 50 percent between 1998 and 2012.
The report offered several additional key observations about wind energy and bird mortality:
The mortality rate at wind farms in California was dramatically higher than anywhere else. According to the study: “We estimate that 46.4% of total mortality at monopole wind turbines occurs in California, 23.1% occurs in the Great Plains, 18.8% occurs in the East, and 11.6% occurs in the West.”
Failure to consider species-specific risks may result in relatively high rates of mortality for some bird species even if total mortality is relatively low.
Annual mortality estimates derived from a partial year of sampling may substantially underestimate mortality. Pre-construction studies should be conducted for at least one entire year prior to wind facility siting decisions.
The fatality records in the study identified at least 218 species of birds killed at wind energy installations.
Conclusions about collision rates and impacts of collisions on bird populations are tentative because most of the mortality data is in industry reports that are not subjected to peer review or available to the public.
Pre-construction assessment of collision risk at proposed wind facilities has been unreliable with no clear link documented between predicted risk levels and post-construction mortality rates.
“A key issue that was illustrated in this study, and one that we continue to have great concerns about, is data transparency and availability. While some companies may do the right thing and collect bird mortality data and make it available, others may not, especially if it is not in their economic interest,” Hutchins added.
The new study comes just after the Department of Justice announced a settlement on the prosecution of Duke Energy’s wind developments in Wyoming in connection with the deaths of 14 Golden Eagles and 149 other protected birds. That first-ever settlement resulted in $1 million in fines and mitigation actions and was the first prosecution of a wind company in connection with bird mortality.
This article was published by American Bird Conservancy (ABC), a 501(c)(3) not-for-profit membership organization whose mission is to conserve native birds and their habitats throughout the Americas. ABC acts by safeguarding the rarest species, conserving and restoring habitats, and reducing threats, while building capacity in the bird conservation movement.