Bird collisions with turbines and associated infrastructure are increasing yearly, and annual bird mortality is projected to reach more than 1.4 million by 2030. Challenges include voluntary guidelines that are often ignored, leading to a lack of transparency and poor siting of turbines.

Birds are unaware of the threat of turbines. Photo by Bildagentur Zoonar GmbH/Shutterstock

Wind Energy and Birds: Are They Compatible?

Bird mortality related to poorly sited wind energy infrastructure is growing. The annual loss of birds from wind turbines in the United States was estimated to be around 681,000 as of 2021; more than 1.4 million bird deaths are projected by 2030 or earlier if the U.S. meets its goal of producing 20 percent of electrical energy with wind.

If that figure reaches 35 percent, as Department of Energy projections suggest, up to 5 million birds could be killed annually. (These estimates do not include birds that are killed by collisions with associated power lines and towers, which could be in the hundreds of thousands or even millions annually.)

Raptors like Golden Eagles and nighttime migratory songbirds including Yellow-billed Cuckoos, Golden-winged Warblers, and Kirtland’s Warblers are particularly vulnerable.

Wind energy poses special risks to endangered or threatened species such as Whooping Cranes and California Condors, since the loss of even a few individuals can have population-level effects.

Birds can also be impacted by habitat destruction and disturbance resulting from construction of turbines and access roads. Some birds, such as Greater Sage-Grouse, are very sensitive to the presence of turbines and can be scared away from their breeding grounds up to several miles from a wind development.

Short-eared Owl, Ashok Khosla

The Problem of Voluntary Guidelines

The U.S. Fish and Wildlife Service (FWS), operating under the Department of Interior (DOI), maintains oversight of wind energy development’s impact on protected wildlife through the Endangered Species Act, Bald and Golden Eagle Protection Act and Migratory Bird Treaty Act.

FWS has developed voluntary wind energy guidelines that are intended to protect wildlife from poorly-sited and -managed wind energy facilities. Unfortunately, these voluntary standards are not adequately protecting our public trust resources, including birds.

Tundra Swans, Delmas Lehman/Shutterstock

Lack of Independent Risk Assessment

FWS’ voluntary guidelines call for pre-construction studies to assess the risk to federally-protected wildlife. Often these assessments consist of on-the- ground surveys, combined with a search of the existing literature on the area’s wildlife and habitats.

However, these assessments are typically conducted by industry-hired consultants. We consider such non-independent analyses of risk to be a conflict of interest. Indeed, ABC and others have noted several cases of paid consultants downplaying the potential risk to wildlife so that their clients can obtain the necessary permits and begin construction, including at least two cases in Minnesota.

This is highly problematic since, to our knowledge, no wind energy company has ever been shut down post-construction, not even the notorious Altamont facility that has killed thousands of federally-protected birds.

Snowy Owl flies toward a wind turbine. Photo: David A. Krauss.

Lack of Transparency

In spite of the fact that U.S. citizens have a right to know what happens to birds at wind energy facilities, a pervasive lack of transparency makes this information difficult or impossible to obtain.

For example, in June 2013, in an effort to obtain bird mortality records, we sued DOI for violating the Freedom of Information Act. Although we received some of the information, problems remain. Under the voluntary system, wind energy companies are solely responsible for reporting bird deaths at their facilities. As a result, FWS and the wind industry consider bird kill data the property of the companies and treat it as if it were a trade secret.

We believe that, whether on public or private land, our nation’s birds do not belong to wind energy companies. They belong to the American people and are held in trust for this and future generations.

Golden Eagle, Stewart Dawber/Shutterstock

The Problems of Self-Reporting

Self-reporting of bird (and bat) fatalities continues to be a major conflict of interest, especially since wind energy companies may be subject to expensive fines, mitigation, or prosecution if they are forthcoming. We believe it is time for independent monitoring of bird deaths at wind energy projects.

Despite widespread bird and bat deaths, only two wind energy companies—Duke and Pacifico— have been prosecuted for killing protected wildlife. In November 2014, Pacifico sued FWS to keep information on bird kills secret.

We continue to ask, how is it possible to evaluate the effectiveness of siting or mitigation, or to calculate reasonable compensation for any losses, in the absence of such information?


Whooping Crane, Al Mueller/Shutterstock

Turbines in Sensitive Bird Areas

It is becoming increasingly apparent that FWS’ voluntary guidelines are not working to protect our ecologically-important birds and bats. A recent study funded by ABC and conducted by Mississippi State University overlaid U.S. Geological Survey and Federal Avian Administration maps that show existing and proposed turbines with our Bird Risk Assessment Map that shows the location of important bird areas.

The results indicate that tens of thousands of turbines already exist in sensitive areas for birds and tens of thousands more are planned. This includes 5,500 existing and 18,500 planned turbines (plus associated power lines and towers) in the migratory corridor of the endangered Whooping Crane.

Red-winged Blackbirds, Erni/Shutterstock

Inability to Estimate Cumulative Impacts

Another weakness of the current voluntary guidelines is that there is no way to assess the potential cumulative impacts on bird populations. The impacts of wind energy are often being assessed one project at a time, even when several projects are being considered for the same area.

Models are being developed to help estimate cumulative impacts, but until their validity can be tested for accuracy, this amounts to a big experiment with our nation’s wildlife in the balance.


California Condor, kojihirano/Shutterstock

Problems with Mitigation

Mitigating — or offsetting the impacts of — wind energy development is an important aspect of FWS’ voluntary guidelines. Some types of mitigation for wind energy include the use of radar or observers to detect the presence of large flocks of birds and then shutting down turbines temporarily or seasonally (e.g. during peak migration) and avoiding lighting that attracts birds or bats at night.

Unfortunately, with few exceptions, such as ultrasound deterrents for bats, these methods have not been systematically tested for their efficacy. Until rigorous testing occurs, there is no way to know whether or not they are effective in reducing wildlife deaths.

The Department of Energy’s Office of Energy Efficiency and Renewable Energy recently stated that, “…technologies to minimize impacts at operational facilities for most species are either in early stages of development or simply do not exist.”

Read more about mitigation testing.