Studies Show Wind Power Facility Impacts on Wildlife Vary, Although Notable Gaps in the Literature Remain and Few Studies Address Mitigation

Recent studies and interviews with experts reveal that the impacts of wind  power facilities on birds and other wildlife vary by region and by species. However, gaps in the literature make it difficult to develop definitive  conclusions about the impacts of wind power on birds and other wildlife. Such large numbers of raptor kills due  to wind power are not seen elsewhere in the United States. Studies Show That Bird and Bat Mortality from Wind Power in Other Parts of the Country Is Comparatively Lower Than in California and Appalachia

Results from studies on bird and bat mortality from wind power conducted  in areas other than northern California and Appalachia have not caused the  same degree of concern as in these two locations. Regulating Wind Power Facilities on Nonfederal Land Is Largely the Responsibility of State and Local Governments

Since most wind power development has occurred on nonfederal land,  regulating wind power facilities is largely a state and local government  responsibility. In the six states we reviewed, wind power development is  subject to local-level processes, state-level processes, or a combination of  the two. The federal role in regulating wind power development is  limited to projects occurring on federal lands or those that have some form  of federal involvement, such as projects that receive federal funding; to  date, there have been relatively few wind power projects on federal land. In  these cases, wind power projects must comply with federal laws as well as  any relevant state and local laws. Federal and State Laws Protect Wildlife

As with any other activity, federal and state laws afford protections to  wildlife from wind power. Three federal laws—the Migratory Bird Treaty  Act, the Bald and Golden Eagle Protection Act, and the Endangered  Species Act—generally forbid harm to various species of wildlife. While wildlife  mortality events have occurred at wind power facilities, the federal  government has not prosecuted any cases against wind power companies  under these wildlife laws, preferring instead to encourage companies to  take mitigation steps to avoid future harm. Regarding state wildlife  protections, all of the six states we reviewed had statutes that can be used  to protect some wildlife from wind power impacts. However, similar to  FWS, no states have taken any prosecutorial actions against wind power  facilities where mortalities have occurred. Various Wildlife Protections Are Provided by Three Federal Laws

The primary federal regulatory framework for protecting wildlife from  impacts from wind power includes three laws—the Migratory Bird Treaty  Act, the Bald and Golden Eagle Protection Act, and the Endangered  Species Act. Scientists, in particular, are concerned about the potential cumulative  impacts of wind power on species populations if the industry expands as  expected. Specifically, we assessed (1) what available studies and experts have  reported about the impacts of wind power facilities on wildlife in the  United States and what can be done to mitigate or prevent such impacts,  (2) the roles and responsibilities of government agencies in regulating wind  power facilities, and (3) the roles and responsibilities of government  agencies in protecting wildlife from the risks posed by wind power  facilities. We reviewed a  nonprobability sample of six states with wind power development— California, Minnesota, New York, Oregon, Pennsylvania, and West Virginia.
Why GAO Did This Study

Wind power has recently experienced dramatic growth in the United States, with further growth expected. However, several wind power-generating facilities have killed migratory birds and bats, prompting concern from wildlife biologists and others about the species affected, and the cumulative effects on species populations. GAO assessed (1) what available studies and experts have reported about the impacts of wind power facilities on wildlife in the United States and what can be done to mitigate or prevent such impacts, (2) the roles and responsibilities of government agencies in regulating wind power facilities, and (3) the roles and responsibilities of government agencies in protecting wildlife. GAO reviewed a sample of six states with wind power development for this report.

What GAO Found

The impact of wind power facilities on wildlife varies by region and by species. Specifically, studies show that wind power facilities in northern California and in Pennsylvania and West Virginia have killed large numbers of raptors and bats, respectively. Studies in other parts of the country show comparatively lower levels of mortality, although most facilities have killed at least some birds. However, many wind power facilities in the United States have not been studied, and, therefore, scientists cannot draw definitive conclusions about the threat that wind power poses to wildlife in general. Further, much is still unknown about migratory bird flyways and overall species population levels, making it difficult to determine the cumulative impact that the wind power industry has on wildlife species. Notably, only a few studies exist concerning ways in which to reduce wildlife fatalities at wind power facilities. Regulating wind power facilities is largely the responsibility of state and local governments. In the six states GAO reviewed, wind power facilities are subject to local- or state-level processes, such as zoning ordinances to permit the construction and operation of wind power facilities. As part of this process, some agencies require environmental assessments before construction. However, regulatory agency officials do not always have experience or expertise to address environmental and wildlife impacts from wind power. The federal government plays a minimal role in approving wind power facilities, only regulating facilities that are on federal lands or have some form of federal involvement, such as receiving federal funds. In these cases, the wind power project must comply with federal laws, such as the National Environmental Policy Act, as well as any relevant state and local laws. Federal and state laws afford generalized protections to wildlife from wind power as with any other activity. The U.S. Fish and Wildlife Service (FWS) is the primary agency tasked with implementing wildlife protections in the United States. Three federal laws--the Migratory Bird Treaty Act, the Bald and Golden Eagle Protection Act, and the Endangered Species Act--generally forbid harm to various species of wildlife. Although significant wildlife mortality events have occurred at wind power facilities, the federal government has not prosecuted any cases against wind power companies under these wildlife laws, preferring instead to encourage companies to take mitigation steps to avoid future harm. All of the six states GAO reviewed had statutes that can be used to protect some wildlife from wind power impacts; however, similar to FWS, no states have taken any prosecutorial actions against wind power facilities where wildlife mortalities have occurred.