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Avian Mortality

Golden Eagles, named for the golden feathering at the nape of their necks, are majestic raptors that can be found throughout most of California and much of the northern hemisphere. California protects these magnificent raptors as both a species of special concern and a fully protected species, making it illegal to harm or kill them. Golden Eagles are also protected under the Bald and Golden Eagle Protection Act.

Golden Eagles typically prefer open terrain, such as the rolling hills of eastern Alameda County. The open grasslands, scattered oaks, and bountiful prey make this area ideal habitat for Golden Eagles. Today, it supports the highest-known density of Golden Eagle nesting territories in the world.

Conservation Issues

Every year, an estimated 75 to 110 Golden Eagles are killed by the wind turbines in the Altamont Pass Wind Resource Area (APWRA). Some lose their wings, others are decapitated, and still others are cut in half. The lethal turbines, numbering roughly 6,000, are arrayed across 50,000 acres of rolling hills in northeastern Alameda and southeastern Contra Costa counties.

The APWRA, built in the 1980s, was one of the first wind energy sites in the U.S. At the time, no one knew how deadly the turbines could be for birds. Few would now deny, however, that Altamont Pass is probably the worst site ever chosen for a wind energy project. According to a 2004 California Energy Commission (CEC) report, as many as 380 Burrowing Owls (also a state-designated species of special concern), 300 Red-tailed Hawks, and 333 American Kestrels are killed every year. In all, as many as 4,700 birds die annually as a result of the wind turbines.

Our Goals

Golden Gate Audubon is committed to reducing the levels of bird mortality at Altamont Pass to the greatest degree possible. In early 2004, Golden Gate Audubon joined the Center for Biological Diversity and Californians for Renewable Energy in a formal appeal to the Alameda County Board of Supervisors challenging the renewal of permits for 18 of Altamont’s 20 wind farms in Alameda County. The permits were reissued without requirements to decrease the bird mortality caused by the turbines and without environmental analysis under the California Environmental Quality Act. Golden Gate Audubon requested an environmental review of the permitting and urged the county to mandate that the wind industry reduce bird mortality. We subsequently sued the county and wind companies in order to force a reduction in avian mortality at APWRA. 

Reducing the kill entirely may not be possible, as long as the wind turbines continue to operate at Altamont. But we believe that significant progress can be made. The CEC estimates that wind operators could reduce bird deaths by as much as 50 percent within three years–the goal stated in our settlement agreement–and by up to 85 percent within six years–all without reducing energy output significantly at APWRA. These reductions could be achieved by removing turbines that are the most deadly to birds and shutting down the turbines during four winter months when winds are the least productive for wind energy, combined with some additional measures.

Golden Gate Audubon is working with Alameda County to ensure that the permits granted to the wind industry achieve reductions in bird mortality, in addition to other requirements that will help address the unacceptable bird kills at Altamont Pass over the long term. We also seek to support clean energy technologies, which help reduce the risk of global warming and its impacts on wildlife.

What You Can Do

Contact our East Bay Conservation Committee to find out how you can help support our efforts to protect Golden Eagles and other birds at Altamont Pass.