Birds and Windmills
The Whirling Blades of Wind Turbines Can be Deadly to Birds
Anyone who has investigated the issue of bird mortality and windmills has heard of Altamont Pass, an area of rolling grasslands near San Francisco studded with 4000 wind turbines. Marching across the landscape in platoons and columns, the turbines, each with its whirling blades, resemble supersize barbed wire fencing. Estimates put the number of birds killed annually at Altamont Pass at 4,700, about 1,300 of them raptors (Golden Eagles, hawks, Burrowing Owls and other birds of prey).
Yet Altamont Pass seems to be the worst of the worst. The environment here supports high populations of ground-squirrels, and consequently high numbers of birds of prey. It is also situated in a migratory bird flyway. And because many of the turbines at Altamont are older models, with small rapidly turning blades, any birds that do fly near are more likely to meet with a sudden violent end. New windmills are much taller, lifting the blades above the flight paths of many birds, have larger, more slowly turning blades, and can do the work of four of the smaller turbines.
Studies of other wind farms have indicated that Altamont Pass is unusual – other wind turbines kill an average of about two birds a year. It’s true, too, that millions of birds are killed every year by automobiles, collisions with buildings and towers, feral cats, and habitat loss – many more than the number killed by windmills. Even more significantly, there is a high death toll resulting from oil exploration and drilling, air pollution, and climate change – all the result of burning fossil fuels. Though total numbers aren’t known with any accuracy, it’s possible that conversion to wind energy might bring a net saving of bird lives.
Although good studies of bird mortality at wind farms are few and far between, most proposals for wind farms now undergo some environmental scrutiny to minimize the chances of building another Altamont Pass. This is not to say that there isn’t still heated debate between environmental groups and energy companies, including suits before the courts, but progress is definitely being made. There’s one thing all sides can agree on: renewable energy from wind is a good thing if we can just make it work.
Sources:
Laumer, John. “Common Eco-Myth: Wind Turbines Kill Birds.” Treehugger; April 6, 2006.
Nijhuis, Michelle. “Selling the Wind.” Audubon. Sept – Oct 2006. Pg 54-60, 93.
Ritter, John. “Wind Turbines Taking Toll on Birds of Prey.” USA TODAY
Related content:
