The View from Sapsucker Woods

John W. Fitzpatrick

As a child I loved the friendly sight and gentle, creaking sounds of the windmills that dotted our landscape. Circular arrangements of aluminum plates mounted at off-plane angle, and guided by a large rudder, were fixed on high scaffolds to capture the Minnesota prairie breezes. Even by the 1950s these inexpensive water pumps already were being eclipsed by the national power grid, which brought reliable energy to farmhouses and electric pumps even on windless days. Today, a functioning old windmill is a rare throwback to pioneer America. But the wind still blows just as strong, and new, much taller silhouettes with rotating blades are appearing on horizons across the rural American landscape.

Wind turbines today produce about 1 percent of our energy, both in the United States and worldwide, but these numbers are changing fast. Global production of wind-generated power has quadrupled since 2000. In the U.S., a growing number of states are passing environmental laws requiring that a significant percentage of their new energy sources draw on renewable resources (e.g., California demands 20 percent by 2010). With mounting concern over oil reserves, carbon emissions, coal-burning, and global warming, the world is literally buzzing over wind.

But clouds hang over the wind turbine. In Massachusetts, a plan to build the nation's first major offshore wind farm on Horseshoe Shoal in Nantucket Sound has roused thunderous debate over potential effects on wildlife, tourism, and economics. At Altamont Pass, east of San Francisco, the world's largest wind farm has slaughtered large raptors (especially Red-tailed Hawks, Golden Eagles, American Kestrels, and Burrowing Owls) literally by the thousands, and is widely regarded as the single worst disaster haunting the wind-power industry. In southern Mexico, a plan is rapidly unfolding to erect an enormous array of wind turbines atop mountain ridges over which millions of raptors migrate each year. Will this be Mexico's Altamont Pass?

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Do we have to choose between birds and wind energy? Amid much hot air on both sides of this debate, research is beginning to shed light. Perhaps the most important finding is that the exact site matters a great deal. The Altamont Pass wind farm was placed on windy slopes in an area with extraordinary densities of raptors and their prey, along a raptor migration corridor. No other wind farm in the country has come even close to the scale of bird fatalities at Altamont. Modern turbines also rotate much more slowly than the original versions at Altamont, acting more like ceiling fans than Cuisinarts and greatly reducing the potential for collisions. At many, perhaps even most modern wind farms, bird collisions appear to be rare. Recent evidence from radar tracking shows that migrating songbirds actually see and avoid wind turbines even at night, often gaining elevation and flying over the top of them. (Migrating bats may be a bigger problem than birds, because they appear to be much less capable of detecting and avoiding the rotating blades.)

Hope is building that, although bird collisions are impossible to eliminate altogether from wind turbine arrays, modern designs and site restrictions can keep strike frequency well below levels that could affect bird populations. As upcoming generations grow familiar with these windmills of the future, the key is to keep vigilant that detailed research be funded by the proposal themselves. Money must be built into each and every wind-farm project for careful and independent follow-up study of its local environmental effects. Tomorrow's energy will be safer only if we force ourselves to keep learning from today's experiments.

—John W. Fitzpatrick, Louis Agassiz Fuertes Director

For permission to reprint all or part of this article, please contact Laura Erickson, editor, Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, NY, 14850. Phone: (607) 254-1114. email: lle24@cornell.edu