Wind power has long faced criticism for the threat it poses to birds – specifically endangered species. Experts estimate anywhere from 140,000 to 328,000 birds are killed each year by wind turbines.
California’s Altamont Pass wind farm has faced particularly harsh criticism due to the fact that its turbines sit very close together and kill an estimated 75-110 endangered golden eagles each year.
Yet new research suggests that golden eagles may be learning to navigate the dangers of wind farms. Scientists at the University of Northern British Columbia studied more than a thousand golden eagles for three years – during the year before a wind farm was constructed and the two years following its completion.
They found a statistically significant change in flight patterns once the turbines were erected. In the pre-construction year, a third of flights across the ridge went directly through the “risk zone,” the area where a bird could be struck by a blade. But in the two post-construction years, only nine of 148 flights entered the risk zone.
Clearly, once the turbines went up, golden eagles changed their flight patterns. According to researchers, most simply increased their altitudes and flew over the turbines rather than through them.
These findings don’t discredit the danger wind power poses to birds, but they do suggest that some birds may be more adaptable than we thought when it comes to recognizing and avoiding turbine risks.
More studies are needed to determine how other bird species adapt to strike zones. In the meantime, we must continue to take care when designing wind farms so that fatalities can be reduced.
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Eagles grow wise to wind farm hazards
Photo, taken September 24, 2008, courtesy of Jean via Flickr.
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Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.