Wind turbines and migratory birds: A serious problem?

Wind turbines are responsible for the deaths of between 10,000 and 40,000 birds each year, according to the American Bird Conservancy.

Debate over the significance of the threat turbine blades pose to migratory birds is about as old as the concept of wind farms themselves. It began in Altamont Pass, Calif., site of one of the first U.S. wind farms, where there were more than 4,000 turbines. Hundreds of bird carcasses were found on the farm grounds, leading bird conservationists to propagate information that wind turbines were inherently deadly to birds.
While the Altamont Pass site kills the largest number of birds – about 4,700 each year, as reported by USA Today – the wind farm sits on a major migratory route for small birds. The latticework blade-model turbines the farm uses are also outdated for energy generation purposes and have been found to actually attract large birds of prey, which use them as perches. Latticework blades have been abandoned by turbine designers in favor of thinner solid blades with slower speeds.

The American Wind Energy Association contends wind turbines are far less lethal to birds than other man-made structures, such as windows (responsible for more than 100 million deaths each year in the U.S.) and power lines (between 130 million and 174 million), or than cats, which remain the number one bird killer.

The Illinois Department of Natural Resources conducted a study in 2007, which found far fewer instances of bird deaths from wind turbines than some feared. The mortality study, conducted at a wind energy installation, found an average of one bird per turbine was killed a year.

However, bat deaths associated with turbines were three times that of the rate of birds, especially during their migratory season, IDNR’s study recorded.

The Southern