Birds and wildlife

Sometimes birds have been killed by flying into wind turbine rotors. In California, golden eagles and other raptors have died or been injured from electrocutions or collisions with spinning rotors at Altamont Pass, one of the world’s first wind farms. Most turbines in North America, however, have low impacts on birds. Studies by the U.S.-based National Wind Coordinating Committee indicate an average bird kill of two to three birds per turbine each year.

Wind power developers take different actions to minimize risks to local and migratory birds. Current wind turbine technology offers solid tubular towers to prevent birds from perching on them. Turbine blades also rotate more slowly than earlier designs, reducing potential collisions with birds. Electric utilities and wind developers use preconstruction surveys to indicate whether birds or other wildlife may be affected by wind turbines. They consider the location of common migratory bird routes and, wherever possible, avoid those areas for wind farms. Once a project is constructed, developers also carry out environmental monitoring to minimize impacts to local birds and wildlife.

Bat fatalities have recently become an issue in the wind power industry because fatalities have been documented by post-construction wildlife surveys at some wind farm sites across North America. Because of these fatalities, the wind power industry is carrying out studies to better understand this issue.