Energy use has a dramatic impact on wild bird populations.  In the United States, the fastest growing source of electricity is generated from the wind.  Want to know how wind farms impact birds using your bird feeders?  Read on.

Wind Energy
As the population of the United States grows, so will the demand for electricity.  In recent years, many states have required that a certain percentage of their energy be derived from renewable energy sources, such as wind.  Energy harvested by the wind does not emit greenhouse gasses or hazardous pollutants such as mercury into the atmosphere, and thus, wind energy is considered far less harmful to the environment than other forms of electricity, such as that derived from burning coal.

Wind Farms can Impact Bird Populations
The presence of wind turbines can negatively impact bird populations, particularly if turbines are not properly placed.  First, birds may die by flying into wind turbines.  For example, the large-scale wind farms in Altamont Pass, California, annually account for a considerable number of raptor fatalities.  In Buffalo Ridge, Minnesota, fatalities at a wind farm have included passerines, water birds, ducks, upland gamebirds, raptors, and shorebirds.  Birds may also perceive turbines as a disturbance and avoid an area the species would normally occupy.  In southwestern Minnesota, researchers found densities of grassland birds in fields without turbines were greater than in locations within 80 meters of turbines.  Finally, the construction of turbines, access roads, and associated infrastructures may result in loss of bird habitat.

Evaluating the Impacts of Wind Farms on Birds
In order to determine whether proposed wind farms will have an adverse impact on bird populations, it must first be determined whether proposed wind farm areas contain bird populations that are endangered, threatened, or considered of local importance.  Information is needed about where a wind farm would be located relative to migratory flyways and if the area serves as a stopover site for migratory birds.  Scientific studies should examine bird mortality at pre-existing wind farms of similar configuration to the proposed ones and compare the number of birds at pre-existing wind farms with the number of birds in equivalent non-turbine habitats to fully assess the impact.  After construction, mortality surveys should be conducted to determine if there are any turbines that are particularly harmful. 

Are Wind Farms Bad for Birds?
When evaluating the impact of wind farms on birds, it’s important to consider the impact that other structures and other energy sources have on birds.  For example, the estimated number of fatalities per turbine per year of less than 1 to 7.5 is within the range of the estimated 1 to 10 fatalities per building per year due to bird-window collisions. Over 50% of U.S. electricity is derived from the burning of coal.  The use of coal and other nonrenewable resources adversely impacts bird populations by contributing to global warming, promoting acid rain, emitting mercury, and causing the loss of thousands of acres to mining activities.  Wind turbines can also fragment the landscape, serve as a disturbance, and result in direct mortality of birds.  With careful planning, however, the impact of wind turbines on birds can be substantially minimized.