One of the chief concerns among wind opponents is the danger the installations pose to native wildlife. After all, these massive turbines spin at lethal speeds and the colossal structures take up large swaths of space that would otherwise be wilderness, or open flight paths for birds.
One particularly highly publicized wind farm, Altamont Pass in California, has been a lightning rod of controversy because of the impact poor planning has had on the bird population. According to the Center for Biological Diversity, as many as 1,300 eagles, falcons, hawks and other predatory species are killed each year because the wind turbines were constructed along a critical migration route.
Research conducted at other wind farms, however, has shown that bird populations have not been significantly impacted, and the National Academy Of Sciences has stated that bird fatalities from wind farms represent a fraction of the total number of bird deaths caused by humans [source: National Research Council].