Are offshore wind turbines a danger to bird populations?
Worries about the effect of turbines on marine wildlife, especially birds, have been voiced by some skeptics. So, what are the facts?
Researchers have conducted a number of studies and found that while wind turbines do account for some bird deaths — estimates run from 20,000 to more than half a million in the entire United States — even the most dire estimates suggest that wind turbines are responsible for only a fraction of the number of bird deaths caused by other factors, including collisions with buildings.
In Toronto alone, as many as 9 million migrating birds are killed in collisions with buildings, according to a study by the Fatal Light Awareness Program (FLAP). In the U.S. collisions with buildings kill hundreds of millions of birds each year in the U.S.
Hunters kill from 100 million to 120 million birds annually in the U.S., while transmission lines kill about 175 million. Meanwhile, feral and domestic cats may kill as many as 3.7 billion birds in the U.S. each year, according to a study by British scientist Benjamin K. Sovacool.
Other research has found that the gravest danger is from continued release of greenhouse gases and the resulting climate change. Mark Urban of the University of Connecticut wrote, “If greenhouse gas emissions continue unabated, 16 percent of species will be threatened with extinction due to climate change by the end of the century.” He based that on an analysis of 131 separate studies on the topic.