According to a study in the Wildlife Society Bulletin, every year 573,000 birds (including 83,000 raptors) and 888,000 bats are killed by wind turbines — 30 percent higher than the federal government estimated in 2009, due mainly to increasing wind power capacity across the nation.[i] This is likely an underestimate because these estimates were based on 51,630 megawatts of installed wind capacity in the United States in 2012 and wind capacity has grown since then to 65,879 megawatts. And, at one solar power plant in California, an estimated 3,500 birds died in just the plant’s first year of operation.
Over the past five years, about 2.9 million birds were killed by wind turbines. That compares to about 800,000 birds that a Mother Jones Blog estimated to have been killed by the BP oil spill that occurred in April 2010[iii]—5 years ago–despite not all of them showing visible signs of oil. Nevertheless, BP was fined $100 million for killing and harming migratory birds due to that oil spill. In comparison, the nation’s wind turbines killed more than 3 times the number of birds than did the BP oil spill over the past 5 years. And, wind turbines routinely kill federally protected birds and eagles.
But hey, it's for 'green' energy, so it's worth it, right?