Reported here in early 2015:
Now, federal wildlife officials are cracking down on wind farms caught killing bats and birds. A peer-reviewed study issued last summer estimated turbines kill as many as 368,000 birds annually. ... House cats kill at least 1.4 billion birds annually, and possibly up to 3.7 billion birds, according to a 2013 federal study. And a single natural-gas flare at a liquid natural gas plant in Canada killed an estimated 7,500 birds in a single night.