Let's assume a turbine kills 4 birds per year [1]. Globally, 341,320 turbines are spinning around the world as of 2016 [2]. That's 1,365,280 deaths per year to generate roughly 4% of the world's energy [3]. Put another way, bird deaths due to wind power have been growing at 34% annually. That may make wind power one the fastest growing bird killers on the planet! It's especially worrisome if the birds affected are disproportionately large birds. I'm not quite ready to give the technology a free pass.

[1] https://m.phys.org/news/2017-06-farms-bird-slayers-theyre-be...

[2] http://gwec.net/global-figures/wind-in-numbers/

[3] http://windenergyfoundation.org/about-wind-energy/faqs/