Wonder no more, it is more likely that those ads were paid more by astroturf groups.
As for the numbers, they are a concern, but remember about the canary in the coal mine? Many more than the ones affected by wind turbines do not have to be in the mine to die thanks to the pollution coming from fossil fuels.
http://thinkprogress.org/climate/2014/08/25/3475348/bird-death-comparison-chart/
Oh, and put a bell on your cat. You will save more birds that way.