7000 windmills x 20 years = 140,000 windmill years. Divide 22,000 bird deaths by 140,000 and we get .16 birds/windmill/year. Hard to see where there's a lot of room for improvement.
I think I saw that many starlings in a flock last year in NC. I see nothing to be worried about. Besides, these generators are not flying, they are rotating, and not all that fast. Crying about nothing.
Glass windows kill more birds each year, when birds try to fly into them!