A couple years ago, i tried a vatiation on "zen curtains" using standard hemp twine rather than parachute cord.
Basically, you hang the cords 2 inches apart which, apparently is the distance that birds won't fly through. Have had only 2 strike deaths in last two years and used to average 1 monthly. Cords don't significantly interfere with looking through window.
Can find videos on uTube, can you believe.