Cutting out misc. shapes from ordinary black construction paper has cut back tremendously on bird strikes at our home. We have an abundance of large windows so needed to do something. We just have a single cutout, inside, in the center of each window and it helps a lot. Deaths are now very rare to none annually. For the sliding glass door that was getting hit, I cut out a pair of larger-than-life yellow owl eyes, and colored in a black pupil in the center of each. I used bright paint-color samples that stores carry for the circle cutout. Works great. They are paired on the outside of the glass. I have hung just a few silver/red shiny strips (used to deter cherry-eating birds) as well, but they fade fast and not sure they added additional protection, and the sun reflecting off them can be annoying. They are very useful, however, to show how breezy it is since they flutter so readily. Lona Pierce