A chaffinch hit our kitchen window this Spring- despite the cut out bird shapes stuck to it ... and it died instantly, blood pouring out of tis beak. We often have tits or sparrows hitting one of the windows- but not usually hard enough to do real damage
Those black bird cut outs on the windows are useless. The wintergarden specialist was at my house and he said they don't work. So I went out and bought a ton of string drapes to hang.
This user would like to thank Mrs. Doolittle for this useful post: