The rooftop sides of our house are pure glass with wooden frame structure. I remember, as a kid, when birds would try to fly in not noticing the glass and ending with a loud thump on our balcony. Depending on the speed and the angle they hit the glass front they ended up in a wide range from broken neck and dead to just dazed. My parents had those stickers of large birds of prey silhouettes on every big window and they helped a lot. About 10 years ago they were coming off and I replaced them with Space Invaders …. off course! 😉 A few birds still don’t seem to notice and so we do have impacts from time to time.
The most prominent was a woodpecker who’s brain is luckily made for taking a hard bang. He was just dazed and when he regained his consciousness back poked me right in the hand – completely different type than those pigeons that do it usually. Pigeons tend to give in to their fate and once you got hold of them don’t seem to fight. Guess this one had a hard time recovering, if it did at all. There was the whole head, body wings – you could see every wingtip) on the window. I had a hard time capturing it and only partly succeeded, but will probably try it again.