An at first very sad, but at the same time beautiful thing just happened. I heard the flapping and fluttering of wings and a rather desperate chirping sound coming from the window. We have those full-pane-wind-out-creates-a-V-space type windows and there was one little yellow bird trying to get back out but not finding the wide-open end of the V, and his/her friend on the other side of the glass frantically trying to help. I wound the window more open and the trapped bird was freed. And the two spiralled up happily into the sky. Then a few minutes later, flew back down, landed on the edge of the now wide-open window (safe safe safe) sang a sweet little song (of thanks?) then spiralled and chased off and away.