I’ve had a problem with songbirds, especially American Goldfinches, flying into my living room windows – the fixed portion and the casement windows on each side of it. Thankfully I’ve never seen one killed.
I bought a kit with a roll of clear tape which has small dots embedded every 2”. You install a length of tape the length (or width) of your window, use the supplied mini squeegee to press it down, peel off the clear tape and the dots are left behind on the glass. Move over 2”, install another length, repeat until the entire window has dots spaced 2” apart. The dots are a visual cue that this is a solid that you can’t fly through.
This is a huge, huge problem, particularly during migration seasons, in cities with reflectorized windows on mid- and high-rise buildings. Fatal Light Awareness Program (FLAP Canada).
https://flap.org
Before. To a bird this casement window looks like open air.
And after.
I do hope this helps.
previouslytexan 