I live near (and have volunteered at) a wildlife rescue. One of my cats is a savvy hunter and I was sick with guilt whenever she caught a bird 🐦. January of last year the intake person suggested I try a BirdsBeSafe collar available on Amazon. The minute I got home from dropping off the injured bird I ordered up a couple BirdsBeSafe collars and elastic safety collars to use with them.
This was the best purchase ever! My cats haven’t caught any birds since I put those collars on! It was easy to set them up, the cats weren’t bothered either. It is good to wash the collars every so often to keep the collar colors bright. They work by making the cats more visible to the birds so they see the cat lurking! Their cat camouflage doesn’t work!