Every once in a while someone will report a cat killing a chicken in the predator/pest section. Personally, I've never seen it and we have had a variety of cats as well as feral ones over the 25 years that haven't harmed adult birds. I did lose a couple of fuzzy chicks to a cat back the first year I kept them--was brooding on the floor in the cellar and left the door open to the room they were in. Once those birds feathered out, that cat left them alone. An adult, heavy breed of chicken would be a pretty tough kill for anything but a really big cat. I've lost free ranging birds to dogs, coons, possums, weasels, foxes and hawks but never a cat.