You need to find a scarecrow in the shape of Wile E. Coyote, obviously.
I have cats running everywhere that have learned from day 1 that to hurt a chicken is to suffer greatly! Heck, my baby silkies peck the cats! BUT they know everything other than bunnies and chickens is fair game, and will stalk and hunt everything else, we had a hawk squalling in a tree last week and both my main cats climbed up that tree and stalked it, it left defeated and missing some feathers. So my cats are my scarecrows.