KKcatknap is correct your predators will be snakes, coyotes, neighborhood dogs, hawks, and owls. Don't allow the chickens out in the yard alone until they are full grown or else hawks will take them. I live in the 35th ave/ Deer Valley area and we have coyotes that roam the neighborhood occasionally at night. I have had many people tell me they are concerned with feral cats as well but I have yet to see one bother full grown birds.