I only let mine free range when both the dog and I can be out there to supervise. We have a pair of red shouldered hawks that live close by and stalk the yard. We also have fox, coyote, mountain lion, raccoons, eagles, etc. Someday I would love to have a larger property and some protective dogs to keep predators away, and the chickens could run around all day long. I really think free ranging is best for them if there’s a large property with lots of forage options. It also helps if the chickens have grown up free ranging, so that they are more predator savvy. If I suddenly let mine free range all day, they’d be knocked off by predators in no time. And on only 2/3 of an acre, there just isn’t enough forage.