'I have had a flock for a little over year. I started out letting them free range during the day in a large wooded fenced in back yard. Everything went fine for the first couple months. I went out of town and a neighbor was managing them, locking up the predator proof pen at night after they roosted. One of them vanished into thin air while I was gone. We never found a trace of her inside or outside the fence. I loved having them free range, loved watching them scratch and peck. I could walk out on the deck and they would come running to me. I added to the flock replace the missing bird and within a week, another loss. This time I found her body, of course mutilated, inside the fence. General consensus was a hawk. I was aware I had hawks, but thought there was plenty of coverage for them to run to. I didn't learn my lesson yet. However, I put a "baby" monitor in the back yard where I could hear everything and only let them "free range" when I was home and could listen out. Not good enough, I was home, had the monitor on was sitting in the sunroom right off of my deck when I heard a lot of clatter. I ran outside to see the *****hawk penning one of my hens to the ground, right there in full view. He flew off immediately and she lay there motionless, presumably dead. I gathered the rest of the birds and went to retrieve the dead, injured, or dying bird. As soon as I got up to her she jumped up and ran off uninjured!!! Smart girl was playing dead and I got there just in time. I'm sure in seconds she would have been the third kill.
So I finally learned my lesson, and we went to a great deal of effort to enclose a large "exercise" area outside the pen with fence and bird netting overhead. We made a window out of the pen where the flock can go in and out all day. Then at dusk we shut the window to Fort Knox. I'm glad to report we've had no problems since then. I still am tempted to let them out from time to time, but resist the temptation. They seem happy and egg production is good. I have several neighbors that let their flock free range with a rooster and they just don't worry about it.
So you must way the pros and cons and evaluate what predators might be a threat. I don't think there is any protection from a hawk except completely enclosing an area as we did. I would be happy to send you a picture of our setup. I don't think I can attach it here however.
Good Luck!