We lost a chicken (Rhode Island Red - I think) about 5 years ago from a hawk- it was caught in the middle of the act and it took off just after it severed the head. Since then, (we have a fenced area off the chicken coop for the chickens to roam outside) we installed fencing over the top so nothing can get in, and nothing can get out, so the chickens are free to roam 24/7...