I have had chickens for 6 years now and have free ranged them for 5 years. In those 5 years I have lost (to a predator) a total of 3 chickens. Predators in the area are hawks, eagles, owls, possums, coons, mink, bear ect. The chickens go in at night and are locked up tight. The key here is to have as many hiding spots as possible. Trees, truck toppers, boats, trailers, bushes, dog houses, anything you can think of they hide under. Put em out in an open field and it will be an all u can eat buffet especially for the flying predators