I may have to eat my words, but so far I havn't really had any predator problems and my fencing is "adequate". An outer perimeter of link fence, then a coop of chicken wire and a wooden box inside the coop that is secured for sleeping.
I think my main source of security is an annoying but effective beagle. We see very little wild life because of the dogs. I've heard fox calls so I know they are there but haven't seen them.
Actually, my daughter saw the beagle playing with a fox at our last house. He was living wild himself before I caught him and there was a fox family we often saw. No chickens at that time--just a bird feeder with squirrels. The fox sat at the foot of the tree in broad daylight looking longingly up at the squirrels.
This was in Atlanta. How I loved that place on the river until we got flooded out.
Sorry to have yammered on.
Bottom line----dogs for security.