I have tons of predators. When I went out this morning to let my birds out, there was our resident coyote sniffing around outside the fence. But in the three years he has been around, he has been unable to get inside our electric poultry netting. No doubt he has touched it, and now respects it quite well. My method is mobile coops that I close at night, electric poultry netting with a solar charger that is easily moved and which my birds free-range inside, and at times a field fence around all that (when the birds are in my orchard....I have a 6 foot high field fence to keep out the deer). I have the following predators and have had no predator loses over the past 4 years......coyote, cougar, occasional bear, mink, weasel, raccoon, hawks, owls, bald eagles, neighborhood dogs.
That is just what works for me. I am a very big advocate for giving birds as much space as possible, in order to minimize stress and behavioral issues. In a 15x30 foot permanent pen I personally would keep no more than 6-8 hens who were all raised together and got along well....but that is just me.