As for myself, we have woods all around the property, foxes, coyotes, hawks, eagles, and owls. Our farm dogs keep the ground predators at bay. I hear them every night and we saw one several years ago, but not since they got chased off by my Greyhound. and the family of crows that live on our farm and that I feed, keep the flying predators away. It's rather funny watching an eagle trying to be dignified with four crows harassing him till he's gone from our airspace lol. My roo also considers the crows, (and tweetybirds), to be predators, but it's worth it for the security they give freely. Also my "free range" hens have a 5,000sq ft fenced yard, 120sq'/bird that has a foot of welded wire outside the fence on the ground to prevent digging.
(To be technically "free range" a bird needs 108 sq ft. That's what each bird requires so that they don't eat all the plants, I give mine 120 sq' each, and am always expanding)
Then again is my rooster, he is not lazy like that other posters roo, who let the fox in, my rooster has tore up a hawk that got past the crows. I came outside to the sound of birds fighting and saw them. The hawk had landed trying to catch a chick, and I saw my roo ripping him apart with vengeance. That hawk flew away missing half his feathers, and hasn't tried again. So I use a combo of fenced pasture with anti digging wire on ground outside, LGD, friendly crows, and a roo that's worth a damn. I haven't lost a single bird in 20 years because of this combo.
I also think the electric wire outside the fence is a great idea too. Good luck whatever method(s) you choose.