Since I improved the coops and run and started free ranging, I've only had predator losses in daytime.
The first year was awful: I had 7 losses to predation (4 chickens to a bobcat, 2 guineas to a coyote, 1 pullet to a hawk, and one chicken probably to a coyote).
Year two went better in some respects: 3 chickens lost to hawk attacks, one guinea to something relatively small (fox or raccoon sized, or maybe a small dog) that burrowed under the fence and dragged it through.
I'm 10 and a half months through year 3 and only lost one chicken to a hawk attack so far.
Replacing the half of the fence that was 20+ years old and beat up, as well as being more vigilant about fence maintenance in general seems to be the primary deterrent for the coyotes. This is especially true after I caught one trying to get at the guienas through the fence and shot at at. They seem to avoid the fence since then, and I've actually seen them run when the guineas raise the alarm.
I spent two weeks stalking the bobcat, heard it in the brush a few times, and even found its den. It left the property a week after that and has since com back but sticks to the waterways that border the property.
The birds of prey are the most persistent problem, especially fall and spring. The three that live on and around my property have largely given up, especially after one got beaten up by the guineas. The real troublemakers are the migratory hawks: they've accounted for most of the losses since the first year. They're a lot hungrier and more persistant than the locals.
I did have a weird situation last year when the opossums got overpopulated and started nosing around the house in daytime. A couple times the birds managed to drive them off, then after I culled a few they kept to the night-time.