Fall is the bleakest time for predators, I think - there's not much around for the coyotes to eat. As a consequence, they seem to be spending more time near our sheep at night.
Last night, one of the folks who lives at our leased ranch heard coyotes about and our guard dogs barking. Buck, our oldest and most reliable guard dog (a Pyr-Anatolian cross) had all of his ewes bunched together and protected. We couldn't get along without our dogs!
We currently have four guard dogs. They live with the sheep and goats around the clock. In the daylight hours, they sleep. At night, they're all business. They don't like strange dogs, but they are very friendly with our Border Collies. They're amazing!