The best protection is to lock your birds up safely at night. As far as guard birds go, geese are the best. They stay awake all night, & they're always eager to squawk when something alarms them. If you hatch geese with other birds, & raise them as one brood. The geese will protect the other species of bird as if it were it's own kind. My geese even let me know when a car pulls in the drive. & not to many critters are willing to mess with a goose.
