Is there any way you could add a guard goose to the flock? They are soooooo vigilant, they won't stop a predator but they make a huge noise when a predator is lurking, most times enough to scare away most predators. Chinese geese are the loudest, from what I know. Anytime I go outside at night, my "biohazard breach alarms" raise a big racket (sounds like a biohazard breach alarm, as seen in movies)