I just got back from a roadtrip for work down to Tombstone, Tubac and Nogales. My DH texted me while I was gone that the neighbor (right across the small dirt road) lost about 20 ducks to a predator and the goose tried to fight it off. He found a duck head on our property. Thier animals are only behind a 4' high fence and there is a fenceline that runs in the same line as our property line that wildlife will follow (coyote, javelina, etc). Not sure what would be able to rip thru a duck neck, leave it and kill 20 ducks in one night. Our other neighbor also sharing that same property line lost her chicken flock to racoons last year I think. But I don't know that racoons could fight with a goose that well or even rip thru a duck neck let alone 20 duck necks.
We suffered no loss in our flocks. DH says the chicken fortresses held strong (so far).