I’ve lost a few ducks on my ponds to a hawk and a bobcat. I got on the waterfowl forums then, wondering if adding a goose would help protect the ducks. The consensus was that the goose would fall prey to whatever was eating the ducks, and that they require more specialized housing than what I wanted to provide. I do think people keep watch geese, but that seems a little redundant when I have guinea fowl! My guineas have gotten to be better watchdogs as they’ve gotten older. The last time that a bobcat went for a duck, the guineas gave me plenty of warning first.