Safe haven ? We'll I guess I could have moved them all inside my house. My wife has already reached the conclusion that trying to keep have chickens and geese is impractical. Anyway, your solution doesn't address the question that was posed. I'm simply wanting to know what might have attacked my geese.
You could move them into an enclosed barn. You could have a cage with a top like SR suggested. There are lots of options instead of having sitting ducks. Oh the ducks are dead so they can't sit.