Goose Goose protects 'her' ducklings with impressive ferocity. I've tried for weeks to get a decent photo, but of course, she spots me and the camera and turns into a sweetie. So this is as good as it gets.
When geese go into protective mode, they stretch their necks straight out, holding their heads low while they hiss and stalk toward whatever they perceive as a threat. (Unless it's REALLY big and scary -- honk, honk, run!) That's a warning, and most creatures back off. Especially if they've ever been pinched by that strong, hard beak. They'll also fly at your head and beat you with their wings. That hurts.
Actually, all three of the Buff Orpington geese take turns watching over the ducklings. The mated pair often have 'other business' to attend to, though, which leaves Goose Goose in charge much of the time. She doesn't seem to mind as she has few other demands on her time. The white rooster she adores apparently has made it clear that they're just friends.