I agree with geese being very close. Our 2 boys don't go anywhere without the other, I've never seen them apart and never seen them fight with each other. They literally stumble over each other while they circle and try to intimidate me. When they try to attack I usually bump them around and...
We have 2 African ganders (one without dewlap and one with) and they are MEAN. But they are very good foragers and protect our ducks so they earn their stay. I've gotten them to take treats out of my hand a couple of times and I catch them when they try and chase after me so they aren't all that...