The swans and geese are very territorial, they seem to get along in early spring when there is just a little space available but when it comes nesting time they want space, lots of space, and it ends up in quite a performance on the bay....the swan ruffles up and chases after the fast fleeing goose...then the goose turns and honks and wing flaps furiously at the swan, chasing it for a while, then the swan turns and the dance continues. For all the flapping and honking and fuss they make, not a feather is hurt and nobody actually tackles the other, mere gesturing and posturing for position. The females (and babies if they have them) simply step aside while all this is going on and it's strictly male swan versus male goose.
Here is a picture from last years duet....
