Jason, the Swans and Canada Geese here seem to eat separate types of food.
The Geese eat vast amounts of grass. The Swans spend their eating time in the shallow water, head right down eating off the bottom of the lake.
They both eat bread thrown by visitors, but thats not their major source.
Today this Swan had targetted one particular Canadian Goose. It chased it all around the park, passing feet from other Canadians, and ignoring them.
Very nice shot. That's some power.
I have a new theory John. Remember we remarked that the geese never seem to "gang up" against the swan.
It's possible the geese are playing a game of "keep away" -- a few keeping the swan occupied while others
get a chance at the prime feeding spots. Wondering what you think of this theory, from your observations.