What the Duck!… or Goose?

I live on the Sacramento River and there are always Canadian Geese around, but every spring this one single different looking goose shows up. This goose will always be following a pair of Canadian Geese around. Once that pair of Canadian Geese’s goslings hatch and are full grown this other goose is gone for the rest of the year. I have no idea what kind of goose it is, where it comes from, where it goes for Summer, Fall and Winter, or why it follows these other geese around.  Do any of you Red Heads know this goose or have a clue of where it comes from? 

PS: He is very aggressive an one time chased me up my stairs coming home for lunch. From now on I always keep my eye on him…