Cackling Goose "Richardson's" subspecies Branta hutchinsii hutchinsii Andrew Haydon Park, Ottawa, Ontario 2 December 2009 Here is a good comparison shot of a cackling goose (foreground) and a Canada goose (background). Although the cackling goose is slightly closer to the camera than the Canada geese, it is still easy to see the difference in size between the two species.
Cackling Goose "Richardson's" subspecies Branta hutchinsii hutchinsii Andrew Haydon Park, Ottawa, Ontario 2 December 2009