Colonel Sam's/Humber bay park east

[American Redstart]

Today at Colonel Sam's, I saw:
Canada Geese
''Lesser" Canada Geese
Mute Swans
Gadwalls
Mallards
Greater Scaup
Long-tailed Ducks
Buffleheads
Red-breasted Mergansers
Ring-billed and Herring Gulls
Mourning Doves
Black-capped chickadees
European Starling

and added ruddy ducks and a northern cardinal at humber bay.

[American Redstart]

The lesser Canada goose could've been a cackling goose.
What are the differences?
I saw a small Canada goose.