Ian - may I suggest it was possibly a leucistic Canada (a bird with partial white plumage) rather than a hybrid.  I suggest this after recently banding my second leucistic Red-tailed Hawk in NY.

Bob Yunick
Schenectady, NY

-----Original Message-----
From: Ian Worley <[log in to unmask]>
To: VTBIRD <[log in to unmask]>
Sent: Sun, Feb 26, 2017 1:37 pm
Subject: [VTBIRD] Snow Goose x Canada Goose hybrid .. Lemon Fair WMA, Cornwall.

While beginning to count 2300 Canada Geese today in the flooded Lemon 
Fair River flats west of West Street, Cornwall, I came upon a noticeably 
large goose, as compared with the Canada Geese and one Snow Goose it was 
foraging with.  I was struck by its size, but it didn't really look like 
any domestic goose with which I am familiar.  I now think it is a Snow 
Goose x Canada Goose hybrid.

As I was taking notes on its plumage, the ensemble of geese bolted as an 
immature Red-tailed Hawk made a zooming pass.  They landed about 0.3 
miles up stream with other geese at a location I could not see well.

I saw the bird from right and left rear quarter view as it swam and when 
it took flight.  It was dark bodied above, and white below.  The wings 
were dark but the outer primaries were all white and very striking in 
flight. My look at the neck was remembered poorly, though it definitely 
was not white.  The head was prominently pied in color, a mottling of 
dark spots or blotches on a white field.  I did not see the bill or feet 
with any clarity.