By Bruce Batt, Ph.D.
Waterfowl managers recognize 19 different populations of Canada geese. One of these, the cackling Canada goose, breeds in one small part of the vast western Alaska landscape and nowhere else in the world.
Weighing only about three pounds, the cackling Canada is just a little bigger than a mallard and has a distinctive short neck, usually with a white neck ring. Its call is a brief, high-pitched unc.
Canada geese of the Atlantic Flyway population nest in northern Quebec. Weighing around eight pounds, they have the more typical look of Canada geese-large bodies, long necks, and light-colored breasts. Their call, a resonant uh-whonk, is longer and lower pitched than that of cacklers.
In southern Manitoba, the giant Canada goose weighs 12 to 14 pounds, a whopper compared to most other populations of Canadas, and it has the lowest-pitched and most prolonged call of any of the Canada geese. This is the goose many of us typically see in city parks and on municipal golf courses.
Each of these three populations is distinguished by size, plumage, and even by their calls. We would see additional diversity if we looked at the other 16 Canada goose populations throughout the continent. But the ducks are different-or should I say, not different.
Mallards in western Alaska look the same as mallards nesting in Saskatchewan, New York, Wisconsin, or northern California. You cannot tell where on the continent a mallard may have hatched (with certain exceptions; see It's a Deep Gene Pool on page 30), as you could with Canada geese, by looking at color variation or weight differences.