Friday, November 12, 2010

Cackling Goose

While taking photographs of Canada Geese (see first photo) in the Cannon River within the city of Northfield, I noticed that about a quarter of the flock were smaller and tended to stay away from the larger geese.  The smaller birds' bills are relatively shorter and stubbier, giving the bills a triangular appearance (see middle photo).   Additional field marks add up to the small birds being Cackling Geese. 
1. In the photo at the end of this post, a Cackling Goose swims in front of two Canada Geese.  The head is not as round as in the middle photo above, but not as wide as in the Canada Goose.  (The Cackling Goose in the bottom photo shows kind of a squarish, rather than round, head--but that is OK.)

2. The forehead of the Canada usually has more of a slope to it than does the more angled Cackling forehead.

3. The Cackling Goose tends to have a relatively shorter neck--a field mark that is apparent in the lower photo, but murky if the bird is stretching its neck out as in the middle photo.

4. Cackling Geese show slightly darker breasts than do Canadas, a mark that can be seen in the photo below. 
Until recently, Cackling Geese were considered to be a small race of the Canada Goose.  Genetic studies indicate that the two forms are distinct species.  Paul Hertzel, Ross Silcock and Stephen Dinsmore have published a website that further discusses identification issues with these geese. They warn that not every Cackling Goose, especially when solitary, is easily identified.

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