Cackling Goose

Historically the systematics of the bird formerly known as the Canada Goose were a mess. About 200 races of the bird were described in the literature. The situation is still not resolved, but is a bit clearer now. The smaller geese have been declared a separate species, the Cackling Goose. Genetic studies showed that these birds are not closely related to the larger ones and that there is limited gene flow between these size classes. Currently four races of Cackling Geese are recognized.

On 19 October 2020, Erika and I searched for Snow Geese among several hundred Cackling Geese at the Billy Frank Jr Nisqually National Wildlife Refuge. Most of the Cackling Geese looked like the bird in the first photo, but I slowly realized that many had dark chestnut breasts like in the second image. Two of the four Cackling Geese races are unlikely to occur here. The Aleutian Cackling Geese is a rare bird and usually sports a white white band at the base of the neck. The Richardson’s Goose winters mostly in Oklahoma and Texas and breeds in the eastern Canadian Arctic—it has a rounder head and lighter underparts than the bird in my first photo. Consequently I think the first photo is a Taverner’s Goose, which breeds in Alaska and northwestern Canada, and winters from Oregon to southern California. There remains the final Cackling Goose with the dark chestnut breast—a field mark of the Pacific Cackling Goose. These birds have very small bills and short necks. This race breeds in western Alaska and winters along the Pacific coast from Washington to southern California.