Branta canadensis

Various authorities recognize 8-12 or more subspecies. Generally tundra populations comprise small birds, whereas southern birds are much larger, with intermediate-sized birds in intermediate localities. Within these size groupings, birds from the Pacific coast tend to be much darker than are eastern birds. However, reintroductions from mixed stocks have greatly muddied the traits of many southern populations. (DeBenedictus, Birding, Dec. 1991). Northern populations of small Canada Goose have been variously treated as three separate species: B. hutchinsii, B. minima, and B. leucopareia; as a single species, B. hutchinsii; or as one or more subspecies of B. canadensis (AOU 1983). B. hutchinsii is now recognized based on genetic studies, including recent work with mitochondrial DNA (AOU 2004). Mitochondrial DNA data indicate that Canada goose subspecies fall clearly into two sister groups, large-bodied and small-bodied, which share no mtDNA types (Van Wagner and Baker 1990, Quinn et al. 1991); in contrast, nuclear-gene-encoded protein evidence associates all the subspecies very closely (Van Wagner and Baker 1986, 1990).

Breeds from central and southeastern Alaska east across northern Canada and southern Victoria Island to western Melville Peninsula, northeastern Manitoba, northern Ontario, northern Quebec, and southern Baffin Island (recently naturally established in western Greenland) south to southwestern British Columbia, northeastern California, northern Utah, south-central Wyoming, South Dakota, Kansas, northern Arkansas, western Kentucky, southern Ohio, Pennsylvania, northern Virginia, and Maryland. Breeding populations in the southern prairie states were extirpated, but many have become reestablished. Birds in eastern states south of Great Lakes and Massachusetts result from relatively recent natural southward extension of breeding range and to great extent from introductions. Feral populations resulting from introductions may occur almost anywhere in the United States (AOU 2004).

Winters from the southern part of the breeding range through most of the United States and into northern Mexico. Introduced and established in Great Britain, Iceland, southern Scandinavia, and New Zealand. Accidental in Hawaii, Greater Antilles, and the Bahamas.

Pesticide use is a potential threat; for example, 1600 died in a wheat field that had been sprayed with parathion (see Franson 1994).