Systematics: Subspecies
Four subspecies, following Delacour and Zimmer (1952); see also
Carboneras (1992). A more conservative, and traditional, treatment is to recognize three subspecies (e.g., Dickinson and Remsen 2013), but to do so ignores a distinct population that breeds in the high Arctic of w. Canada for which a name is available (Buckley and Mitra 2002). Yet even the treatment below is provisional, as it accepts Buckley and Mitra's (2002) position that the type specimen of
B. b. nigricans—from New Jersey even though the name was applied to Pacific birds—can be equated with otherwise unnamed breeders in the high Arctic of w. Canada. Moreover, this taxonomy better jibes with geographic and genetic divisions of breeding and wintering populations (Boyd and Maltby 1979, Reed et al. 1989a, Sedinger et al. 1993).
B. b. hrota (Müller, 1776), the Atlantic Brant, Light-bellied Brant, or Pale-bellied Brent Goose. ...
B. b. bernicla (Linnaeus, 1758), the Dark-bellied Brant or Dark-bellied Brent Goose. ...
B. b. orientalis Tugarinov, 1941, the Black Brant. Includes
B. torquata (Blakiston and Pryer, 1878), and
B. b. orientalis Tugarinov, 1941. Breeds from low Arctic of w. North America to high Arctic of e. Russia [type locality = e. Siberia]; winters along the Pacific Coast, from se. Alaska to central Baja California (Bellrose 1980, Subcommittee on Pacific Brant 1992, Sedinger et al. 1993). Broadly similar to
B. b. bernicla, but belly blackish (contrasting little with breast and extending past legs), white fringes on flanks broad but restricted to rear flanks to form a distinct white patch, dorsum fuscous (i.e., blacker brown), and necklace wider and typically complete.
B. b. nigricans (Lawrence, 1846), the Gray-bellied or Lawrence's Brant. Includes
B. torquata (Blakiston and Pryer, 1878). Breeds on the Parry Islands (Melville, Prince Patrick, and Borden) in the high Arctic of w. Canada and winters chiefly on Puget Sound (Boyd and Maltby 1979, Reed et al. 1989a), although a few winter records are from the Atlantic Coast (Delcour and Zimmer 1952, Buckley and Mitra 2002) [type locality = Egg Harbor, New Jersey]. Similar to
B. b. orientalis, but belly dark gray (contrasting more with black breast) and less extensive (terminating at legs), upper breast and flanks "scaly" (like on
B. b. hrota), and white fringes on flanks broad and more extensive, and necklace wider and typically complete.
