Branta bernicla

Includes B. nigricans, formerly regarded as a distinct species. Populations from Yukon-Kuskokwim Delta, North Slope of Alaska, Anderson River (NWT), and Victoria Island are genetically homogeneous; Melville Island population is distinctive, apparently long isolated from other breeding populations (Shields, 1990).

The breeding range encompasses arctic North America and eastern Russia. In winter, brant occur along the Pacific coast from Alaska to Baja California and mainland Mexico, along the Atlantic coast from Massachusetts to North Carolina (mainly New Jersey to North Carolina), and from the British Isles to the Mediterranean area and south to coastal China.

BREEDS: arctic North America and Russia: Prince Patrick and Melville islands in the western Canadian high arctic and the Beaufort Sea islands to the coastal plain of Canada and Alaska, with small colonies on the north side of the Chukotka Peninsula in Russia and on Wrangel Island (Derksen and Ward 1993). In western North America, about 80% of the total black brant population nests in four major colonies on the Yukon-Kuskokwim delta in western Alaska (Derkson and Ward 1993). WINTERS: in North America, along the Pacific coast from Alaska to Baja California and mainland Mexico, along Atlantic from Massachusetts to North Carolina (mainly New Jersey to North Carolina); from British Isles to Mediterranean area, south to coastal China; occasional in Hawaii. A major shift in the winter distribution in western North America occurred during the 1950s and 1960s, with increased numbers using lagoons along the Mexican mainland and much decreased numbers wintering in California; since the mid-1960s, more than 80% of the counted winter population has occurred in Mexico (Derksen and Ward 1993). In the 1980s, an average of several thousand wintered in the Izembek Lagoon area of the Alaska Peninsula (Derksen and Ward 1993). Kasegaluk Lagoon on the Chukchi Sea in northwestern Alaska is an important migration stop during southward migration; as much as 49% of the entire Pacific flyway population may use the lagoon (Johnson 1993). Izembek Lagoon on the Alaska Peninsula is a critically important stop in spring and late summer, hosting at least the majority of the eastern Pacific population (Johnson and Herter 1989); nearly the entire black brant population spends as long as nine weeks there before departing for wintering areas to the south (Derksen and Ward 1993). Important summer molting areas occur on Alaska's north slope and Wrangel Island (Derksen and Ward 1993).

Spring subsistence harvest in western Alaska coupled with fox predation on reduced Yukon-Kuskokwim delta populations have limited the recovery of key nesting colonies in western North America (Derksen and Ward 1993). Declines in eelgrass may affect habitat use, bird condition, and reproductive success (Wilson and Atkinson 1995). Declines in British Columbia and Pacific states are due to degradation and loss of important staging and winter estuarine habitats caused by commercial and recreational development and disturbance (Derksen and Ward 1993). In Mexico, industrial and recreational development in several estuaries may further limit winter habitat (Derksen and Ward 1993).
Disturbance by humans also is a threat to birds wintering in Mexico (Derksen and Ward 1993). Habitats in Alaska, Russia, and northern Canada presently are relatively secure (Derksen and Ward 1993). Molting individuals are susceptible to disturbance by aircraft (see Taylor 1995, Auk 112:904-919).