Phoebastria nigripes is the only mostly dark plumaged albatross in its range. Adults weigh around 3.2 kilograms, with males approximately 10% heavier than females. They have a wingspan of 1.8 to 2.1 meters, and are generally 68 to 74 cm in body length. As adults, both genders have similar coloration, though males are heavier and have a deeper and longer bill. Birds become progressively whiter as the age, particularly in the belly (ventral side), rump (tail coverts), and around the base of the bill. Juveniles have less prominent white plumage around the bill, and therefore appear overall darker than adults.
The simplest field identifiers for the black-footed albatross are large and high aspect-ratio wings and soaring flight. Wings are elongated—large for seabirds generally, but small compared with other albatrosses. The dark plumage and feet distinguish this species from the other two North Pacific albatrosses.
Can be Confused With
Two congeners (included in subgenus with the black-footed) are the Laysan (P. immutabilis) and short-tailed (P. albatrus) albatrosses, which both occur in the range of the black-footed albatross. They can be distinguished simply from both the Laysan and short-tailed albatrosses by their general dark color.
Black-footed albatross may be confused with the rare immature short-tailed albatross, which have a uniformly dark brown appearance. However, short-tailed albatrosses are larger in size and have pink feet and a large and pinkish “bubble-gum” bill. Black-footed albatross should be differentiated by feet and bill, and by their smaller size.
Black-footed albatrosses have a cosmopolitan distribution and breed mostly on the northwestern Hawaiian Archipelago and off Japan. They arrive at their nesting sites by the end of October, and then incubate and brood chicks from November until February. Adults continue to provision their chicks from March until June. These seabirds spend the non-breeding season in the North Pacific Ocean (30-60° latitude). Found throughout the North Pacific Ocean, from the West Coast of North America to Japan and from the tropics (southernmost range extent approximately 10° N) to the Gulf of Alaska, and into the SE Bering Sea.
Ecology and Behavior
The black-footed albatross is an open ocean species, coming to land exclusively to breed. Black-footed albatrosses live approximately 40 to 50 years, and mate for life. They become reproductively mature at 8 to 10 years old, breeding on average every 1 to 2 years. One chick is produced per breeding season.
Quiet and solitary at sea, though large flocks (hundreds of birds) occasionally form to exploit fish discards from factory trawlers. Noisy in groups at sea, with groaning or squealing noises and bill-snapping.
Feeding and Prey
Phoebastria nigripes have a broad diet dominated by fish > squid > invertebrates. They mainly feeds on flying fish (Exocoetidae) egg masses and adults, and secondarily squid (Order Teuthoidea). They will also consume crustaceans, other invertebrates and carrion.
Phoebastria nigripes feed by seizing prey at the surface or shallow surface diving, though black-footed albatrosses do not usually submerge fully. They are known to follow and otherwise aggregate at ships and to consume fisheries discards. In particular, black-footed albatrosses scavenge at pelagic gillnets and steal bait from longlines. Thus, these albatrosses often scavenge large squid and fish, as well as mammals and seabirds.
Main threats for black-footed albatrosses include entanglement in debris/fishing gear, fisheries bycatch, and oil and plastic pollution. Currently, the IUCN lists black-footed albatrosses as “Vulnerable” and are not listed under the United States Endangered Species Act.
Hunt, G.L., Jr., H. Kato and S.M. McKinnell. eds. 2000. Predation by marine birds and mammals in the subarctic North Pacific Ocean. PICES Scientific Report No. 14. North Pacific Marine Science Organization, Sidney.
Tickell, W.L.N. 2000. Albatrosses. Yale University Press, London.
Vermeer, K., K.H. Briggs and D. Siegel-Causey. eds. 1993. The status, ecology, and conservation of marine birds of the North Pacific. Special Publications Canadian Wildlife Service, Ottawa.
Whittow G.C. 1993. The Black-footed albatross (Diomedea nigripes). pp. 1-16 in A. Poole and F. Gill, eds. The Birds of North America, No. 65. The American Ornithologists’ Union, Washington, DC.