The Red-faced Cormorant may be the least known of all North American species. It breeds in a narrow, latitudinally compressed band from the northern Sea of Japan, along the Kuril and Aleutian Island chain, and far east into the southeastern Gulf of Alaska. Possibly owing to its shy habits and inaccessible colony sites, it is one of the least studied and least known birds of the North Pacific: Little is known beyond distribution and rudiments of ecology.
This species is similar in appearance to the Pelagic Cormorant (Phalacrocorax pelagicus), and in regions where both are seen together, the two are often confused. Many of the scientific and popular accounts of Red-faced Cormorants are based on observations of mixed groups of Pelagic and Red-faced cormorants, further limiting our understanding of the latter's natural history. The Red-faced Cormorant's range in North American waters extends throughout the Aleutian Islands, Pribilof Islands, and a few sites in the Gulf of Alaska and Norton Sound. Colonies are generally small and dispersed; only a few are large, but those are very remote from human contact. It is the least gregarious or social of all cormorants, nesting on steep, inaccessible cliff faces, and is shy of human approach.
The Red-faced Cormorant is exclusively marine and ventures onto land only to breed or roost, never intruding more than a few meters from the edge of the sea. It sometimes is observed flying far out to sea, but is more commonly associated with the inshore and coastal waters of islands and continental shelves. This species prefers solitary fish and invertebrates near the bottom and feeds by underwater pursuit of its prey. Morphology, behavior, and genetics place it as a member of the subfamily Leucocarboninae (see Systematics, below), and it is closely allied with other cliff-nest-ing cormorants found throughout the world. The name "shag," often applied to this group of cormorants, is used at times in this account.
The behavioral repertoire of the Red-faced Cormorant is similar to that of Pelagic Cormorant, and is particularly prominent during the breeding season. Like all cormorants, this species is easily disturbed on the colony and is particularly vulnerable to petroleum spills, chemical and plastic contamination, and nearshore fishing activities. Most aspects of its ecology, breeding biology, population dynamics, and even the basic natural history of this species remain unstudied. Ongoing monitoring studies by the U.S. Fish and Wildlife Service in the Aleutian Islands, however, continue to provide valuable data on Red-faced Cormorant numbers, movements, and rudiments of its reproductive ecology ( Byrd et al. 1985b , Byrd and Hector 1989 , Byrd and Hector 1989 , Climo 1993 , Meehan et al. 1996 , Byrd and Dragoo 1997 ).