Synthliboramphus antiquus

Constitutes a superspecies with S. SUMIZUSUME of Japan (AOU 1998).

Still widespread and abundant, but concentrated for the most part in only a handful of large colonies. Numbers have declined substantially in the past century; some of the largest remaining colonies have declined rapidly in the past few decades, and many are still threatened with extirpation by introduced rats, raccoons, and foxes.

Breeding range includes the following regions: Aleutian, Sanak, and Kodiak islands to Haida Gwaii ( Queen Charlotte Islands), and Commander Islands and Kamchatka (Peninskaya Gulf) to Amurland, Sakhalin, Kuriles, Korea, and Dagelet Islands (to Yellow Sea coast of China). This species is sparsely distributed in small colonies on the Asian side of the Pacific and is most abundant in Haida Gwaii ( Queen Charlotte Islands) and adjacent parts of southeastern Alaska; it is also abundant at Sandman Reefs and other islands south of the Alaska Peninsula (Gaston 1992). Outside the breeding season the distribution extends well to the south of the breeding range; in North America, this murrelet occurs offshore from the Pribilof Islands to northern Baja California (AOU 1983).

There are 30+ nesting areas along the coast of the northwestern Pacific Ocean; about 75 in Alaska, and 31 in British Columbia (Gaston 1993, Gaston 1994). More than half the breeding population is concentrated in 12 colonies off Haida Gwaii ( Queen Charlotte Islands), British Columbia.

Declines in Haida Gwaii (Queen Charlotte Islands) have been attributed to predation by raccoons and introduced rats, and reductions in food availability due to pesticide pollution or changes in marine current systems controlling local productivity (see Gaston 1992). Overall, probably introduced predators have been the dominant factor in determining population trends in Alaska and British Columbia (Gaston 1992, 1994). Some colonies are in danger of extirpation due to rat predation; the raccoon population in Haida Gwaii (Queen Charlotte Islands) is spreading and threatening many seabird colonies (Gaston 1993, 1994). Some British Columbia colonies are threatened by logging of mature trees; these also may be vulnerable to oil spills on staging and feeding areas (Vermeer and Sealy 1984). Introduced foxes are a threat in some areas (e.g., on Alaskan islands) (Lensink 1984, Bailey 1993).

This species is "Very sensitive to disturbance during incubation, when any intrusion usually leads to desertion. On dark nights many birds attracted to bright lights" (Gaston 1994).