Storm-petrels are especially difficult to census because they are nocturnal, and the burrows and rock crevices where they breed are often difficult to locate, especially in mixed-species colonies. The census data are inadequate to determine whether there have been changes in population density and distribution. Indeed, the biology of this species is perhaps the least known of the North Pacific colonial seabirds. In southeastern Alaska, this species is outnumbered by at least 5 to 1 by the Leach's storm-petrel (Oceanodroma leucorhoa). The reasons for this are poorly understood. There is some evidence that the numbers of breeding fork-tailed storm-petrels on Forrester Island may fluctuate drastically from one year to the next (Gabrielson and Lincoln 1959).

Leach's Storm-petrel (Oceanodroma leucorhoa)

Of the two subspecies of this petrel (O. l. leucorhoa and O. l. beali), only O. l. beali is found in southeastern Alaska. The leucorhoa subspecies is more northerly in distribution. Where both fork-tailed and Leach's storm-petrels are sympatric, Leach's predominates; however, this relationship becomes more unpredictable in British Columbia and Washington. This species is undoubtedly widespread in the forested islands of the Alexander Archipelago.

Double-crested Cormorant (Phalacrocorax auritus)

The double-crested cormorant apparently does not breed in southeastern Alaska since Willett (1912), Gabrielson and Lincoln (1959), and S. Patten (personal communication) do not report breeding colonies for the area. The largest populations occur in southern British Columbia principally in the Gulf Islands, where 71% of all breeding double-crested cormorants are found (Table 10). According to Jewett et al. (1953), this species was less common in Puget Sound than was Brandt's cormorant, but is certainly not the case today (D. A. Manuwal, unpublished data). The only common cormorants in the San Juan Islands are the pelagic and double-crested species. The double-crested cormorant seems to have declined in numbers on both coastal and inland waters. On the basis of his observations, R. W. Campbell believes that this species is increasing in British Columbia.

Table 9. Distribution and status of marine birds breeding along the Pacific coast of Washington, British Columbia, and southeastern Alaska. (X = known to breed in the region;? = data insufficient; + = evidence indicates an overall increase in size of population; - = evidence indicates an overall decrease in size of population; 0 = no population change.)
Family and speciesCommon nameWashingtonBritish ColumbiaSoutheastern Alaska
PresenceStatusPresenceStatusPresenceStatus
Hydrobatidae
Oceanodroma furcataFork-tailed storm-petrelX?X?X?
O. leucorhoaLeach's storm-petrelX?X-X?
Phalacrocoracidae
Phalacrocorax auritusDouble-crested cormorantX-X-
P. penicillatusBrandt's cormorantX?X0?
P. pelagicusPelagic cormorantX?X+X?
Haematopodidae
Haematopus bachmaniBlack oystercatcherX?X+X?
Laridae
Larus glaucescensGlaucous-winged gullX+X+X?
L. occidentalisWestern gullX?X?
L. argentatusHerring gullX?
Rissa tridactylaBlack-legged kittiwakeX?
Alcidae
Uria aalgeCommon murreX?X-X?
Cepphus columbaPigeon guillemotX?X+X?
Brachyramphus marmoratusMarbled murreletX?X?X?
B. brevirostrisKittlitz's murreletX?
Synthliboramphus antiquusAncient murreletX?X?
Ptychoramphus aleuticusCassin's aukletX?X?X-
Cerorhinca monocerataRhinoceros aukletX?X+X?
Fratercula corniculataHorned puffinX?
Lunda cirrhataTufted puffinX-X0X?
Total species141516
Brandt's Cormorant (Phalacrocorax penicillatus)

Brandt's cormorant is the least abundant of the three cormorant species that nest in the study area. Washington is at the northernmost edge of the breeding distribution of this species. Only one more northerly colony exists, on Sartine Island off Vancouver Island (Vermeer et al. 1976). Brandt's cormorant comprises about 85% of the cormorant population in Oregon (U.S. Fish and Wildlife Service, unpublished data). However, in Washington it is only about 9% and in British Columbia 3% of the total cormorant population.