This species is less common in British Columbia than either Alaska or Washington. A possible reason for this is lack of suitable nesting areas. In Washington, the two largest colonies are at Protection Island in the Strait of Juan de Fuca and Destruction Island on the outer coast. Smaller numbers exist on other coastal islands and on Smith Island in the Strait of Juan de Fuca. The Smith Island colony is an interesting one since it appears that early human disturbance in the late 19th or early 20th century eliminated the species from the island. In their discussion of Smith Island, Jewett et al. (1953) made no mention of auklets, only of puffins and guillemots. Couch (1929) did not record the species in 1925. The colony now numbers about 600 pairs.
Horned Puffin (Fratercula corniculata)
Although the horned puffin is one of the most abundant seabirds in other parts of Alaska, it is much less abundant in the southeastern portion. In addition to the information discussed by Sealy (1973), it now appears that this species may breed as far south as Triangle Island, British Columbia (K. Vermeer, personal communication; D. A. Manuwal, personal observation). Here, as on Forrester Island, it is greatly outnumbered by the tufted puffin. No data are available on the breeding or status of this species in the study area.
Tufted Puffin (Lunda cirrhata)
The tufted puffin is found breeding on scattered islands throughout the region. The largest known colonies are on Forrester Island, Alaska, Triangle Island, British Columbia, and Carroll Island, Washington. It is notably absent from most of the gulf and San Juan Islands. Even though puffins have apparently never been numerous in the San Juan Islands, their population has noticeably declined during the past 35 years. For example, Jewett et al. (1953) reported a colony of 50 pairs on Bare Island in 1937, but in 1973 only 2 pairs were counted (D. A. Manuwal, unpublished data). Likewise, in 1915 there were more than 250 pairs on Smith Island, but by 1916 there were only 75 pairs (Jewett et al. 1953). The decline is attributed to rapid erosion of the glacial-deposit cliffs. There are no puffins on Smith Island today, and the largest colony in the Puget Sound area is the 35 pairs on Protection Island (D. A. Manuwal, unpublished data).
Discussion
The total minimum estimate of the breeding seabird populations of British Columbia and Washington is 216,500 pairs (Table 10). No comprehensive estimates are available for breeding seabirds of southeastern Alaska. It is likely, however, that the number of breeding seabirds in the Alexander Archipelago may be equal to (or exceed) the populations of both British Columbia and Washington. Data are desperately needed from that area. Of the total seabird population in the study area (Table 10) 43% reside in northern British Columbia. The Washington State population represents 28% of the total. Fork-tailed storm-petrels comprise almost 25% of all the breeding seabirds in the area under consideration. The Cassin's auklet is the next most numerous species (18% of the total).
It is apparent that current data are, for the most part, inadequate for assessing anything but catastrophic changes in seabird breeding colonies. This inadequacy is due to inadequate censusing because of excessive reliance upon aerial surveys; in the past, this has often been a result of insufficient funding.
Of the several threats facing seabird populations, none may be as important as oil pollution. A general review of this subject is presented elsewhere by Vermeer and Vermeer (1975). It is apparent from this review that the most vulnerable species are those that dive beneath the sea surface, including all the alcids and cormorants breeding along the coast that are discussed in this paper. This group makes up almost 60% of all the breeding seabirds in this area. Unfortunately, our knowledge of several of these species is scanty and our current census techniques are unsuitable for most of these birds.
Studies of the changes in seabird numbers have been made in other oceans. For example, in Great Britain (Bourne 1972a, 1972b; Harris 1970), eastern Canada (Nettleship 1973), and the Atlantic coast of the United States (Kadlec and Drury 1968), two major trends seem apparent. First, there is an overall decline in alcid and tern numbers. The decline in auks may be due to their extreme vulnerability to oil pollution (Bourne 1972a, 1972b; Vermeer and Vermeer 1975). The Atlantic puffin, however, may be suffering the additional effects of gull cleptoparasitism (Nettleship 1972). Secondly, there seems to be an increase in gull populations on both sides of the Atlantic, particularly the herring gull and black-legged kittiwake.