SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 



75 



Table 2. Population estimates of seabirds breeding on St. Lazaria and Forrester islands, south- 

 eastern Alaska (data from Willett 1912 and 1915). 



St. Lazaria Island 



Forrester Island 



The studies by Willett (1912, 1915) and 

 Heath (1915) provide some base-line informa- 

 tion on species composition and abundance 

 with which future studies on St. Lazaria and 

 Forrester islands can be compared (Table 2). 

 The somewhat greater species diversity on 

 Forrester Island is primarily due to its 

 greater size and more suitable soil type for an- 

 cient murrelets (Synthliboramphus antiquus) 

 and Cassin's auklets (Ptychoramphus aleu- 

 tica), species that are absent on St. Lazaria. 

 Storm-petrels (Oceanodroma spp.) are the 

 most numerous species on both islands, but 

 there are proportionately more storm-petrels 

 (88%) on St. Lazaria than on Forrester (36%). 

 On the other hand, there are many large, bur- 

 rowing alcids on Forrester Island. Nearly a 

 third of the birds on Forrester are rhinoceros 

 auklets (Cerorhinca monocerata), tufted 

 puffins (Lunda cirrhata), and horned puffins 

 (Fratercula corniculata). 



The species composition of seabirds breed- 

 ing on other islands is similar to that found on 

 Forrester and St. Lazaria islands but less 

 abundant. In Glacier Bay, for example, the 

 only population data available are those pro- 

 vided by Patten (1974) for North Marble Is- 

 land: pelagic cormorants, Phalacrocorax 

 pelagicus (30 pairs); black oystercatchers, 

 Haematopus bachmani (8); herring gulls (7); 

 glaucous- winged gulls (500); common murres, 

 Uria aalge (18); pigeon guillemots, Cepphus 

 columba (60); horned puffins (4); and tufted 

 puffins (30). 



At the present time, it is impossible to draw 

 any conclusions about changes in population 

 density and distribution for most of the sea- 

 birds breeding in southeastern Alaska. Ade- 

 quate data are available only for St. Lazaria 

 and Forrester islands where Willet and Heath 

 provided the only early extensive census data 

 for this part of Alaska. 



British Columbia 



The rugged British Columbia coastline is 

 characterized by 930 km of islands and inlets 

 (Figs. 2, 3). With the exception of the inner 

 southern portion, this coast is mostly unin- 

 habited. The physical characteristics of the 

 offshore islands are similar to those found off 

 the Washington coast. Descriptions of some 

 of these islands and the 15 species of breeding 

 seabirds on them have been given by Drent 

 and Guiguet (1961), Guiguet (1971), and 

 Summers (1974). 



A detailed analysis of British Columbia sea- 

 birds is not presented here since a more 

 thorough analysis is in preparation by R. W. 

 Campbell and R. H. Drent (manuscript). In- 

 stead, we present seabird population esti- 

 mates available for the Province up to the 

 summer of 1975; Tables 3 and 4 summarize 

 these estimates for the five major portions of 

 coastal British Columbia. The coast of British 

 Columbia contains a myriad of small islands 

 where there may be small numbers of breed- 



