74 



D. A. MANUWAL AND R. W. CAMPBELL 



Table 1. Taxonomic distribution of marine birds breeding along the Pacific Coast of Washing- 

 ton, British Columbia, and southeastern Alaska. 



Regions 



Taxonomic Distribution 

 of Marine Birds 



There are 19 species of seabirds that breed 

 along the Pacific coast of southeastern 

 Alaska, British Columbia, and Washington 

 (Table 1). Southeastern Alaska has the 

 largest number (17) of species. Errors in 

 species identification are most likely with the 

 Larus gulls, particularly in southeastern 

 Alaska where the herring gull (L. argentatus) 

 and glaucous- winged gull (L. glaucescens) 

 breed in mixed colonies (Patten and Weisbrod 

 1974). A similar situation exists in Washing- 

 ton where the western (L. occidentalis) and 

 glaucous- winged gulls intergrade (Scott 

 1971). Brandt's (Phalacrocorax penicillatus) 

 and double-crested cormorants (P. auritus) 

 are often difficult to identify from the air. 

 This would be a problem in Washington and 

 the southwest coast of Vancouver Island, 

 where the two species are locally sympatric. 



Southeastern Alaska 



The area under consideration is the 400-km- 

 long Alexander Archipelago (Fig. 1). This 

 complex pattern of islands, bays, and inlets is 

 characterized by extremely high precipitation 

 and typical cool marine temperatures. Aver- 

 age annual precipitation in the Sitka area is 

 245.4 cm (1931-60), and the average annual 

 temperature is 6.3 C (U. S. Weather Bureau 

 1974). As a consequence of this cool, humid 

 environment, most of the islands are densely 

 covered with conifers, chiefly Sitka spruce 

 (Picea sitkensis) and hemlock (Tsuga hetero- 

 phylla), and an almost impenetrable shrub 



cover composed of salmonberry (Rubus 

 spectabilis), elderberry (Sambucus callicaipa), 

 devil's club (Echinopanax horridus), and three 

 species of Vaccinium (Heath 1915). 



There are 16 species of marine birds breed- 

 ing in the Alexander Archipelago. The major 

 seabird breeding colonies are located at Gla- 

 cier Bay and at St. Lazaria, Hazy, and For- 

 rester islands (Fig. 1; Table 2). Published sur- 

 veys of these colonies are available only for 

 St. Lazaria (Willett 1912) and Forrester is- 

 lands (Heath 1915; Willett 1915). Several 

 authors have reported on seabirds from sur- 

 rounding areas (Grinnell 1897, 1898, 1909; 

 Swarth 1911, 1922, 1936; Patten 1974). There 

 have been no surveys of seabirds of southeast- 

 ern Alaska since before the 1940's (J. G. King, 

 Jr., personal communication). However, since 

 census data are available for only two colo- 

 nies, we discuss them in more detail. 



PACIFIC OCEAN 



Fig. 1. Map of southeastern Alaska showing major 

 seabird breeding colonies: 1 North Marble 

 Island; 2 Forrester Island. 



