Burger 



Chapter 29 



Marine Distribution. Abundance, Habitats in British Columbia 



Shoreline surveys in 1976 and 1977 by Vermeer and 

 others (1983) show similar trends: low densities were found 

 in October and November in most areas in the Queen 

 Charlotte Islands and nearshore waters of the Strait of 

 Georgia (table 1). Robertson (1974) reported higher densities 

 of Marbled Murrelets in protected waters off southwest 

 Vancouver Island in summer (11.19 km 2 ) and found low 

 densities in sheltered inlets during winter (range 0.1 3-1. 177 

 km 2 ). More recently, high densities were found among 

 islands on the northern edge of the Strait of Georgia 

 (Harfenist. pers. comm.) and at some inlets off the strait 

 (Burns, pers. comm.; Prestash, pers. comm.). 



Year-round surveys have been made at few sites. Those 

 in Barkley Sound and adjacent waters show that murrelet 

 densities rise in April and decline in late July and August 

 (fig. 2). Some of these birds appear to move into Alberni 

 Canal in winter, but the relatively low densities there cannot 

 account for all the Barkley Sound murrelets. In the Strait of 

 Georgia, murrelets were more common between Sidney and 

 Mandarte Island between May and October than in winter, 

 whereas densities were higher in winter in the sheltered 

 fjords of Jervis and Saanich Inlets (fig. 3) and also in Puget 

 Sound in Washington (Speich and others 1992; Speich and 

 Wahl, this volume). The winter counts might include birds 

 from exposed western and northern parts of British Columbia. 



There is no evidence of a major move into pelagic 

 waters in fall or winter (Burger, unpubl. data; Morgan and 

 others 1991; Vermeer and others 1983, 1989b). Low to 

 moderate densities (0.01 to 1 .00 birds per km) were reported 

 from only two areas of open water in winter (in central 

 Hecate Strait, between the Queen Charlotte Islands and Banks 

 Island, and over La Perouse Bank off S W Vancouver Island) 

 (Morgan and others 1991). 



Overall, it seems that selected parts of the Strait of Georgia 

 and Puget Sound are the primary wintering areas of murrelets 

 breeding in British Columbia. Small numbers overwinter in 

 most of the coastal waters and more open ocean. Winter 

 samples are, however, very inadequate and other important 

 wintering areas will undoubtedly be discovered. 



Habitats Used 



Coarse-Scale Comparisons 



Marbled Murrelets in British Columbia tend to aggregate 

 within 500 m of land on exposed shores and within 1-5 km in 

 more sheltered waters (Morgan and others 1991; Sealy and 

 Carter 1984; Vermeer and others 1983, 1987). They are 

 relatively rare in more open pelagic water or in the centers of 

 broad straits; consequently these waters were not considered 

 in the following analysis. 



Table 1 Seasonal changes in densities of Marbled Murrelets recorded during boat surveys in 1976 and 

 1977 (Vermeer and others 1983) 



USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 



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