Burger 



Chapter 29 Marine Distribution, Abundance, Habitats in British Columbia 



Prince Rupert 



BRITISH COLUMBIA 



Density of Marbled Murrelets 

 in marine surveys 

 (birds per km) 

 e 

 0.01 - 1 

 1-5 

 A 5-10 

 10-15 



scale 



50 



km 



100 



Vancouver 



Figure 4 Mean estimates of the densities of Marbled Murrelets during the breeding season (May through July) 

 from marine surveys in British Columbia. The data are shown as birds per km of transect, which was the most 

 compatible measure among the variable studies (see appendix 1 for details) . Most of these data were collected 

 in the 1980s and early 1990s. 



Fine-Scale Comparisons 



Habitats 



Several studies reported murrelet habitat use on a finer 

 spatial scale (0.1-1.0 km). In deep fjords, higher densities 

 were associated with estuaries, shallow bays, and waters off 

 beaches (Morgan 1989, Vermeer 1989, Vermeer and Morgan 

 1992). This might be linked with the habitat supporting prey 

 species such as sand lance (Ammodytes hexapterus), which 

 bury themselves in sand for parts of the day (Field 1988). 



Off NW Vancouver Island, murrelets avoided deep open 

 water in fjords, but in shallower, sheltered bays and exposed 

 nearshore seas densities were higher in open water (5.587 

 km) than in inlets (0.16/km) or channels (0.56/km; Savard 

 and Lemon 1992). 



Sealy and Carter (1984) reviewed the distribution of 

 9955 sightings of murrelets in a grid census of Barkley and 

 Clayoquot Sounds. Murrelet densities were highest in inshore 



300 



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



