1 34 NORTH AMERICAN FAUNA 76 



Breeding birds in coastal areas show a different distribution of 

 zoogeographical affinities than those nesting inland (Table 9). Of 37 spe- 

 cies that breed only in coastal areas, 51.4% are Beringian (e.g., common 

 murre, Aleutian tern, tufted puffin), whereas most of the 59 species 

 nesting only inland are of North American affinity (e.g., gray-cheeked 

 thrush, northern waterthrush, American tree sparrow). 



As along the Alaska Peninsula (Gill et al. 1981), the Beringian group 

 accounts for a high biomass and number of avian forms migrating through 

 nearshore and littoral habitats (e.g., emperor goose, brant, common 

 eider, rock sandpiper, western sandpiper). In addition, several avian 

 forms in the Panboreal and North American groups account for large 

 numbers and high biomass during migration (e.g., king eider, surf scoter, 

 white-winged scoter). The preponderance of forms migrating along the 

 coast, however, are of the Beringian group. 



Of the 185 species found in our study area, 140 (76%) nested or 

 probably nested there. A similar proportion of species was found breed- 

 ing (82% of 62; Williamson 1957) to the north and west near Napaskiak, 

 and to the east near Iliamna Lake (78% of 103; Williamson and Peyton 

 1962). However, both those studies were conducted at more inland 

 locations either from May to June or in May, June, and August, and as a 

 result, probably excluded many migrants and winter visitants; thus, they 

 were biased toward locally breeding species. A study more comparable 

 to ours, which included spring, summer, fall, and winter observations at 

 both littoral and inland locations, was conducted by Gill et al. (1981) on 

 the north-central Alaska Peninsula. They found only 49% (6I of 125) 

 breeding or probably breeding species, a proportion much lower than 

 the 76% found by our study. We conclude that the relatively high 

 proportion of nesting or probably nesting species on our study area 

 reflects a wider diversity of habitats. 



Table 9- Zoogeographic affinity of species or presumed subspecies 

 breeding or probably breeding on the study area. 



Number of species or 

 subspecies breeding 



Beringian 



Panboreal North American 



Old World 





Ahklun or Kilbuck mountains 







(TV- 60) 



5 



4 



50 







8.3% 



6.7% 



83.3% 



1.7% 







Coastal area only 







(/V-38) 



20 



9 



8 



1 





52.6% 



23.7% 



21.0% 



2.6% 





Mountain and coastal areas 







{N-A2) 



8 



11 



23 



0 





19.0% 



26.2% 



54.8% 



0.0% 



