Information contained in Tables 11-15 can be summarized to show characteristics of seabird trophic relations. One such characteristic is the range of diet breadth or diet complexity (Table 16). Few species (about 6%) feed on only one type of prey and might, therefore, be referred to as "specialists." Included are eared grebe _(Podiceps caspicus)_, Laysan albatross, brown pelican, emperor goose _(Philacte canagica)_, black brant _(Bernicia bernicla)_, peregrine falcon, and whiskered auklet _(Aethia pygmaea)_. Consideration of these species as specialists may require revision when more data become available. Except for the albatross and auklet, these species are members of the inshore neritic cohort. Food specialization does not seem to be characteristic of oceanic birds in particular or of most seabirds in general.
Table 13. _Use of food resources by seabirds in the Alaska Stream domain._ Information is from Tables 1-10. (Trophic level I = plants, II = secondary carnivore, III = tertiary carnivore, IV = upper level carnivore, Sc = scavenger on carrion, offal, or detritus [II-IV]; x = major food in diet, o = minor food, * = incidental food, ? = probable food.)
---------------------------------------------------------------------------- Habitat, bird trophic levels (I-IV. Sc), and food categories
Key: Oceanic and offshore neritic II A: Crustacean B: Polychaete C: Coelenterate D: Fish/squid eggs & larvae
Inshore neritic II J: Crustacean, midwater K: Crustacean, benthic L: Coelenterate M: Echinoderm IV: N: Mollusc Sc: Q: Fish/squid eggs & larvae
III R: Fish, midwater S: Fish, benthic T: Cephalopod
Seabirds A B C D E F G H I J K L M N Q R S T U V ---------------------------------------------------------------------------- _Gavia immer_ * x x _G. adamsii_ * o x _G. stellata_ * o x _Podiceps grisegena_ o x o _Diomedea nigripes_ x o o o x x x _Fulmarus glacialis_ x o x o x x x _Puffinus griseus_ x x x o _P. tenuirostris_ x o x o _Pterodroma inexpectata_ x x _Oceanodroma furcata_ x o o x x x x _Phalacrocorax auritus_ o x o _P. pelagicus_ x x _P. urile_ x x _Philacte canagica_ x _Clangula hyemalis_ o x o _Histrionicus histrionicus_ x x o _Polysticta stelleri_ o x o o _Somateria mollissima_ x o x _S. spectabilis_ o o x _S. fischeri_ x x _Melanitta deglandi_ x o _M. perspicillata_ o x o _M. nigra_ o o x _Mergus serrator_ o x x _Haliaeetus leucocephalus_ x x x _Falco peregrinus_ x _Phalaropus fulicarius_ x x o x x _Lobipes lobatus_ x x o x x _Stercorarius_ spp. o x x ? x x x x _Larus hyperboreus_ o o o o o o o o o o x x x _L. glaucescens_ o o o o o o o o o o x x x _L. argentatus_ o o o o o o o o o o x o x _L. canus_ x o o o x x _Rissa tridactyla_ x x x o _R. brevirostris_ x x x o _Sterna paradisaea_ x x o o x o _S. aleutica_ x o _Uria aalge_ x o x x o o x o _U. lomvia_ x o x x o x o x _Lunda cirrhata_ ? x x _Fratercula corniculata_ * x x _Cepphus columba_ o x o _Brachyramphus marmoratus_ x o x _B. brevirostris_ x o _Synthliboramphus antiquus_ x x x _Cyclorrhynchus psittaculus_ x o * * _Aethia cristatella_ x x _A. pusilla_ x o _A. pygmaea_ x