Attributes / relations provided by
♦ ¹del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.
♦ ²An estimate of summer food consumption of six seabird species in Iceland, K. Lilliendahl and J. Solmundsson, ICES Journal of Marine Science, 54: 624–630. 1997
♦ ³Seasonal and geographical variations in the diet of Common Guillemots Uria aalge off western Scotland, D J Halley, N. Harrison, A. Webb and D.R. Thompson, SEABIRD 17: 12-20
♦ ⁴Food Web Relationships of Northern Puget Sound and the Strait of Juan de Fuca : a Synthesis of the Available Knowledge, Charles A. Simenstad, Bruce S. Miller, Carl F. Nyblade, Kathleen Thornburgh, and Lewis J. Bledsoe, EPA-600 7-29-259 September 1979