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.
♦ ²A COMPARISON OF THE BREEDING AND FEEDING ECOLOGY OF PIGEON GUILLEMOTS AT NAKED AND JACKPOT ISLANDS IN PRINCE WILLIAM SOUND, D. Lindsey Hayes, APEX: 95163 F. U.S. Fish and Wildlife Service, Anchorage, AK. (1996)