This is an adult in breeding plumage. Aleutian populations average more white in their wing. They are
also have shorter bills but longer wings cf. populations further south into coastal California. Canon PowerShot
SX50 HS.References:
Ewins, Peter J.(1993).Pigeon Guillemot (Cepphus columba), The Birds of North America (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America: https://birdsna.org/Species-Account/bna/species/piggui
Nettleship, D.N. & Boesman, P. (2017). Pigeon Guillemot (Cepphus columba). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/54064 on 6 July 2017).