I examined diet and foraging habitat selection by Black Guillemots (Cepphus grylle) in the eastern Canadian arctic. Birds fed on fish (Boreogadus saida, Stichaeus punctatus, Eumesogrammus praecisus) and mysid, amphipod, and decapod crustaceans. Guillemots concentrated at landfast ice edges early in the breeding season. Open-water foraging occurred principally in waters 10–30 m deep within 13 km of breeding colonies. Guillemots were aggregated on the water, but their distributions were not correlated with those of schooling prey. Guillemots feeding in open water obtained much of their food on the bottom, but some prey was likely taken during transit to and from the bottom.
Kleptoparasitic interactions of Arctic Skuas Stercorarius parasiticus and Black Guillemots Cepphus grylle in northeastern Hudson Bay, Canada
