Ice-dependent species tied to arctic pack ice. Concentrate at ice edges to feed (Butler and Buckley 2002). Nests in crevices on rocky sea cliffs or in cavities found on rocky shorelines or headlands. In northern Alaska, where there are low coastal tundra bluffs, the species nests in driftwood piles and manmade structures. They require at least 80 snow-free days from egg laying to fledglings leaving the nest.
Butler, R. G. and D. E. Buckley. 2002. Black Guillemot (Cepphus grylle). In The Birds of North America, No. 675 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.