Range. - North Atlantic coast, more northerly than the preceding, breeding from Labrador to northern Greenland.
The bird differs from the Black Guillemot only in having the bases of the coverts white also. The nesting habits and eggs are identical. They nest in colonies of thousands and place the eggs upon the bare rock with no attempt at nest building. Generally the eggs are in the crevices so as to be difficult to get at. Size 2.30 x 1.55. Data. - Depot Island, Hudson Bay, June 6, 1894. Two eggs laid on bare rocky ground. Collector John Comer.
Xantus Murrelet. Mandt's Guillemot.