Which bird is it?

Crested Auklet
Aethia cristatella

This auklet is largely confined to the Bering Sea region, where it typically nests in huge colonies on islands near cold, saline water currents. Colonies of 250,000 or more of the species occur on some of the Aleutian Islands, and 28,000 Crested Auklets nest on St. George Island in the Pribilofs.

Nesting is in rocky talus slopes, where cobble and boulders provide a labyrinth of cracks and crevices in which to lay eggs. Several species of auklets frequently nest together in mixed colonies. A single egg is laid in a bare cavity in the talus.

Crested Auklets forage at ocean depths, perhaps to 40 meters (130 feet), on small, abundant, planktonic crustaceans, especially euphausiids, amphipods, and copepods. The adults carry food for the chicks back to the talus slopes in special gular (throat) pouches.