Which bird is it?

Parakeet Auklet
Cyclorrhynchus psittacula

Over 90% of the world's Parakeet Auklets occur in the Bering Sea region. Most nest in small, scattered groups or as solitary pairs, but some 150,000 birds nest on St. George Island in the Pribilofs, which is the center of abundance for this species.

The Parakeet Auklet nests in crevices in precipitous rock faces, such as rocky outcrops, fractured pinnacles, and sea cliffs. It also nests in rocky talus, where it may occur in mixed colonies with other auklets. The clutch consists of only one egg, which is laid on bare ground.
Primarily an offshore feeder, this auklet forages mostly on planktonic crustaceans, especially euphausiids, amphipods, and copepods; but on the Pribilofs it also takes larval pollock. Prey capture is by pursuit-diving, and food is carried to the nestlings in specialized gular (throat) pouches.