Least Auklet

Aethia pusilla

Smallest auk in the world, smaller than a sparrow. Nests in colonies of a million in Aleutian rockslides.

Population: Roughly 9 million+ birds range-wide (Wikipedia/Cornell-derived figure) vs. BirdLife/IUCN DataZone ~20 million mature individuals (2013 est.); one of the most abundant seabirds in the North Pacific, decreasing trend
Habitat: Pelagic ocean waters outside the breeding season (subtidal zones, rock reefs, seagrass beds, high-plankton-density pelagic waters); breeds colonially on rocky islands and sea cliffs, nesting in crevices among talus slopes and boulder/rock rubble, sometimes coastal cliff crevices and tidepool margins
Fun fact: The Least Auklet is the smallest member of the auk family - barely larger than a sparrow - yet it forms some of the densest seabird colonies on Earth, with millions nesting together in rock crevices on Bering Sea islands.
Range: North Pacific: breeds on islands and coasts of the Bering Sea and Chukchi Sea region, including the Aleutian Islands, St. Lawrence Island, Little Diomede, and Siberian coasts (breeding extent of occurrence ~4,510,000 km² per BirdLife); winters at sea near pack-ice edges from Japan/southwestern Alaska north to the southern Chukchi Sea, occasionally straying south to British Columbia/Washington
Diet: Zooplankton, mainly calanoid copepods (especially Neocalanus), plus euphausiid shrimp, pteropods, amphipods, and other small crustaceans caught by pursuit-diving; consumes roughly 80%+ of body weight daily
Size: 0.15 m
Wingspan: 0.34 m
Lifespan: 13 years

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