Least Auklet (aethia pusilla)

Least Auklet

[order] CHARADRIIFORMES | [family] Alcidae | [latin] aethia pusilla | [UK] Least Auklet | [FR] Starique minuscule | [DE] Zwergalk | [ES] Mergulo Minimo | [NL] Dwergalk


Monotypic species

Physical charateristics

The tiniest auk; chubby, neckless. Black above, white below. In summer, a wide dark band across the upper breast. The tiny size and very stubby bill separate it from other wintering alcids of the Aleutians.

Listen to the sound of Least Auklet

[audio:http://www.aviflevoland.nl/sounddb/L/Least Auklet.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 27 cm wingspan max.: 33 cm
size min.: 15 cm size max.: 17 cm
incubation min.: 28 days incubation max.: 32 days
fledging min.: 28 days fledging max.: 32 days
broods: 1   eggs min.: 1  
      eggs max.: 1  


Eurasia, North America : North Pacific coasts


Ocean, northern islands. May forage close to shore or far
out at sea. Favors areas with turbulent water, upwellings, strong gradients of water temperature or salinity, edges of currents, or rip currents. Nests on islands in boulder fields, talus slopes, lava flows, rock crevices.


First breeds at age of 3 years. In courtship, male perches upright and makes chattering calls; female approaches in exaggerated stretching and crouching postures, then both birds engage in bill-touching and chattering in duet. Pair-bond often lasts more t
han one season.
Nest: In colonies located in talus slopes, rock piles, other areas with abundant small rock crevices for nest sites. No nest built; egg laid on bare rock, soil, or pebbles. Pair may reuse nest site for several years.
Eggs: 1. White, becoming nest-stained. Incubation is by both sexes, 25-39 days, usually about 30 days.
Young: Both parents feed young, bringing food in throat pouch. Young develops faster than young of most auks, leaves nest 25-33 days after hatching.

Feeding habits

Crustaceans and other marine invertebrates.
Diet in summer is small creatures that occur in swarms in cold waters, mostly very small crustaceans known as calanoid copepods, also some euphausiid shrimp, amphipods, others. Diet at other seasons not well known.
Behavior: Forages by diving from surface, using wings to “fly” underwater. Fast and agile underwater but probably not able to dive very deep.


This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Least Auklet status Least Concern


Breeds in swarms on islands of Bering Sea south to Aleutians and Shumagins. Winters from Aleutians to northern Japan. Migration: Birds
from northernmost colonies move south to evade the solid ice that surrounds their colony sites in winter. Those from Pribilof and Aleutian islands may be permanent residents near colonies. Very rare stray as far south as Washington.

Distribution map

Least Auklet distribution range map

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