Animalia > Chordata > Aves > Charadriiformes > Alcidae > Aethia > Aethia pusilla

Aethia pusilla (Least Auklet)

Wikipedia Abstract

The least auklet (Aethia pusilla) is a seabird and the smallest species of auk. It is the most abundant seabird in North America, and one of the most abundant in the world, with a population of around nine million birds. They breed on the islands of Alaska and Siberia, and spend the winter close to the edge of the ice sheet. Their largest colonies are on the Aleutian Islands, St. Lawrence Island and Little Diomede Island.
View Wikipedia Record: Aethia pusilla

EDGE Analysis

Uniqueness Scale: Similiar (0) 
 Unique (100)
Uniqueness & Vulnerability Scale: Similiar & Secure (0) 
 Unique & Vulnerable (100)
ED Score: 6.74213
EDGE Score: 2.04668


Adult Weight [1]  96 grams
Birth Weight [3]  17.4 grams
Female Maturity [1]  3 years
Male Maturity [1]  3 years
Breeding Habitat [2]  Coastal cliffs and islands, Coastal marine
Wintering Geography [2]  Pacific Coast
Wintering Habitat [2]  Coastal marine
Diet [4]  Carnivore (Invertebrates)
Diet - Invertibrates [4]  100 %
Forages - Underwater [4]  100 %
Clutch Size [1]  1
Clutches / Year [1]  1
Global Population (2017 est.) [2]  20,000,000
Incubation [1]  30 days
Maximum Longevity [1]  8 years
Migration [5]  Intercontinental
Wing Span [6]  13 inches (.325 m)


Name Countries Ecozone Biome Species Report Climate Land
Chukchi Peninsula tundra Russia Palearctic Tundra

Protected Areas

Name IUCN Category Area acres Location Species Website Climate Land Use
Alaska Maritime National Wildlife Refuge Ib 2347132 Alaska, United States
Aleutian Islands Biosphere Reserve 2720489 Alaska, United States    
Kronotskiy Biosphere Reserve 361480 Russia  
Sikhote-Alinskiy Biosphere Reserve 978001 Russia  

Important Bird Areas

BirdLife Species Factsheet: View Factsheet
Name Location  IBA Criteria   Website   Climate   Land Use 
Gareloi Island USA A4ii    
Iony island Russia (Asian) A4i, A4ii, A4iii    
Kiska Island USA A4ii  
Ratmanova island Russia (Asian) A4ii, A4iii    
Segula-Davidof Islands USA A4ii    
St. Lawrence Island USA A4ii
Yamsk archipelago Russia (Asian) A4ii, A4iii    

Prey / Diet

Ammodytes americanus (inshore sand lance)[7]
Ammodytes hexapterus (Stout sand lance)[7]
Ammodytes marinus (sand eel)[7]
Boreogadus saida (Polar cod)[7]
Calanus marshallae[8]
Eleginus gracilis (Wachna cod)[7]
Eucalanus bungii[8]
Gadus chalcogrammus (Whiting)[7]
Gadus macrocephalus (Pacific cod)[7]
Gadus morhua (rock cod)[7]
Macruronus magellanicus (Patagonian whiphake)[7]
Macruronus novaezelandiae (Whiptail hake)[7]
Micromesistius australis (Southern poutassou)[7]
Micromesistius poutassou (Poutassou)[7]
Neocalanus cristatus[8]
Neocalanus plumchrus[8]
Pleurogrammus azonus (Okhotsk atka mackerel)[7]
Pleurogrammus monopterygius (Atka mackerel)[7]
Pollachius virens (Sillock)[7]
Pseudocalanus elongatus[8]
Pseudophycis bachus (Southern rockcod)[7]
ucalanus bungii[8]

Prey / Diet Overlap

Competing SpeciesCommon Prey Count
Aethia pygmaea (Whiskered Auklet)2
Balaenoptera borealis (Sei Whale)1
Balaenoptera physalus (Fin Whale)1
Diaphus theta (California headlightfish)3
Eubalaena glacialis (Northern Right Whale)1
Fulmarus glacialis (Northern Fulmar)2
Nannobrachium regale (Small-eyed lantern-fish)1
Oceanodroma furcata (Fork-tailed Storm-Petrel)1
Oncorhynchus gorbuscha (humpbacked salmon)1
Oncorhynchus keta (Calico salmon)1
Oncorhynchus nerka (sockeye salmon or kokanee)1
Protomyctophum thompsoni (Bigeye lanternfish)1
Stenobrachius leucopsarus (Smallfin lanternfish)2


Haliaeetus leucocephalus (Bald Eagle)[7]

Institutions (Zoos, etc.)

Institution Infraspecies / Breed 
Cincinnati Zoo & Botanical Garden

Range Map

North America;



Attributes / relations provided by
1de Magalhaes, J. P., and Costa, J. (2009) A database of vertebrate longevity records and their relation to other life-history traits. Journal of Evolutionary Biology 22(8):1770-1774
2Partners in Flight Avian Conservation Assessment Database, version 2017. Accessed on January 2018.
3Terje Lislevand, Jordi Figuerola, and Tamás Székely. 2007. Avian body sizes in relation to fecundity, mating system, display behavior, and resource sharing. Ecology 88:1605
4Hamish Wilman, Jonathan Belmaker, Jennifer Simpson, Carolina de la Rosa, Marcelo M. Rivadeneira, and Walter Jetz. 2014. EltonTraits 1.0: Species-level foraging attributes of the world's birds and mammals. Ecology 95:2027
5Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2006. The Animal Diversity Web (online). Accessed February 01, 2010 at
6Anatomy and Histochemistry of Flight Muscles in a Wing-Propelled Diving Bird, the Atlantic Puffin, Fratercula arctica, Christopher E. Kovacs and Ron A. Meyers, JOURNAL OF MORPHOLOGY 244:109–125 (2000)
7Jorrit H. Poelen, James D. Simons and Chris J. Mungall. (2014). Global Biotic Interactions: An open infrastructure to share and analyze species-interaction datasets. Ecological Informatics.
8Foraging habitat and prey taken by least auklets at King Island, Alaska, George L. Hunt, Jr, Nancy M. Harrison, MARINE ECOLOGY PROGRESS SERIES, Vol. 65: 141-150, 1990
Ecoregions provided by World Wide Fund For Nature (WWF). WildFinder: Online database of species distributions, ver. 01.06 WWF WildFINDER
Images provided by Google Image Search
Abstract provided by DBpedia licensed under a Creative Commons License
Weather provided by NOAA METAR Data Access