Aves | Charadriiformes
Environment: milieu / climate zone / depth range / distribution range
Others; depth range 0 - 60 m (Ref. 62269). Temperate; 62°N - 28°N, 119°E - 115°W
Northern, Western and Eastern Pacific Ocean. Boreal to subtropical.
Length at first maturity / Size / Weight / Age
Maturity: Lm ?  range ? - ? cm Max length : 38.0 cm TL male/unsexed; (Ref. 8812); max. published weight: 520.00 g (Ref. 356)
Culmen: 3.45 cm; tarsus: 3.0 cm; wing: 15.24 cm.
Total Length: 35 to 38 cm (Ref. 8812). Pursuit diver; coastal; <50 km (Ref. 356). On the Farallon Islands, this species usurps nests of smaller Cassin's Auklet by destroying eggs or chicks thereby effectively lowering its habitat competitor's reproductive success. Nest site prospecting at night. Diurnal, particularly where Auklets nest in caves, but completely nocturnal where Bald Eagle colonies are present. Based on stable isotope analysis (SIA) diet study of egg albumin, belongs to higher N signature group (based on ratios of stable isotopes of nitrogen and carbon): piscivorous (Ref. 87784).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Watanuki, Y. 1987. (Ref. 4542)
IUCN Red List Status (Ref. 126983)
CITES status (Ref. 108899)
Threat to humans
| FishSource |
Estimates based on models
High, minimum population doubling time less than 15 months (K=9.33-35.4).
): 6.1 - 17.6, mean 9.7 (based on 690 cells).
Low to moderate vulnerability (28 of 100).