Aves | Charadriiformes
Environment: milieu / climate zone / depth range / distribution range
Others; depth range 0 - 36 m (Ref. 61831). Polar; 62°N - 34°N, 171°E - 120°W (Ref. 125423)
Pacific Ocean: California to the Aleutian Islands. Boreal to subtropical.
Length at first maturity / Size / Weight / Age
Maturity: Lm ?  range ? - ? cm Max length : 25.0 cm TL male/unsexed; (Ref. 8812); max. published weight: 202.50 g (Ref. 356)
Culmen: 1.6 cm; tarsus: 1.59 cm; wing: 12.7 cm.
An endangered species. Nesting habitat protected under ESA in the U.S. (Ref. 87784). Total Length: 24 to 25 cm (Ref. 8812). Coastal; can be found offshore up to 300 km; thermal fronts, water <30 m deep; glacial-affected. Pursuit divers (Ref. 356). Crepuscular to nocturnal. Mate prospecting thru display and calls; nocturnal vocal displays minimal. Direct or indirect intra- and interspecific competition for nest sites. Nests in trees (Ref. 87784). Breeding pairs maintain isolation from colony until the eggs are laid (Ref. 95051). Feeds on hatchery-released pink salmon and chum salmon in Prince William Sound, Alaska. Population decline associated with mortality in fishing nets (Ref. 87784).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Reproductive productivity of the species in Salish Sea declined by at most 50% over the past 150 years (Ref. 95036).
Hirsch, K.V., D.A. Woodby and L.B. Astheimer. 1981. (Ref. 8541)
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=60.76).
): 5.6 - 13, mean 8.5 (based on 451 cells).
Low vulnerability (15 of 100).