- Histrionicus histrionicus
Length: 38â€“51 cm (15-20 in). Weight: 540-680 g.
A medium-sized diving duck. White ear patch.
 Adult male
- Slate blue with chestnut sides
- White markings including a white crescent at the base of the bill
 Adult female
- Less colourful
- Brownish-grey plumage
- White patch on the head around the eye
 Similar species
Adult male unmistakeable. Females and juveniles can be confused with female scoters at long range, particularly Surf Scoter.
Northern Atlantic and Pacific coasts and adjacent mountain rivers. North America, Greenland, Iceland and eastern Russia.
The only species in the genus Histrionicus, but fairly closely related to Long-tailed Duck and the scoters.
Two subspecies are accepted by some authors, though others consider the species monotypic.
Some eastern European vagrants are thought to come from the Pacific population, rather than the more sedentary Atlantic population.
Breeds beside cold, fast-flowing rivers; winters at sea off exposed rocky shores.
The nest is usually located in a well-concealed location on the ground near a stream.
Their diet consists mostly of molluscs and other crustaceans with the addition of insects and their larvae in the spring and summer months.
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2016. The eBird/Clements checklist of birds of the world: v2016, with updates to August 2016. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- Gill, F and D Donsker (Eds). 2014. IOC World Bird Names (version 4.4). Available at http://www.worldbirdnames.org/.
- Del Hoyo, J, A Elliot, and J Sargatal, eds. 1992. Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Barcelona: Lynx Edicions. ISBN 978-8487334108
- Madge, S. & Burn, H. (1988). Wildfowl. Helm.
- Handbook of the Birds of the World Alive (retrieved March 2017)
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