Steller's Eider
Polysticta stelleri
小绒鸭
Introduction
A migratory Arctic sea duck and the smallest and fastest-flying of the eider species. It is closely related to other eider species in the genus Somateria but is sufficiently distinct to be classified as the only member of the genus Polysticta. The species breeds along the coastlines of Russia and Alaska, as well as in the Baltic Sea. Due to the extensive contraction of its breeding range, the Alaska-breeding population was listed as vulnerable by the IUCN in 1997. The species is protected in Estonia, Finland, Norway, Russia, and the United States, and is subject to ongoing recovery plans by the European Union and U.S. Fish and Wildlife Service.
Description
The smallest of the four eider species, with both sexes averaging 860 g (30 oz). It has a compact body, relatively large head with flat crown and angled nape, long thick bill, and relatively longer tail than other eiders. Breeding plumage males display black cap, chin, collar, eye-ring, and rump, with white head and shoulders, light green patches behind the head and in front of the eye, cinnamon breast and shoulders marked with a black spot, and long dark purple-black tertial feathers with white stripes. Males in eclipse plumage are dark brown like females but retain white inner forewing. Both sexes have an iridescent bluish-purple speculum bordered with white along the entire length of the secondaries. Females are dark to cinnamon brown with pale-white eye-ring; juveniles are lighter brown with narrow white speculum edges and shorter tertial feathers. Feet are palmate with three fully webbed toes, dark bluish-grey.
Identification
Distinguished as the smallest eider with a relatively long tail and fast flight. Males in breeding plumage are unmistakable with their black and white head pattern, green patches, and cinnamon breast with black spot. The white inner forewing visible in flight distinguishes males even in eclipse plumage. Both sexes show the distinctive iridescent bluish-purple speculum with white borders. Compare to other eiders by smaller size, more compact build, and longer tail.
Distribution & Habitat
Three recognized breeding populations exist: Russian-Atlantic (west of Khatanga River in western Siberia, winters in Barents and Baltic seas), Russian-Pacific (east of Khatanga River, winters in southern Bering Sea and northern Pacific), and Alaska-breeding (Arctic Coastal Plain and Yukon-Kuskokwim Delta, winters in southern Bering Sea and northern Pacific). Less than 1% of the world population nests in Alaska. Non-breeding populations summer in northern Norway, Russia's east coast, and southwest Alaska. Habitat includes coastal bays and lagoons in winter; marshy tundra dominated by water sedge and pendant grass for breeding; and shallow coastal lagoons with eelgrass and tidal flats for moulting.
Behavior & Ecology
Forages primarily near shore by diving to 9 m maximum depth, wading, and dabbling; shows preference for small, highly mobile prey and crustaceans even when higher-energy prey available. Winter diet includes molluscs, echinoderms, polychaete worms, and mussels; summer diet includes aquatic insects, crowberries, and pondweeds. Reaches sexual maturity at 2 years; maximum lifespan 21 years 4 months. Males display at leks on wintering and breeding grounds, performing silent courtship with head-shaking displays. Breeding pairs form late winter to early spring; females build nests alone on moss and grass-covered mounds, laying 1-8 eggs incubated for 25 days. Young are precocial, feed independently immediately, and fly at approximately 40 days. Males produce low growling sounds; females make a 'qua-haaa' call; feathers produce mechanical whistling sound in flight. Moult occurs July to October; juveniles moult first, then adults.
Conservation
Global population estimated at 110,000-125,000 individuals (2016) and classified as vulnerable by IUCN. The Alaska-breeding population was listed as threatened in 1997 due to near disappearance of the Yukon-Kuskokwim Delta population. Primary threats include climate change causing tundra pond loss and predator-prey shifts, lead poisoning from shot consumption, nest predation by Arctic fox, pomarine jaeger, snowy owl, and common raven, disease (Avian Influenza with 0.2-5% infection rates and 80% with antibodies; E. coli), and natural resource exploitation causing habitat contamination. Recovery plans by the European Union and U.S. Fish and Wildlife Service are in effect; the US plan estimates $15,675,000 total cost with recovery predicted by 2050 if adequately funded. Critical habitat designation in 2001 protected approximately 7,300 km² and 1,370 km of coastline.
Culture
Legal harvest by waterfowl hunters in the United States ended in 1991. Egg collection and subsistence hunting continue in Alaska but are uncommon. The degree of subsistence hunting in Russia and its population effects are poorly documented.
Source: Wikipedia · CC BY-SA 3.0
Taxonomy
- Order
- Anseriformes
- Family
- Anatidae
- Genus
- Polysticta
- eBird Code
- steeid
Distribution
breeds northwestern and northeastern Siberia from Yamal Peninsula to Chukotka, and Arctic Coastal Plain, northern Alaska; winters to Kamchatka Peninsula, Commander and Kuril islands (southeastern Russia), and Aleutian Islands; also Kola Peninsula, Barents and White seas (northwestern Russia), and Baltic Sea
Data Sources
Species description from Wikipedia, licensed under CC BY-SA 3.0.
Taxonomy data from AviList 2025.