Kingdoms / Animalia / Craniata / Aves / Anseriformes / Anatidae / Somateria / Species
< > Somateria mollissima - Common eider (Click photographs/illustrations: full picture & further details)
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INFORMATION AVAILABLE

GENERAL & REFERENCES

EXTERNAL APPEARANCES

REPRODUCTION

BEHAVIOUR

NATURAL DIET

RANGE & HABITAT

CONSERVATION

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General and References

Alternative Names (Synonyms)

Eider
Eider duck
Eiderente (German)
Eider à duvet (French)
Eider ordinaire (French)
Eider común (Spanish)
Eidero comun (Spanish)
Eidereend (Dutch)
Ejder (Swedish)
Somateria mollissima mollissima European eider
Somateria mollissima faeroeensis Faeroe eider
Somateria mollissima v-nigra Pacific eider
Somateria mollissima borealis Northern eider
Somateria mollissima sedentaria Hudson Bay eider
Somateria mollissima dresseri American eider

Names for newly-hatched

Duckling, downy.

Names for non-breeding males or other colour-phases

Eclipse

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References

Species Author

Debra Bourne

Major References

B1, B2, B3, B6, B8, B19, B25, B26, B27.

Aviculture references:
J23.13.w8
B7, B29, B30, B31, B40,B94, B96, B97, B108, B129
D1, D8

ORGANISATIONS
(UK Contacts)

ELECTRONIC LIBRARY
(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

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TAXA Group (where information has been collated for an entire group on a modular basis)

Parent Group

Specific Needs Group referenced in Management Techniques

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Aviculture Information

Notes

General information:
  • Seaducks are generally winter-hardy and sociable. They are preferably kept on a large area of clean, cold, deep water, at least some of which (preferably half the area) should be more than 60cm and preferably more than1m deep. As with other diving ducks, most species are relatively ungainly on land and ponds should have shallow sloping banks. Some cover along the pond edges will generally be appreciated. Preferred nesting sites vary greatly within this group, from open ground nesting to thick vegetation and tree holes.
  • Diets of grain, pellets fish and seafood may be used, also bread. These ducks generally need a higher-protein diet than most waterfowl species and high-protein pelleted diets specifically designed for seaducks are now available, although supplementation with fish may still be important particularly for breeding.
  • Feeding in troughs containing stones may avoid the development of overgrown bills. Provision of salt water may decrease the incidence of fungal and other infections.
  • Ducklings may be given high-protein starter crumbs and live food, and provided with access to deep water for swimming from an early age.
  • Eiders should be provided with clean, deep, cold water, with ice-free water available in winter, and may be best kept as flocks rather than as individual pairs. They will eat large quantities of fish if it is offered. They are prone to Foreign Body Ingestion while searching for grit, and are also susceptible to heat stress and to Aspergillosis.

(B7, B29, B30, B40, B94, B129, D1)

Species-specific information:

  • Common eiders are winter-hardy, easy to maintain and not quarrelsome.but may suffer in summer from heat. Clear, cold running water is ideal, and some shade should be available on shores. High-protein feed, plus grain, and e.g. shrimps or fish may be fed and a good grit supply is important.
  • Some subspecies are fairly easy to breed. They prefer to lay in close or open ground cover: in grass or other vegetation on islands, or in bankside vegetation, and they also use ground level nest boxes or baskets. Usually lay in May, rarely April (B31), mainly May to June (B29). These ducks are reliable incubators, but hand-rearing is recommended, being easier for controlling feeding, on clear water and with plentiful food (B31).
  • Hybrids have been mentioned with Somateria spectabilis - King eider, Anas acuta - Northern pintail, , Anas platyrhynchos - Mallard.

(J23.13.w8, B29, B31, B94, B96, B97, B108, B129)

Aviornis UK Ringing Scheme recommended average ring size: (D8).

  • Somateria mollissima mollissima European eider N 13.0mm
  • Somateria mollissima faeroeensis Faeroe eider M 12.0mm
  • Somateria mollissima v-nigra Pacific eider P 14.0mm
  • Somateria mollissima borealis Northern eider N 13.0mm
  • Somateria mollissima dresseri American eider N 13.0mm
Individual Techniques linked in Wildpro

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External Appearance (Morphology)

Measurement & Weight

Length 22-28 inches 56-71cm (B3); 50-71cm (B1)
Adult weight General 1915-2218g (B1)
Male mollissima mean 2266 (B25); mean 5.0 lbs. (B8).
Female mollissima mean 2028g (B25); mean 4.5 lbs. (B8).
Newly-hatched weight --
Growth rate --

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Head

Adult Bill Male Somateria mollissima mollissima olive grey, more yellow on (large) nail and towards base (greyer in autumn).
Variations (If present) Female: olive-grey/olive-yellow.

Other subspecies, male bill grey-green, yellow or orange.

Eyes (Iris) Male Brown.
Variations(If present) --
Juvenile Bill Olive-grey/olive-yellow.
Eyes (Iris) Brown.

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Legs

Adult Male Olive green with blackish webs.
Variations (If present) Female: more grey-green.
Juvenile Grey-green.

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Plumage

Adult Male
Click Illusration for full-page view
Crown from bill and ventrally to just below eyes black with central white line from mid-crown to nape. Dorsal half of neck pea-green, divided by white line down neck. Rest of head, neck, breast and upperparts white, with buff/pink on breast. Flanks, abdomen, tail, tail coverts and rump black; sides of rump white in patch extending ventrally. Secondaries and primaries black.
Variations (If present)
Click Illustration for full-page view
Female: brown with breast and flanks black-barred, black centres to feathers on upperparts. Wings brown with dark brown secondaries and primaries, white tipping to secondaries and greater wing coverts (visible as two lines when wing folded). Less barred in summer.

Somateria mollissima v-nigra: black v-shape line on throat.

Juvenile Duller, plainer brown than female.

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Newly-hatched Characteristics

General: Upperparts sepia-brown, underparts paler, red-buff eyebrows.
Bill: Dark olive-grey.
Feet: Dark olive-grey.

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Reproduction

Reproductive Season

Time of year Begins April/May (as late as mid-June further north).
No. of Clutches --

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Nest placement and structure

Low-lying coasts and islands, rarely lakes/rivers a few miles from sea. hollow on ground, sheltered by rocks/vegetation, thick down lining.

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Egg clutches

No. of Eggs Average 4-6 (B1).
Range 1-8 (B1); 36 (B8)
Egg Description Pale brown, olive-green or greyish.

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Incubation

25-28 days (B1); 2530 days (B8).

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Hatching

Synchronous

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Fledging

65 - 75 days (B1, B8).

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Sexual Maturity

Males Three, occasionally two years old.
Females Three, occasionally two years old.

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Behaviour

Feeding Behaviour

Adults Dive, also head-dip and upend in shallows.
Newly-hatched --

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Parental Behaviour

Nest-building By female, in colonies.
Incubation By female.
Newly-hatched By female; brooded at night initially.
Juveniles

Tend to form crèches of e.g. 10-100 ducklings, with several females, including non-breeding 'aunties'.

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Social Behaviour

Intra-specific Gregarious.
Inter-specific Mix with other species such as Somateria spectabilis - King eider in winter. Hybridise with Somateria spectabilis - King eider occasionally on Iceland (B8, B25).

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Sexual Behaviour

Seasonal pair bond but occasional male promiscuity.

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Predation in Wild

--

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Activity Patterns

--
Circadian --

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Natural Diet

Adults

Mainly molluscs and crustaceans, particularly blue mussel, also echinoderms, other marine invertebrates, occasionally small fish; algae, berries, seeds and leaves of plants used by breeding female.

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Newly-hatched

Small snails, shrimps.

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Range and Habitat

Distribution and Movement (Migration etc.)

Normal
  • Somateria mollissima mollissima North-western Europe from coasts of Scotland and Scandinavia eastward to Novaya Zemlya and Vaigach Island. Mainly sedentary but as far south as France, occasionally Spain, Italy in winter.
  • Somateria mollissima faeroeensis Faeroe Islands. Sedentary.
  • Somateria mollissima v-nigra From New Siberian Islands eastward through north-eastern Siberia, on islands in Bering Sea to north-western North America (Cook Inlet north-westward and Arctic Ocean coast to Victoria Island and Coronation Gulf. Winters around Aleutian Islands in Bering Sea
  • Somateria mollissima borealis Across the Arctic Atlantic from Baffin Island eastward, to Greenland, Iceland and Franz Josef Land. winters southern Greenland and Labrador southward to Nova Scotia, rarely New England.
  • Somateria mollissima sedentaria Hudson Bay area, winters mainly around Belcher Islands.
  • Somateria mollissima dresseri Atlantic north-eastern North America (coasts of Labrador, Newfoundland, Quebec, Nova Scotia, New Brinswick, Maine) Winters from Gulf of St Lawrence to Massachusetts and eastern Long Island.

London: In the London Area, "scarce visitor, usually in winter." Individual once present may remain for some time (1.5 years is not unprecedented. (J322.65.w1)

Partly migratory. Males generally remain further north than females and juveniles. At sea out of breeding season.

Occasional and Accidental

--

Introduced

--

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Habitat

Shallow inshore waters, estuary mouths. Occasionally on inland freshwater lacks on migration or in winter.

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Conservation

Intraspecific variation

Somateria mollissima mollissima European eider
Somateria mollissima faeroeensis Faeroe eider
Somateria mollissima v-nigra Pacific eider
Somateria mollissima borealis Northern eider
Somateria mollissima sedentaria Hudson Bay eider
Somateria mollissima dresseri American eider

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Conservation Status

Wild Population -
(Importance)

Widespread and locally abundant (B1).

CITES listing --
Red-data book listing --
Threats Oil spills could affect whole flocks (B8)..

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Captive Populations

Reasonable presence in collections (B8).

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Trade

--

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