20-7-2025 ISAFJORDUR, ICELAND - COMMON EIDER (FEMALE) (Somateria mollissima)

The common eider (pronounced /ˈaɪ.dər/) (Somateria mollissima), also called St. Cuthbert's duck or Cuddy's duck, is a large (50–71 cm (20–28 in) in body length) sea-duck that is distributed over the northern coasts of Europe, North America and eastern Siberia. It breeds in Arctic and some northern temperate regions, but winters somewhat farther south in temperate zones, when it can form large flocks on coastal waters. It can fly at speeds up to 113 km/h (70 mph).

The eider's nest is built close to the sea and is lined with eiderdown, plucked from the female's breast. This soft and warm lining has long been harvested for filling pillows and quilts, but in more recent years has been largely replaced by down from domestic farm-geese and synthetic alternatives. Although eiderdown pillows or quilts are now a rarity—typically being marketed as luxury goods—eiderdown harvesting continues and is sustainable, as it can be done after the ducklings leave the nest with no harm to the birds.

Eiders are colonial breeders. They nest on coastal islands in colonies ranging in size of less than 100 to upwards of 15,000 individuals. Female eiders frequently exhibit a high degree of natal philopatry, where they return to breed on the same island where they were hatched. This can lead to a high degree of relatedness between individuals nesting on the same island, as well as the development of kin-based female social structures. This relatedness has likely played a role in the evolution of co-operative breeding behaviours amongst eiders. Examples of these behaviours include laying eggs in the nests of related individuals and crèching, where female eiders team up and share the work of rearing ducklings.

21-7-2024 ISAFJORDUR, ICELAND - COMMON EIDER (FEMALE) (Somateria mollissima)

The common eider (pronounced /ˈaɪ.dər/) (Somateria mollissima), also called St. Cuthbert's duck or Cuddy's duck, is a large (50–71 cm (20–28 in) in body length) sea-duck that is distributed over the northern coasts of Europe, North America and eastern Siberia. It breeds in Arctic and some northern temperate regions, but winters somewhat farther south in temperate zones, when it can form large flocks on coastal waters. It can fly at speeds up to 113 km/h (70 mph).

The eider's nest is built close to the sea and is lined with eiderdown, plucked from the female's breast. This soft and warm lining has long been harvested for filling pillows and quilts, but in more recent years has been largely replaced by down from domestic farm-geese and synthetic alternatives. Although eiderdown pillows or quilts are now a rarity, eiderdown harvesting continues and is sustainable, as it can be done after the ducklings leave the nest with no harm to the birds.

The common eider is both the largest of the four eider species and the largest duck found in Europe, and is exceeded in North America only by smatterings of the Muscovy duck, which only reaches North America in a wild state in southernmost Texas (and arguably south Florida where feral but non-native populations reside). It measures 50 to 71 cm (19+1⁄2 to 28 in) in length, weighs 0.81 to 3.04 kg (1 lb 12+1⁄2 oz to 6 lb 11 oz) and spans 80–110 cm (31–43 in) across the wings. The average weight of 22 males in the North Atlantic was 2.21 kg (4 lb 14 oz) while 32 females weighed an average of 1.92 kg (4 lb 3+1⁄2 oz). It is characterized by its bulky shape and large, wedge-shaped bill. The male is unmistakable, with its black and white plumage and green nape. The female is a brown bird, but can still be readily distinguished from all ducks, except other eider species, on the basis of size and head shape. The drake's display call is a strange almost human-like "ah-ooo", while the hen utters hoarse quacks. The species is often readily approachable.

Drakes of the European, eastern North American and Asia/western North American races can be distinguished by minor differences in plumage and bill colour. Some authorities place the subspecies v-nigra as a separate species.

This species dives for crustaceans and molluscs, with mussels being a favoured food. The eider will eat mussels by swallowing them whole; the shells are then crushed in their gizzard and excreted. When eating a crab, the eider will remove all of its claws and legs, and then eat the body in a similar fashion.

It is abundant, with populations of about 1.5–2 million birds in both North America and Europe, and also large but unknown numbers in eastern Siberia (HBW).

21-7-2024 ISAFJORDUR, ICELAND - COMMON EIDER (FEMALE AND JUVENILE) (Somateria mollissima)

The Eider is the UK's heaviest and fastest flying duck. It's a true seaduck, rarely found away from coasts. Its reliance on coastal shellfish for food has brought it into conflict with mussel farmers. Eiders are very sociable and usually stay close to shore, riding the swell in a sandy bay or strung out in long lines beyond the breaking waves. It is an Amber List species because of its winter concentrations.

Flocks of these large sea ducks enliven northern coastlines. Males are white and black with a soft suffusion of green on the nape. Immature males are variable and messy-looking with patches of black and white. Females vary from rich rufous-brown to cold grayish, always with extensive black barring covering body and wings. Slight variation in bill shape and color across subspecies, especially obvious on males; Pacific birds have brightest orange bills, most others have greenish bills. Dives to feed on mollusks and other crustaceans. In late summer, look for flocks of females with dozens of ducklings; broods often join together. Compare females with other eider species, and note details of bill and head shape.

21-7-2024 ISAFJORDUR, ICELAND - COMMON EIDER (MALE) (Somateria mollissima)

The common eider (pronounced /ˈaɪ.dər/) (Somateria mollissima), also called St. Cuthbert's duck or Cuddy's duck, is a large (50–71 cm (20–28 in) in body length) sea-duck that is distributed over the northern coasts of Europe, North America and eastern Siberia. It breeds in Arctic and some northern temperate regions, but winters somewhat farther south in temperate zones, when it can form large flocks on coastal waters. It can fly at speeds up to 113 km/h (70 mph).

The eider's nest is built close to the sea and is lined with eiderdown, plucked from the female's breast. This soft and warm lining has long been harvested for filling pillows and quilts, but in more recent years has been largely replaced by down from domestic farm-geese and synthetic alternatives. Although eiderdown pillows or quilts are now a rarity, eiderdown harvesting continues and is sustainable, as it can be done after the ducklings leave the nest with no harm to the birds.

21-7-2024 VIGUR ISLAND, ICELAND - COMMON EIDER (FEMALE) (Somateria mollissima)

The common eider (pronounced /ˈaɪ.dər/) (Somateria mollissima), also called St. Cuthbert's duck or Cuddy's duck, is a large (50–71 cm (20–28 in) in body length) sea-duck that is distributed over the northern coasts of Europe, North America and eastern Siberia. It breeds in Arctic and some northern temperate regions, but winters somewhat farther south in temperate zones, when it can form large flocks on coastal waters. It can fly at speeds up to 113 km/h (70 mph).

The eider's nest is built close to the sea and is lined with eiderdown, plucked from the female's breast. This soft and warm lining has long been harvested for filling pillows and quilts, but in more recent years has been largely replaced by down from domestic farm-geese and synthetic alternatives. Although eiderdown pillows or quilts are now a rarity, eiderdown harvesting continues and is sustainable, as it can be done after the ducklings leave the nest with no harm to the birds.

The common eider is both the largest of the four eider species and the largest duck found in Europe, and is exceeded in North America only by smatterings of the Muscovy duck, which only reaches North America in a wild state in southernmost Texas (and arguably south Florida where feral but non-native populations reside). It measures 50 to 71 cm (19+1⁄2 to 28 in) in length, weighs 0.81 to 3.04 kg (1 lb 12+1⁄2 oz to 6 lb 11 oz) and spans 80–110 cm (31–43 in) across the wings. The average weight of 22 males in the North Atlantic was 2.21 kg (4 lb 14 oz) while 32 females weighed an average of 1.92 kg (4 lb 3+1⁄2 oz). It is characterized by its bulky shape and large, wedge-shaped bill. The male is unmistakable, with its black and white plumage and green nape. The female is a brown bird, but can still be readily distinguished from all ducks, except other eider species, on the basis of size and head shape. The drake's display call is a strange almost human-like "ah-ooo", while the hen utters hoarse quacks. The species is often readily approachable.

Drakes of the European, eastern North American and Asia/western North American races can be distinguished by minor differences in plumage and bill colour. Some authorities place the subspecies v-nigra as a separate species.

This species dives for crustaceans and molluscs, with mussels being a favoured food. The eider will eat mussels by swallowing them whole; the shells are then crushed in their gizzard and excreted. When eating a crab, the eider will remove all of its claws and legs, and then eat the body in a similar fashion.

It is abundant, with populations of about 1.5–2 million birds in both North America and Europe, and also large but unknown numbers in eastern Siberia (HBW).