Common Eider

The common eider, known scientifically as Somateria mollissima, is a large sea-duck that captivates with its considerable size, ranging from 50 to 71 cm in body length. It is the largest of the four eider species and, in Europe, it is the largest duck present. In North America, it is only surpassed in size by the Muscovy duck in certain locales. The common eider is a robust bird, with males displaying a striking black and white plumage and a distinctive green nape, while females are cloaked in brown, yet both sexes are recognizable by their large, wedge-shaped bills.

Identification Tips

The male common eider is unmistakable with its contrasting black and white feathers and verdant nape. The female, though predominantly brown, can be distinguished from other ducks by her size and head shape. The drake's unique display call resembles a human-like "ah-ooo," and the hen's voice is characterized by hoarse quacks. The species is often approachable and can be identified by its bulky shape and size.

Habitat

Common eiders are found nesting close to the sea, often on coastal islands where they form colonies. They prefer Arctic and northern temperate regions for breeding but migrate slightly south to temperate zones during winter.

Distribution

This species graces the northern coasts of Europe, North America, and eastern Siberia. It breeds in the Arctic and some northern temperate regions, wintering farther south in temperate zones where it may gather in large flocks on coastal waters.

Behaviour

Eiders are colonial breeders, with colonies varying from less than a hundred to over 15,000 individuals. They exhibit natal philopatry, with females often returning to their birthplace to breed. This has led to the development of kin-based social structures and cooperative breeding behaviors, such as shared rearing of ducklings.

Song & Calls

The male common eider's display call is a distinctive "ah-ooo," while the female emits hoarse quacks. These vocalizations contribute to the bird's unique auditory presence in its natural habitat.

Breeding

The eider's nest is built near the sea and is lined with the female's own eiderdown, a soft and warm material once harvested for human use. The species demonstrates cooperative breeding behaviors, including shared rearing of ducklings in crèches.

Similar Species

While the male common eider is unique in appearance, the female may be confused with other eider species. However, size and head shape are key distinguishing features.

Diet and Feeding

The common eider dives for crustaceans and molluscs, with mussels being a preferred food. It consumes mussels whole, crushing the shells in its gizzard. Crabs are also on the menu, with the eider skillfully removing claws and legs before consumption.

Conservation status

The common eider is currently classified as Near Threatened on the IUCN Red List. Populations are estimated at 1.5–2 million birds in both North America and Europe, with additional, albeit unknown, numbers in eastern Siberia. Conservation efforts and studies, particularly in Canada's Hudson Bay, are ongoing to monitor and support the species' recovery.