Eider

Lifespan

15–20 years in the wild

Size & Weight

50–71 cm, wingspan 80–108 cm; 1.0–2.3 kg

Habitat

Shallow coastal waters, estuaries, and rocky shores, with a preference for areas with kelp beds and mussel populations.

UK Distribution

Resident and migratory; breeds in Scotland and northeastern England, particularly the Farne Islands and Shetland. Winter populations are boosted by visitors from Scandinavia and Russia.

Diet

Benthic invertebrates, primarily mussels and other bivalves, along with crustaceans, sea urchins, and occasionally small fish.

Prey

Mussels (Mytilus edulis), cockles, clams, crustaceans, echinoderms

Predators

Great black-backed gulls, white-tailed eagles, mink, and occasionally grey seals; eggs and ducklings vulnerable to herring gulls and corvids

Mating Season

December to June, with peak activity February to April

Breeding

Clutch size 3–5 eggs; incubation period 26–30 days by female alone; single brood per year; ducklings fledge at 8–9 weeks

Things With Wings

Species Profile

Sources and editorial status