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Eider

size:

50-71 centimeters; 80-108 centimeters wingspan

color (adults):

male: black and white plumage, green neck, female: brown

food:

shellfish, periwinkles, small crabs, sometimes starfish or fish

threats:

overfishing (compeition), oil pollution

Dutch status:

nesting bird, winter guest

habitat

sea, mud flats

reproduction:

maturity: 3 years, 4-6 eggs

life span:

18 years (maximum record: 35.5 years)

special nature:

eider creches: females help each other in rearing the chicks.

  • Dut: Eidereend (eider)
  • Eng: Common Eider
  • Fren: Eider à duvet
  • Ger: Eiderente
  • Ital: Edredone
  • Lat: Somateria mollissima
  • Dan: Edderfugl
  • Nor: Ærfugl
  • Fries: Eidergoes
Common Eider, Jeroen Reneerkens (jeroenreneerkens@hetnet.nl)

Eider

Eiders are bulky ducks with a large wedge-shaped bill. In fact, it is their bill and their flattened head that make them easy to identify. Males are unmistakeable with their black-white plumage and characteristic 'ah-hoo' call. Downy feathers from eiders are the best in the world. Females line their nests with this material. In Iceland, people gather the feathers for making comforters and pillows.

On Texel


female Eider, foto fitis, adriaan dijksen

The first pair of eiders nested on Texel in 1946. Since around 1965, around 100 pairs of eiders nest yearly on Texel. In the winter, you find thousands of eiders along the wadden coast of the island. Most are only here during the cold season.

  • Strong stomach

    Eiders swim and dive to find their food. They can dive as deep as 10 meters. They go after shellfish living on the sea floor. The beak of the eider is so sensitive that it is capable of judging the proportion meat-water-shell of the shellfish.
    Scientists from IMARES have calculated the total food requirements for eiders in the Wadden Sea to be 14.7 million kilograms of shellfish meat per year. They swallow their entire prey. Their strong stomach muscles grind the shells and whatever is inedible is excreted. Although they eat primarily shellfish, some eiders have been seen swallowing a fish.

  • Distribution of eiders
    Distribution of eiders, North Sea region, Ecomare
    Source: Important bird areas for Seabirds in the North Sea

    The eider first started to nest in the Netherlands in the beginning of the 20th century. Their nesting territory has been spreiding south for two centuries now, without them deserting the northern nesting grounds. Thanks to the decline in eider hunting this expansion has been possible.

  • Winters with many deaths
    Eiders, foto fitis, adriaan dijksen

    Eiders are sensitive to changes. There can be many birds in one year, and a sudden decline in the following year. In the winters of 1999/2000 and 2001/2002, a notable number of eiders died along the Dutch coast. IMARES was commissioned to investigate the problem. The shellfish contained so little meat in those winters that the eiders died from malnutrition.

  • Protection
    • Monitoring: Network Ecological Monitoring
    • Policy: Target Species List
    • National legislation: Flora and Fauna Regulation
    • European Agreement: Bird Directive
    • International: Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA), Bern Convention, Bonn Convention
  • Help with upbringing

    Young female eider ducks sometimes lay eggs in nests of relatives. They enlist the help of their grandmother or aunt in rearing their young. Studies have shown that young mothers prefer to lay their eggs in nests of older females. The number of odd eggs in the nest increased with age of the brooding duck. Three very old grannies in the study, at least 15 years old, had even only eggs in their nest laid by other eiders. The scientists think that some older females are no longer capable of laying a nest full of eggs and therefore are given the eggs belonging to a daughter, niece or granddaughter. These young females probably lay more eggs than they are capable of brooding. By dividing up the eggs, both parties benefit; the real mother can raise extra young and the host mother increases her reproduction success via relatives, without having to lay the eggs herself.

  • Eider crèche

    Should you happen to bike along the wadden dike in June, you're bound to see crèches with young eider chicks swimming in the sea. A small club of eider females accompanies not only their young but those of their neighbors as well. The chance of their survival is dependent upon the alertness of the mothers. Wandering chicks are quickly grabbed by hungry gulls. Studies have shown that eider chicks living in relatively small crèches have more chance of reaching adulthood than those living in large crèches.