Saturday, 2 February 2013

Common Eider

order : Anseriformes      Genus & Species : Anatidae     Family : Somateria mollissima

The common eider spends most of its time in the cold, storm-tossed waters of northern seas, buoyantly bobbing among rough wave crests or diving below the surface to feed. Cold-cheating down feathers insulate the common eider against icy seas and a powerful, shell-cracking bill helps it exploit abundant shellfish. They found on coasts from Alaska, across northern Canada and northeastern U.S. to Greenland, Great Britain, Scandinavia and eastern Siberia; birds in the High Arctic and Baltic areas migrate south in winter. 

Habitat : The common eider is essentially a seaduck, spending most of its life offshore along cold, bleak and inhospitable sea coasts, from the North Atlantic and Pacific, north to the High Arctic. It sometimes flies to inland lakes and rivers, but visits only those waters that are a short distance away from the coast. Rarely venturing far out to sea, the common eider prefers to remain close inshore, seeking the shelter of protected bays, inlets and estuaries.These sheltered areas also offer ideal breeding sites, as the common eider tends to nest very close to the water, just out of range of the pounding surf. 
Food & Feeding : The eider feeds on a variety of shellfish (mussels, whelks, cockles and crabs), which it finds on the seabed. At high tide, the eider dives beneath the waves to grab shellfish in its powerful bill or, as the tide ebbs, it dabbles for them in the shallows. The eider cracks open large shellfish with its bill, but swallows small ones whole. The gizzard (part of the stomach) grinds down the shells of the food that it swallows whole, releasing the soft flesh inside. Shellfish form the basis of the eider’s diet, but it also occasionally eats small fish. While incubating her eggs, a female may nibble away at plant matter that’s within reach of the nest, such as berries, seeds and leaves. 
Behavior : Common eiders gather in large flocks on coastlines; they spend most of their time resting between feeding sessions. The sociable birds also come onto land to loaf about and preen. When moving from place to place, they usually fly in single file or in loose strings. Eiders winter mainly within their breeding range out at sea, although eiders from the Baltic and Arctic areas may be driven to coasts farther south when the polar seas freeze over. 
Breeding : Courtship occurs in flocks. Drakes (males) circle females in the water, cooing softly. A female accepts by imitating his display, then allows him to mate with her. The pair goes ashore to find a nest site. Once a site is selected, the pair separates. Eiders nest in colonies, and egg-laying within a colony is synchronous (most clutches hatch within a short time of each other). Ducklings are active as soon as they hatch; within hours, females lead their young to the sea, where they plunge in, quickly learning to dive and find food. The young are fledged at about 10 weeks. 

Bill : Large, triangular bill is employed for cracking open mussels, crabs, whelks and other shellfish. 
Feathers : Under the outer body feathers is a thick layer of down.These small, soft and loosely structured feathers trap a layer of air close to the skin, giving the eider excellent protection against the cold. 
Feet : Feet are large and broadly webbed, providing the eider with the thrust needed to dive down to the seabed to feed. 
Female : In contrast to the drake’s bold, black-and-white breeding plumage, the female is a uniform brown with blackish stripes and bars all year round. This provides camouflage when the female is nesting. 

Weight : 4–5 lbs.
Length : 1.5-2'
Wingspan : 2.5-3.5'
Sexual Maturity : 2-3 years
Breeding Season : April–July

It’s believed that the common eider inspired the first bird sanctuary. St. Cuthbert, a 7th-century hermit on the Farne Islands off the east coast of northern England, protected them. In fact, the Farne Islands are still a bird sanctuary today.

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