EIDER, or EfDER-DUCK (somateria), a genus of oceanic ducks, having the hind-toe furnished with a deep lobe, and the bill swollen and elevated at the base, and extend ing up the forehead, where it is divided down the middle by an elongated projection of feathers. The tertials are elongated, and fall down over the wing. This genus is fur ther characterized by the very abundant development of a fine elastic gray down, partic ularly on the breast, the valuable eider-down of commerce.—The COMMON E. (S. mol lissima) is intermediate in size between a common duck and a goose; not much exceed ing the common duck in entire •ength, because of the comparative shortness of the neck, characteristic of the oceanic ducks, but being about twice its weight. The male is larger than the female; and in the breeding season, has the under parts black, the upper parts and the neck white, the crown of the head velvety black, the cheeks green ish white. After the breeding season, the white color almost disappears from the upper parts, and gives place to black, without change of feathers. The female is of a pale-brown color, tinged with red, and varied with transverse marks of dark brown. Young males at first resemble the females, and do not acquire the full adult plumage till their third winter. The young are termed brattocks in many parts of Scotland. The E. is an inhabitant of the northern parts of the world. abounding on arctic and subarctic shores, and becoming rarer in more southern and temperate regions. It is merely an occasional winter visitant in the middle latitudes of Europe, and the Fern islands are its most southern breeding-place on the British coast. In North America it seldom breeds further s. than the hay of Fundy. Great numbers breed on the coasts of Labrador and more northern parts of America, where hitherto the gathering of the down has been generally neglected; but in Iceland and Norway the breeding-grounds of eiders are carefully protected', and are transmitted as valuable inheritances from father to son. Cattle are sometimes removed from islets, in order to induce the eiders to settle upon them, and a strict watch is kept against dogs and foxes. Promontories
are sometimes even formed into artificial islets, on the same account, as the E., like many other sea-birds, prefers islands for its breeding-places, probably on account of their greater quiet and security. The nest is formed of fine sea-weeds, mosses, and dry twigs, if they are to be had, matted and interlaced. The eggs are usually five, sometimes six or seven in number, about Tin. long, and fully 2 in. broad, of a uniform pale green: they are at first deposited without any down, but as incubation proceeds, the mother strips the down from her breast, and places it about them. By it they are kept warm when she at any time has occasion to leave them, but it seems to be indis pensable to their being hatched; for if the 'eggs and down are removed, and if this is done a second time, so that the female cannot afford a further supply, the male comes and contributes for the third set of eggs•the down of 'his breast, which is of a paler color. The common practice in Norway and Iceland is to take away the eggs and down twice, leaving -the third set of eggs to increase the number of the species. The eiders of the Icelandic and Norwegian breeding-grounds show so little alarm at the approach of visitors that the females will permit themselves to be touched as they sit on their nests, the males moving about close beside them, but agitated and disturbed. The nests are often placed so close together that great care is necessary in walking among them to avoid trampling upon them. In the islet of Vidoe, a valuable breeding-ground near Reikiavik, the capital of Iceland, almost every little hollow place between the rocks is occupied by the nests of these fowls; they readily take possession of holes cut for them in rows in the sloping side of a hill; nay, garden-walls and the interiors of buildings are in like manner occupied. In Orkney and Shetland the E. is commonly known by the name of dunter-duck.