EIDER DUCK.
No Duck is more thoroughly attached to the sea than this species, the Anas mollissima of Linnæus and Latham, but the Somateria mollissima of most modern ornithologists. Unfortunately it is somewhat restricted in its distribution, only breeding in one locality on the English coast, occurring more or less accidentally elsewhere. Ireland is not even so fortunate, for no nesting station is known round the entire coastline of the island. The Eider Duck is a decidedly northern bird, and is found, if somewhat locally, round the coasts of Scotland, extending to the outlying islands, including St. Kilda, where I have taken its nest. To most people, perhaps, the down of the Eider Duck, in the form of a coverlet, is more familiar than the bird itself. Although somewhat clumsy in appearance, the male Eider is a singularly handsome and conspicuous bird—conspicuous, one might say, when standing on the rocks or paddling about the still water near the shore, but even in a very moderately rough sea the bird is detected with difficulty, especially at a distance, for the white crests and dark waves effectually harmonise with, and conceal, its striking piebald plumage. The two predominating colours of the male Eider are black and white, the latter occupying most of the upper surface, the former most of the lower; the head, however, is variously marked with black, white, and pale green. The female is dark chestnut-brown, variegated with brownish-black. The Eider Duck is so thoroughly sea-going in its habits, that it rarely even flies over the land, except to reach its nest, and will rather follow the windings of the coast than cross even a narrow headland. In our islands it is practically sedentary, only wandering south a little way during winter. Its favourite haunts are rocky islands and coasts, where bays and quiet fjords offer it a haven of safety. The Eider is not so gregarious as many other Ducks, but it may be seen in parties all the year round, the drakes keeping company on the sea while their partners are on their nests, and when these latter come off them to feed, all join into a scattered company. The male bird is exceptionally wary at all times, but the female during the nesting period, becomes absurdly tame in districts where not persecuted, often allowing an observer to stroke her gently whilst she sits upon her eggs. The food of the Eider Duck consists of minute marine insects, crustaceans, and shellfish, especially mussels and small crabs. Most of this food is obtained by diving, the Eider being marvellously expert at this, not only descending to a great depth, but remaining for a long time below. A favourite method of feeding with this species is to draw shorewards with the tide. It may be watched gradually swimming towards the land in some sheltered bay, feeding as it comes, until the very edge of the breakers is reached. Then comes by far the prettiest sight of all, as the bird swims through each mighty wave just before it turns over and breaks upon the beach, floating light as a foam fleck on the huge rollers, now high up on the white crests, then momentarily lost to view in the green glassy depths. If alarmed on these occasions, the Eider generally swims quickly out from shore, but if further pursued or fired at, it instantly takes wing, rising from the water with little splash, and flying rapidly and steadily just above the surface to a safer refuge. The Eider is a day feeder, abroad at dawn, and continuing its labours well into the dusk. As a rule the Eider is a very silent bird. The usual note is a somewhat low kurr, but in the season of courtship the male utters a cooing sound when paying his addresses to his mate, as he swims round and round her, guarding her from the attentions of rivals. This cooing noise may be heard for a long distance across a quiet loch, especially, as often happens, if several drakes are together.
The favourite nesting places of the Eider Duck are low, rocky islands, well covered with marine vegetation, such as campion, thrift, and grass. Late in spring the flocks begin to separate more into pairs, although the immature non-breeding individuals may be observed to continue gregarious all the summer, and not to visit the nesting stations. The laying season is in May and June. The female alone selects a site for and makes the nest, the male rarely, if ever, visiting the spot, although he keeps in attendance on the sea near the islands, and joins her when she comes to feed. The nest is made upon the ground, sometimes amongst the dense beds of campion, sometimes in a crevice of the boulders, or on a ledge of rock. Occasionally, as I remarked at St. Kilda, it may be placed on the top of cliffs hundreds of feet above the sea. It is large and well made, consisting of coarse grass, dry seaweed, heather, and bits of dead vegetation, profusely lined with down and a few curly feathers from the body of the female alone. This lining gradually accumulates as the eggs are laid. Numbers of nests may be found close together, especially where the birds are tolerably common, as, for instance, at the Farne Islands, where, by the way, the Eider is known as “St. Cuthbert’s Duck.” The eggs are from five to seven, or rarely even eight, pale olive-green or greenish-gray in colour, and smooth and wax-like in texture. In many places the Eider is jealously protected for the sake of its precious down, especially in Iceland and Norway, and the taking of the eggs or down by unauthorized persons is an offence punishable by law. Outside our limits, the Eider inhabits most of the coasts and islands of the North Atlantic. The much rarer King Eider, Somateria spectabilis—an occasional visitor to the British Seas—claims a passing reference, for it is by no means improbable that the species actually breeds within our limits.