The Long-Tailed Duck is described by Willughby under the name of _Anas caudacuta Islandica_. by the natives called _Havelda_. Selby and modern ornithologists have preserved the Iceland name in _Harolda_.
Prolongations of the bill flat; upper part of the head velvet-black, with a central whitish band, lower greenish white; neck and back white; breast ringed with red; lower plumage black; bill and feet greenish grey; irides brown. _Female_--general plumage reddish brown, with transverse black bars; wing-coverts black, bordered with dark reddish brown; two whitish bars across the wing; belly brown barred with black. Length twenty-five inches. Eggs shining greenish grey.
The Eider Duck differs from all the birds of the same tribe hitherto described, in being essentially and absolutely a sea-bird. Rarely found on inland waters, it does not even visit the fresh-water lochs which, in many places in the north, are only separated from the sea by a bar of sand and shingle. It spends the greater part of its time on the water, and feeds on fish, molluscs, and other animal matter which it can obtain by diving. In the latter art it is very expert, and when pursued by the fowler generally manages to escape, as it can remain a long time under water, and on rising to the surface is ready to descend again almost instantly. Though a northern bird, it is subjected to no privations by the freezing of lakes and marshes, since it finds its rest and food on the open sea. Consequently it is not migratory, and stray specimens only visit the southern shores of England. Where it was bred, there, probably, or not far off, it remains all the year round. The Farn Islands, off the coast of Northumberland, are considered to be the extreme southern limit of its breeding-ground. In the Hebrides, the Orkneys and Shetland Islands, it is quite at home, but in none of these places is it found in sufficient numbers to give it importance. It is rare on the Irish coast.
In the Arctic regions, in Iceland, and on the rocky coasts of Norway and Sweden, Eider Ducks are very numerous. In Labrador, Audubon informs us, they begin to form their nests about the end of May or the beginning of June. 'For this purpose some resort to islands scantily furnished with grass; others choose a site beneath the spreading boughs of stunted firs, and, in such places, five, six, or even eight are sometimes found beneath a single bush; many are placed on the sheltered shelvings of rocks a few feet above high-water mark. The nest, which is sunk as much as possible into the ground, is formed of sea-weeds, mosses, and dried twigs, so matted and interlaced as to give an appearance of neatness to the central cavity, which rarely exceeds seven inches in diameter. In the beginning of June the eggs are deposited, the male attending upon the female the whole time. The eggs, which are regularly placed on the moss and weeds of the nest without any down, are generally from five to seven. When the full complement of eggs has been laid the female begins to pluck some down from the lower part of the body; this operation is daily continued for some time, until the roots of the feathers, as far forward as she can reach, are quite bare. This down she disposes beneath and around the eggs. When she leaves the nest to go in search of food, she places it over her eggs to keep up their warmth.'