The Smew — Mergus Albellus, Linnæus
This species, the smallest and scarcest of the Sawbills, only comes to us in the winter, its breeding haunts being near the limit of tree growth throughout Northern Europe. It may be found on inland rivers and lakes, as well as in sheltered bays and estuaries on the coast. Immature examples with a red head, known as “Red-headed Smews,” far out-number the adults, and old males in full plumage are rarely seen.
This is one of the species that occupies the boxes in Sweden and Lapland, and the discovery of its eggs, fifty years ago, was due to the energy and perseverance of an Englishman, John Wolley, who, after four years’ search, succeeded in obtaining three eggs together with a sitting bird. The eggs are cream coloured and not unlike those of the Wigeon, but they are slightly smaller.
The adult male is entirely white, except for the mantle and quills, which are jet black. The rump, upper tail coverts, and tail are bluish grey, and the flanks delicately vermiculated with the same colour. Stretching half-way across the breast is a narrow black bar, and a shorter but broader one starts a little farther back. There is a black patch between the bill and the eye on each side, and another high up on the occiput joining its fellow on the opposite side, this black crescent being broken by the overlapping of the slightly elongated feathers of the head.
The “eclipse” plumage somewhat resembles that of the immature male, from which it may always be distinguished by the mantle remaining black. The female is smaller; head and neck reddish brown; remainder of upper parts and breast ashy grey; under parts white. Length 17·5 in.; wing 7·6 in.