The name Merganser, that is, 'Diving Goose', has reference to the size of the bird and its habit of diving for its food. Its flight is strong and rapid, but differs somewhat from that of the Ducks, the neck being not stretched out to its full length, but slightly folded back. After the young are hatched the male deserts the female and leaves her to bring off her brood without assistance.
Crest, neck, scapulars, smaller wing-coverts, and all the under parts white; cheeks and back of the head greenish black; two crescent-shaped marks advancing from the shoulders on each side to the breast black; tail ash coloured; bill and feet bluish grey, the membranes black; irides brown. Length seventeen inches. _Female_ smaller; head and cheeks reddish brown; under parts white, clouded on the breast, flanks, and rump, with ash-grey; upper plumage and tail greyish black; wings variegated with black, white, and grey. Eggs whitish.
The birds of this genus, though placed among the Anatidæ, or Duck tribe, are so strongly marked by the conformation of the bill that a simple examination of the head alone will enable the student to distinguish either of the species from the true Ducks already described. On the coast of Norfolk the popular name 'Smee Duck' includes several kinds of Ducks, and I presume the present species; but the bill, in the form of an elongated and almost cylindrical cone, with the edges of both mandibles furnished with saw-like teeth pointed backwards, cannot fail to distinguish the genus _Mergus_.
The Smew, or Smee, properly so called, is a winter visitor with us, more impatient of cold than the Duck-tribe generally, and consequently frequenting the southern more than the northern parts of the island. In open weather it resorts to our rivers and fresh-water lakes, where it feeds on small fish and other aquatic animals, which it obtains by diving. In severe frosts it either flies farther south or repairs to tidal rivers and harbours. Though not a rare bird, it is sparingly distributed. It is found on many of the continental rivers, even those which are far distant from the sea, but is not often killed, as it is shy of being approached, readily takes wing, flies swiftly, and as a diver is most rapid and expert. It is, however, little sought after, for, in spite of its relationship, its strong fishy flavour prevents it from passing muster as a Duck. Of its nesting little or nothing is known. In the north of Devon it is called, according to Montagu, 'Vare Wigeon', from the supposed resemblance of its head to that of a 'vare' or weasel. I have also heard it called the 'Weasel Duck' in Norfolk, and on the south coast the 'Weasel-headed'.