The real original or typical sheldrake, a well-known sea-coast bird at home, and the only surface-feeding duck which is a sea-bird anywhere, is a rather rare winter bird only in India, being only at all common in Sind, where it is called Niruji, and not going far south anywhere, though it ranges east to Upper Burma. The Hindustani names of Safaid Surkhab and Chandi Hans, however, which are in use as well as that given above, show that the natives know the bird well, and it is one that once seen is never forgotten—its predominant white colour, indicated by its native names, and set off by a black head and wing-tips, chestnut breast-band joining on the shoulders, and scarlet bill, are quite unique and unmistakable. Even the yearlings, in which there is no chestnut tint, and whose beaks are merely flesh-colour like the feet, are quite unlike any other duck. In size this bird is a little less than the ruddy sheldrake or Brahminy duck, being about as large as the mallard or spotted-bill, though much higher on the legs.
It walks and runs well and gracefully like its ruddy relative, and also swims high in the stern; the male floats particularly high in the water and looks decidedly bigger than the female, but there is practically no difference in plumage, although the drake's is richer in its hues. He has, however, a knob at the base of the bill in the breeding-season, and some trace of this is always visible in fully adult birds.
The note differs greatly in the two sexes in this sheldrake, being in the male a low whistle, while the female's is loud and harsh, something between a quack and a bark. Though perhaps more often seen ashore than afloat, this duck is more of a water bird than the Brahminy, and can at a pinch dive well and go some distance under water. It is wary and hard to shoot, and as food it is one of the very worst of ducks, and indeed is not usually regarded as eatable. It feeds chiefly on small animal life, especially minute shell-fish, but also eats grass. All across the Old World it is a well-known bird in the north by the sea and lakes, but the bird known as sheldrake in the United States is our red-breasted merganser; the prefix " shel " means pied, and no doubt was originally common to both species, as showing much white.