It is not surprising that this, the genuine golden-eye, should be often mixed up by Indian sportsmen with the tufted pochard, since both are pied diving-ducks with yellow eyes ; but in reality they are quite easily distinguishable even at a distance, for in the real golden-eyed drake the breast is white as well as the flanks, and there is a great white patch on the face. Even the female, whose breast is grey like her back, has a white neck sharply contrasted with her dark-brown head, and so is well distinguished from the female tufted duck, whose neck is dark continuously with the head and breast.
In flight the golden-eye is distinguishable by sound more than any other duck, the very loud and clear whistle made by the wings, which have no white on the end-quills like those of the tufted pochard, being a most marked characteristic of the species, and often giving it a special name, such as "rattle-wing" and " whistler."
There is a good deal of difference in size between the sexes of this species, the drake weighing two pounds or more, sometimes nearly three, while the duck runs more than half a pound less, and looks conspicuously smaller when both are together. Young males are very like females, but the old male in undress may be distinguished, not only by his much greater size, but by having more white on the wing.
The golden-eye has a bushy-looking head and a very narrow, short, high-based bill ; the tail is also very characteristic, being longer than ducks' tails usually are. Often, however, it is not to be seen as the birds are swimming, being allowed to trail in the water, but sometimes they float with tail well out of the water, when the length becomes noticeable. On land, where they spend but little time, they stand more erect than most ducks.
Golden-eyes in India only appear as uncommon winter visitors, as a rule ; but in the valley of the Indus at one end of our area and the Irrawaddy at the other, they seem to occur regularly, and are also common in the Lakhimpur district, frequenting hill-streams like the mergansers, to which, rather than to the ordinary diving-ducks, they are related. Indeed, this species has been known to produce hybrids with the smew in the wild state, and, like that bird, it breeds in holes in trees in the northern forests.
The golden-eye, however, is found all round the world, not confined to the Eastern Hemisphere. It goes in winter either singly or in flocks, and Mr. Baker has shot one consorting with gadwall, and noticed that it flew well with them ; in fact, this is the most active flyer of all the diving-ducks except perhaps the smew. In the water it is a fine performer, and catches fish like the mergansers, also feeding on shell-fish and water-weeds. In diving it seems to slip under, as it were, more neatly than the pochards, the fanning- out of the tail being conspicuous as it disappears ; and it has been noticed that when a flock are below and an alarm comes from above, all the diving individuals will rise and make off out of shot, not coming up and giving the enemy a chance as the pochards will do. The general character of the bird is, in fact, one of extreme wariness, and in this respect it is a merganser rather than a true or typical duck. The alarm-note is given by Mr. Baker as " a loud squawk," but this is no doubt uttered by the female only ; the male's note is different, as is the case with the male mergansers, which this bird resembles in having a large angular bulb in the windpipe. A peculiarity of its beak, unique among Indian birds, should be noticed; the nostrils are very near the tip, further forward even than in a goose. As an article of food this bird is highly fishy; but its green eggs are esteemed by the inhabitants of the north, who put up boxes for it to lay in.