The opinion, derived from WILSON’S account of the Scaup Duck, that it is met with only along our sea coasts, in bays, or in the mouths of rivers, as far as the tide extends, is incorrect. Had WILSON resided in the Western Country, or seen our large lakes and broad rivers during late autumn, winter, or early spring, he would have had ample opportunities of observing thousands of this species, on the Ohio, the Missouri, and the Mississippi, from Pittsburg to New Orleans. I have shot a good number of Scaup Ducks on all these rivers, where I have observed them to arrive early in October, and whence they depart between the 1st of March and the middle of April. I have not, however, seen any in small creeks, lagoons, or ponds. When they arrive on the western waters, they are seen in flocks of from fifteen to twenty individuals; but in a few weeks these flocks are joined by others, for which reason the species is named in Kentucky the “Flocking Fowl.” They are, however, seldom seen close together while on the water, and they rarely associate with other birds.

The Scaup Duck seems to float less lightly than it really does, its body being comparatively flat. It moves fast, frequently sipping the water, as if to ascertain whether its favourite food be in it. Then turning its head and glancing on either side to assure itself of security, down it dives with all the agility of a Merganser, and remains a considerable time below. On emerging, it shakes its head, raises the hind part of its body, opens its short and rather curved wings, after a few flaps replaces them, and again dives in search of food. Should any person appear when it emerges, it swims off to a considerable distance, watches every movement of the intruder, and finally either returns to its former place, or flies away.

These birds are fond of large eddies below projecting points of land, but frequently dive in search of food at a considerable distance from them. When in eddies they may be approached and shot with less difficulty than when in any other situation. If wounded only, they are not easily secured; in fact, you need not go after them, for by diving, fluttering along the surface, and cutting backward and forward, they generally elude pursuit. Between Louisville and Shippingport, on the Kentucky side of the Ohio, the shores are from ten to fifteen feet high, and rather abrupt when the waters are at their ordinary level. The Scaup Ducks are fond of diving for food along this place, and there, by coming directly upon them unseen, till you are almost over them, you may have the very best opportunities of procuring them. They are not worth shooting, however, unless for sport or examination, for their flesh is generally tough and rather fishy in flavour. Indeed I know none, excepting what is called an Epicure, who could relish a Scaup Duck.
 
They appear to experience some difficulty in getting on wing, and assist themselves on all occasions, either by meeting the current or fronting the wind, while they also use their broad feet as helps. When danger is near, they frequently, however, prefer diving, which they find as effectual a means of security as flying. As they usually feed at some distance from each other, it is amusing to see them go off, as they emerge from the water in succession, and to watch them when they collect again, and when, after flying for a long time in circles, now high then low over the water, they all realight. These habits, and the toughness of their sinewy bodies, render it rather difficult to shoot them. Although flat-billed, they dive to a considerable depth, and when they have reached the bottom, no doubt furrow the mud, in the manner of the Shoveller (Anas clypeata), although the latter performs this action while floating, on the surface, with its head and neck alone submersed, as it swims over the shallows.

The food of the Scaup Duck I have found to consist of small fry, crayfishes, and a mixture of such grasses as here and there grow along the beds of our rivers. I never found any portions of testaceous mollusca in the gizzards of those obtained on our western waters, although even there they might meet with abundance of these animals.

When these birds are travelling, their flight is steady, rather laborious, but greatly protracted. The whistling of their wings is heard at a considerable distance when they are passing over head. At this time they usually move in a broad front, sometimes in a continuous line. When disturbed, they fly straight forward for awhile, with less velocity than when travelling, and, if within proper distance, are easily shot. At times their notes are shrill, but at others hoarse and guttural. They are, however, rarely heard during the day, and indeed, like many other species, these birds are partly nocturnal.

At the approach of spring the Drakes pay their addresses to the females, before they set out on their journey. At that period the males become more active and lively, bowing their heads, opening their broad bills, and uttering a kind of quack, which to the listener seems produced by wind in their stomach, but notwithstanding, appears to delight their chosen females.

The Scaup Duck varies materially as to size at different ages. Some wounded individuals which I kept, and which were birds of the first year, were much larger and heavier at the end of a year; and I agree with my learned friend NUTTALL, that specimens may be procured measuring from sixteen and a half to eighteen, nineteen, or twenty inches in length.

On the Atlantic coast I have met with this species from the Gulf of Mexico to the Bay of Fundy, and my friend THOMAS MACCULLOCH has told me that they are not unfrequent at Pictou in Nova Scotia. Farther north I saw none; and their breeding places are yet unknown to me.