Gregarious in winter over large parts of the U.S., the abundant Lesser Scaup breeds primarily in boreal forest regions of Canada. Lesser Scaup migrate late in the season, when lakes freeze, and travel nocturnally in flocks.
Nests of Lesser Scaup are sometimes parasitized by other duck species, and may contain Redhead, Canvasback, Ruddy Duck, or other duck eggs. The scaup appear to be unaffected by this, and raise the same number of their own young whether their nest was parasitized or not.
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Description of the Lesser Scaup
BREEDING MALE
The Lesser Scaup is a diving duck slightly smaller than a Redhead, and has a bluish-gray bill with a small black tip, and a crown that is peaked at the rear.
Males have white flanks, gray upperparts, and a purplish-black head. Length: 16 in. Wingspan: 25 in.

Female in the middle, other 2 images are males. Photographs © Glenn Bartley.
Female
Females have brownish flanks and upperparts, a brown head, and a white patch at the base of the bill.
Seasonal change in appearance
Males in nonbreeding plumage are similar but browner.
Juvenile
The immature Lesser Scaup is similar to the adult female.
Habitat
Lesser Scaup inhabit lakes, marshes, and estuaries.
Diet
Lesser Scaup primarily eat mollusks, insects, and plant material.
Behavior
The Lesser Scaup dives in shallow water to forage, or dabbles in shallow water.
Range
Lesser Scaup occur throughout most of the U.S. and Canada, breeding in northwestern portions of the U.S. north to Alaska, and wintering across a broad swath of the central and southern U.S., as well as the Pacific, Gulf, and Atlantic Coasts. The population is generally large and stable.
More information:
Bent Life History
Visit the Bent Life History for extensive additional information on the Lesser Scaup.
Wing Shape
The shape of a bird’s wing is often an indication of its habits and behavior. Fast flying birds have long, pointed wings. Soaring birds have long, broad wings. Different songbirds will have a slightly different wing shape. Some species look so much alike (Empidonax flycatchers) that scientists sometimes use the length of specific feathers to confirm a species’ identification.
Wing images from the University of Puget Sound, Slater Museum of Natural History
Fun Facts
The Lesser Scaup can occur in very large, single-species flocks during the winter.
The Lesser Scaup is one of the latest migrating ducks in the spring, and form pair bonds during migration.
Vocalizations
Female Lesser Scaup give a bark, while males produce a whistle.
Similar Species
Greater Scaup
Greater Scaup are larger, with males having a slightly greenish gloss to the head, and both sexes having a more rounded crown.
Ring-necked Duck
Ring-necked Ducks have a white band near the end of the bill.
Nesting
The Lesser Scaup’s nest is a depression lined with grasses and down, and placed on land or an island.
Number: Usually lay 7-9 eggs.
Color: Olive or buff.
Incubation and fledging:
The young hatch at about 21-27 days and leave the nest soon after hatching, but cannot fly for about 7-8 weeks.
Bent Life History of the Lesser Scaup
Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.
Bent Life History for the Lesser Scaup – the common name and sub-species reflect the nomenclature in use at the time the description was written.
FULIX AFFINIS (Eyton)
Unlike the larger scaup duck, this species is distinctly an American duck, but of wider distribution on this continent. It is more essentially an inland species, showing a decided preference for the smaller lakes, ponds, marshes, and streams, whereas its larger relative seems to prefer the larger lakes in the interior and the seacoast in winter. Its breeding range is more extensive and its center of abundance during the breeding season is much farther south, its chief breeding grounds being in the prairie regions of central Canada and the Northern States. Though differing in distribution and in their haunts, the two species are closely related and much alike in appearance, so much so that so good an observer as Audubon failed to distinguish them; nearly all that he wrote about them evidently referred to the lesser scaup, with which he was most familiar, and he criticised Wilson for some of his remarks which evidently referred to the greater scaup. Adult males of the two species are, of course, easily recognized, but the females and young birds are so much alike and vary so much in size that they are often confused. Rev. W. F. Henninger writes me that a series of Fulix aftinis which he has examined measure up to the minimum measurements given for Fulix mania and that the males show both purple and green reflections on the head; this suggests the possibility of intergradation between the two species.
Spring: The lesser scaup duck is not one of the earliest migrants, but it begins to move northward from its winter home soon after the melting ice and snow begin to indicate the coming of spring. On its migration it follows the courses of the larger streams and rivers, but when it settles down to feed it soon spreads out into the sloughs, marshes and shallow ponds. Prof. Lynds Jones (1909) says that, m Ohio, “it literally swarms in the marshes during late March and the most of April, where feeding companies cover large areas of the open waters of the marshes.” Where spring shooting is allowed it flies wildly about, seeking refuge on the open lakes beyond range, but on certain reservoirs where it is not molested it appreciates the security and becomes very tame. In such places a few birds linger well into the summer and some apparently remain to breed.
Courtship: Very little has been published about the courtship of this species, but Audubon (1840) makes the following brief reference to it:
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.
Dr. Alexander Wetmore (1920) gives the following account of it:
A pair rested in open water in front of me when suddenly the female began to swim back and forth with the head erect, frequently jerking the tip of her bill up while the male drew his head in on his breast and lowered his crest, giving his crown a curious flattened appearance. The female turned alternately toward and away from the male, sometimes biting gently at him, while occasionally he responded by nip- ping at her with open mouth. At short intervals she dove toward him, barely sliding under his breast, and emerged at once only a few feet away, or at times advanced toward him brushing against him and then turning away. A second male that tried to approach was driven away by quick rushes though the female paid no attention to him. She continued her diving and finally at intervals the male began to dive with her, both emerging at once. As the display continued he joined her under the water more and more frequently and finally both remained below the surface for over 30 seconds where copulation apparently took place. When they emerged the female swain away for a short distance with the male following her. Frequently during these displays the female gave a peculiar rattling, purring call like kaetdi-h-h-h-h while the males whistled in a low tone.
Nesting: Although they arrive on their breeding grounds fairly early, they are very deliberate about nesting preparations and are among the later breeders. All through the extensive western prairies these little ducks may be seen, throughout May and the first half of June, swimming about in pairs in the little marshy creeks, sloughs, and small ponds; they are apparently mated when they arrive and seem to enjoy a protracted honeymoon. In the. Devils Lake region in North Dakota we found the lesser scaup duck nesting abundantly in 1901 and examined a large number of nests. On the small islands in Stump Lake, now set apart as a reservation, we found 16 nests of this species in one day, June 15, and all of the eggs proved to be fresh or nearly so. The nests were almost invariably concealed in the taller prairie grass, but some nests were located under small rosebushes and one was placed against the side of a small rock surrounded by tall grass, hut in a rather open situation. The nest consisted of a hollow scooped in the ground, profusely lined with very dark down mingled with a little dry grass and occasionally a white feather from the breast of the bird. The females seemed to be very close sitters; we always flushed the bird within 10 feet of us or less; but when once flushed they seemed to show no further interest in our proceedings. The males apparently desert the females after incubation has begun and flock by themselves in the sloughs or small ponds. Lesser scaup ducks occasionally lay in other duck’s nests; we found one of their eggs in a gadwall’s nest and one in a white-winged scoter’s nest; but we found no evidence that other ducks ever lay in the scaup’s nests.
In southwestern Saskatchewan the les~er scaup duck was not so abundant as in North Dakota, but still quite common; we found 6 nests in situations similar to those described above; three of these were on that wonderful island in Crane Lake, more fully described under the gadwall. In Manitoba, about Lake Winnipegosis, we found a few nests one of which was in a different situation from any other we had seen; it was built like a canvasback’s nest in the water near the edge of a clump of buirushes (Sc irpus lacust r~s) , but it contained the dark down and the characteristic eggs of the lesser scaup. Nests have been reported by other observers in such situations, but the nest is usually placed on dry ground. MacFarlane (1891) found over a dozen nests of this species near the northern limit of the wooded country on the east side of the Anderson River, of which he says:
They were usually found in the midst of a swamp: a mere hole or depression in the center of a tuft of turf or tussock of grass, lined with more or less down, feathers, and hay.
Dr. Joseph Grinnell (1909) refers to a nest found by Mr. Littlejolin on an island in Glacier Bay, Alaska; it was at the edge of a small pond “placed within a heavy growth of grass about a foot from the water’s edge, and consisted of grass stems lined with a little down from the parent’s breast.”
The down in the lesser scaup duck’s nest is indistinguishable from that of its largest relative, “clove brown” or “hone brown” in color, with inconspicuous lighter centers. The small breast feathers in it are white or grayish white.
Eggs: The lesser scaup duck lays from 6 to 15 eggs, but the com- monest numbers run from 9 to 12. The eggs are like those of the larger scaup duck but they are decidedly smaller. The shape varies from elliptical ovate to nearly oval. The shell is smooth and slightly glossy. The color varies from “ecru olive” or “dark olive buff” in the darkest eggs to “deep olive buff” in the lightest eggs. When seen in the field the deep cafi au lait color of all the scaup duck’s eggs is distinctive and unmistakable, but in cabinet sets it has usu- ally faded more or less and is not so conspicuous. It is always much easier to identify ducks’ eggs in the field than in collections, for there is usually something about the eggs, the nest, or the bird which is distinctive. The measurements of 88 eggs, in the United States National Museum and the writer’s collections, average 57.1 by 39.7 millimeters; the eggs showing the four extremes measure 81.5 by 38, 59 by 42.5, and 50 by 35.5 millimeters.
Young: Incubation is performed by the female alone and prob- ably lasts from three to four weeks. When the young are hatched she leads them to the nearest water, which is usually not far distant, and teaches them how to escape from their numerous enemies and how to catch their insect food. While engaged in rearing and study- ing young ducks in Manitoba we employed Indians to catch the small young of this and some other species which we did not succeed in hatching in the incubators. Mr. Hersey’s notes describe their methods as follows:
A brood of lesser scaup found on a small pond acted very differently from young golden-eyes. Instead of separating they drew close together and swam back and forth a few feet. The Indians plunge into the pond, clothes and all and drive the brood toward our end. They swim along quietly and as they near the end of the pond the Indians close in until they are within a few feet of the birds. Then sud- denly the birds begin to dive, each one swimming under water past the men and coming up well out toward the middle of the pond. If the water is clear the Indians will watch the young bird swimming and catch them under water, but if muddy, they all get safely by and then the whole performance is repeated.
It often happens when a brood dives in this way, that one or more birds get sepa- rated from the rest. The single birds are picked out and captured first, while the rest of the brood wait at the other end of the pond. It is no easy matter to catch one of these youngsters. When he realizes he is being chased he makes every effort to get back to his brothers and sisters, pattering along the surface much faster than a man can move through the water. However, they usually head him off and he then returns to diving. After a while he gets tired and diving once more swims under water until close to the shore when he crawls into the grass. Once on l’~nd he loses no time but pushes his way rapidly through the grass. Unless his pursuer is quick he will yet make his escape, but the Indians aware of this habit watch the tops of the grass closely, following his movements hy the slight waving and soon overtake him.
Plumages: The downy young is darkly and richly colored. The upper parts are dark, lustrous “mummy brown” or “sepia,” shaded with “brownish olive”; these colors are darkest and most lustrous on the posterior half of the back and lightest on the shoulders; the dark colors cover the upper half of the head and neck, the back and the flanks, fading off gradually into a dusky band around the lower neck and encroaching on the ventral region posteriorly. The color of the under parts, which covers the lower half of the head, throat, breast, and belly, varies in different individuals; in some it runs from “olive ocher” to “primrose yellow,” but in most specimens from “chamois” to “cream buff”; these colors are brightest and richest on the cheeks and on the breast. The markings on the head are usually indistinct, but a superciliary buff stripe, a loral dusky stripe and a postocular dusky stripe are discernible in the majority of a series of 11 specimens in my collection. There is also an indistinct yellowish spot on each scapular region, but none on the rump. The colors become duller and lighter as the duckling grows older.
So far as I can judge from the study of available material, the sequence of plumages to maturity and the seasonal molts of adults are practically the same as in the greater scaup duck. Young birds do not breed during their first spring and become practically adult in plumage after their first complete summer molt, or when from 14 to 16 months old. The eclipse plumage of the adult male is only partial and not conspicuous. The adult female seems to have a distinet breeding plumage, which is much browner than the winter plumage and in which the white face wholly or partially disappears.
Food: The feeding habits of the lesser scaup are much like those of the greater scaup, except that the smaller species is confined almost wholly to fresh water. Mr. Vernon Bailey (1902) writes:
Like all of the genus, the lesser scaups are great divers and keep much in the open lakes, often in large flocks, where they dive for food, or sleep and rest on the water in comparative safety. They can not resist the temptation of the rice lakes, however, and swarm into them by thousands to fatten on the delicious grain, which they glean from the mud bottoms after it has been threshed out by the wind and the wings of myriads of coots and rails. While they eat, the hunters lie hidden in the tall rice and on the ridges which they must pass in going from lake to lake, and in spite of their bullet-like flight the sadly thinned flocks show the penalty they have paid for leaving the open water.
Their animal food consists of small fry and fish spawn, tadpoles, pond snails and other small mollusks, worms, crawfish, water insects, and larvae. They also consume a variety of vegetable food among which Dr. F. Henry Yorke (1899) has identified all the plants men- tioned under the preceding species. The stomachs of this species, taken by Dr. J. C. Phillips (1911) in Massachusetts, contained “seeds of burreed, bayberry, and saw grass (Ciladium effu8um), and snails (Lunatia hews) and ants.”
Behavior: The lesser scaup like its larger relative, is an expert diver and can remain under water for a long time, grubbing on the bottom for its food. Like many of the best divers, its large and powerful feet enable it to swim rapidly beneath the surface without the use of its wings, which are held tightly closed. It swims away so rapidly under water when wounded that it is useless to pursue it; it is said by gunners to cling to the weeds or rocks on the bottom until dead; it seems more likely that in most cases it swims away to some place where it can hide or that it skulks away with only its bill above water; Mr. W. E. Clyde Todd~ (1904), however has published the following note from Mr. Samuel E. Bacon:
I once wounded a duck of this species in shallow water and, wading out to where I saw it last, I found it holding to a strong weed by its bill, 2 or 3 feet below the surface, stone dead.
Audubon (1840) writes:
The scaup duck seems to float less lightly than it really does, its body being com- paratively flat. It moves fast, frequently sipping the water, as if to ascertain whether its favorite food be in it. Then turning i.$s 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 a considerable distance, watches every movement of the intruder, and finally either returns to its former place or flies away.
On the wing, as well as on the water, the lesser scaup duck is a very lively, nervous, and restless bird; its flight is very swift and often erratic with frequent unexpected twists and turns, which make it a difficult bird for the sportsman to hit; but it often flies in large flocks, closely bunched, or with a broad front of many birds abreast, which gives the gunner an opportunity for an effective raking shot. When much disturbed by shooting these ducks fly about from one lake to another high in the air twisting and turning in a most erratic manner and finally darting down almost vertically, making the air whistle with their wings. Audubon (1840) says:
When these birds are traveling, 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, some- times in a continuous line. When disturbed, they fly straight forward for a while, with less velocity than when traveling, 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.
Fall: The fall migration starts rather late with this species, as it is one of the last to leave its northern breeding grounds, and it pro- ceeds southward in a leisurely manner in advance of the frost line. The migration route is practically a reversal of the route traversed in the spring, mainly in the interior, over the sloughs, marshs, lakes, and rivers most frequented by gunners. Constant persecution by sportsmen keeps these little ducks on the move and they have little time to rest and feed, except at night on the larger lakes. They decoy readily and many are shot over live or wooden decoys from blinds made in the rushes near their feeding grounds; they are killed by ambushed gunners on their fly ways between the marshes and the lakes where they roost; and they are hunted out of the cover where they feed in the sloughs of the North and the rice fields of the South. They are safe only in the center of some large body of water.
Mr. Todd (1904) quotes another interesting note from Mr. Bacon, describing the departure of these ducks from Lake Erie as follows:
On one occasion I saw, as I believed, all the lesser scaups in this neighborhood start for the south. The bay had frozen over a few nights before, and on this particu- lar afternoon a large flock of these ducks kept circling over the lake, sometimes high in the air, again dropping swiftly to the surface and skimming along for a mile or so. Finally having evidently gathered into one flock all the birds of the vicinity, they rose to a great height and, starting southward, were soon lost to view.
Winter: They are very abundant all winter throughout the south- ern half of the United States, where they find some safe havens of rest. Large numbers winter on the Indian River in Florida and on the lakes in the interior of that State; on Lake Worth they are very abundant and so tame that they have learned to feed almost out of the hands of the winter tourists. On the Louisiana coast they are the commonest ducks and they soon learn to appreciate the security which they find on the protected reservations. It must be a relief to them to find such a wild fowl paradise alter running the gauntlet of shooting grounds and sportsmen’s clubs.
DISTRIBUTION
Breeding range: Northern interior of North America. East to the west coast of Hudson Bay (Churchill) and southeastern Ontario (Lake Temiskaming). South to northern Ohio (Lake, Lorain, and Sandusky Counties), southern Wisconsin (Lake Koshkonong), south- eastern Iowa (Keokuk), possibly northern Nebraska (Cherry County), and northeastern Colorado (Barr Lake, few). West to north- western Montana (Teton County), central British Columbia (Ques- nelle Lake and Lao la Hache), and the coast of southern Alaska (Glacier Bay). Has bred casually near San Francisco, California. North to central Alaska (Yukon River) and the northern limit of timber in northern Canada (Mackenzie and Anderson River regions). Breeding records east of Hudson Bay probably refer to mania, and perhaps some of the northern records do.
Winter range: Southern North and Central America. East to the Atlantic coast of United States, the Bahamas, and the Lesser Antilles (St. Thomas, St. Lucia, Trinidad, etc.). South to Panama. West to the Pacific coast of Central America and United States. North to southern British Columbia (Vancouver and Okanogan Lake), southeastern Arizona (San Pedro River), northeastern Colorado (Barr Lake), northeastern Arkansas (Big Lake), southern Illinois, and eastern Maryland (Chesapeake Bay); rarely as far north as Long Island and Massachusetts (Boston).
Spring migration: Early dates of arrival: Iowa, Keokuk, February 21; Minnesota, Heron Lake, March 5; Michigan, southern, March 11; Alberta, Stony Plain, April 19; Mackenzie, Fort Simpson, May 24. Average dates of arrival: Colorado, Loveland, March 12; Iowa, cen- tral, March 21; Minnesota, Heron Lake, March 22; Ohio, Oberlin, March 24; New York, Cayuga Lake, April 1; Illinois, Chicago, April 6; Ontario, Ottawa, April 26; Manitoba, Raeburn, April 9. Late dates of departure: Panama, March 25; Lower California, San Martin, April 23: Porto Rico, Culebra Island, April 21; Florida, Wakulla County, May 23; New York, Cayuga Lake, June 24.
Fall migration: Early dates of arrival: Ontario, Ottawa, October 12; New York, Cayuga Lake, October 1; Virginia, Alexandria, Sep- tember 25; Florida, Wakulla County, October 18; Panama, November 25. Average dates of departure: Ontario, Ottawa, November 11; New York, Cayuga Lake, November 15; Manitoba, southern, No- vember 18; Minnesota, southern, November 13; Iowa, Keokuk, De- cember 2. Late dates of departure: Quebec, Montreal, November 12; Ontario, Ottawa, November 21; Illinois, Chicago, December 22.
Casual records: Accidental in Bermuda (December 19, 1846, January 8, 1849, and February 25, 1876). Rare in migration to Newfoundland and Nova Scotia. Accidental in Greenland (Egedes- ininde).
Egg dates: Alaska and Arctic America: Eighteen records, June 17 to July 18; nine records, June 22 to July 5. Manitoba, Saskatchewan and Alberta: Thirteen records, May 20 to July 14; seven records, June 10 to July 3. Minnesota and North Dakota; Eighteen records, May 1 to July 10; nine records, June 12 to 25.