With a distribution extending to several continents, the Fulvous Whistling-Duck is nonetheless limited to a few of the southernmost portions of the U.S. Some of these populations are migratory, with movements taking place at night. Fulvous Whistling-Duck pairs are thought to mate for life.
Much remains to be learned about the breeding ecology of the Fulvous Whistling-Duck. While the breeding season is long and it is expected that failed nests are replaced, this needs confirmation. While year-old birds are capable of breeding, it is likewise not known how frequently they actually do breed.
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Description of the Fulvous Whistling-Duck
The Fulvous Whistling-Duck is a tall, long-necked duck with a black bill, reddish-brown underparts, a blackish back with tawny-edged feathers, and a dark stripe along the hindneck. Length: 19 in. Wingspan: 26 in.
Hindneck stripe usually continuous.
Seasonal change in appearance
Similar to adults but paler.
Forages by dabbling and occasionally by diving, as well as grazing on land.
Resident in southern Florida and Texas, and a breeder along most of the Texas and Louisiana coastline and very locally in southern California. It is also resident south to South America, and occurs in Africa and Asia.
Few ducks are as widespread worldwide as Fulvous Whistling-Ducks.
Fulvous Whistling-Ducks are not territorial, and defend only the nest and a small feeding zone.
A squealing, two-syllable whistle is given.
- Unique appearance. Could only be confused with the Black-belied Whistling Duck.Black-bellied Whistling-Duck
The Black-bellied Whistling-Duck, as the name implies, has a black belly, orange bill and large white wing patch.
The nest is a bowl of grass and aquatic vegetation placed on the ground.
Incubation and fledging:
– Young hatch at 24-26 days.
– Young fledge (leave the nest) shortly after hatching but remain with the adults for some time.
Bent Life History of the Fulvous Whistling-Duck
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 Fulvous Whistling-Duck – the common name and sub-species reflect the nomenclature in use at the time the description was written.
DENDROCYGNA BICOLOR (Vieillot)
Messrs. Grinnell, Bryant, and Storer (1918) introduce this species in a few well-chosen words as follows:
The term tree duck, as applied to the fulvous tree duck, seems to be an almost complete misnomer for the bird. As regards structure this species seems to be more closely related to the geese than to the ducks, and, at least in California, it seldom nests in trees but chooses the extensive tule marshes of our interior valleys. Birds apparently belonging to the same species of tree duck that occurs in this State are found in South America, in southern Uruguay and Argentina, and also in South Africa and in India: a very striking case of what is kaoxvn as interrupted or discontinuous distribution. In North America the chief breeding ground of the species is in Mexico, but a considerable number of birds breed in the southwestern United States. The latter contingent is migratory, moving south for the winter season.
Spring: Col. A. J. Grayson, in his notes quoted by Mr. George N. Lawrence (1874), says:
Although its geographical range is confined within the limits of the Tropics, yet this species has its seasons of periodical migrations from one part of the country to the other; during the month of April their well-known and peculiar whistle may be heard nightly as they are passing over Mazatlan in apparently large flocks, going northward. At first this phenomenon puzzled me not a little, as I well knew that they are not often found far north of the Tropics, except an occasional straggler. But I was at length enlightened as to their point of destination by frequent inquiries of the natives, I was satisfied that they went no farther north than the Mayo and Yaqui Rivers, in Sonora, and the adjacent lakes and lagoons, where they breed. Some, however, remain and breed in the State of Sinalon, and the adjoining localities.
Referring to the migration in South America, W. H. Hudson (1920) writes:
This duck, the well-known Pate stEven (whistling duck) of the eastern Argentine country, is found abundantly along the Plata and the great streams flowing into it, and northwards to Paraguay. Along this great water~vay it is to some extent a migratory species, appearing in spring in Buenos Aires in very large numbers, to breed in the littoral marshes and also on the pampas. They migrate principally by night, and do not fly in long trains and phalanxes like other ducks, but in a cloud; and when they migrate in spring and autumn the shrill confused clangor of their many voices is heard from the darkness overhead by dwellers in the Argentine capital ; for the ducks, following the eastern shore of the sealike river, pass over that city on their journey.
Nesting: One of the best accounts of the nesting habits of the fulvous tree duck in California is given by A. Xl. Shields (1899), as follows Starting early next morning to search a different locality, the place selected was an extensive strip of high grass growing in the damp swampy ground and sometimes in several inches of water. The grass was from 2 to 3 feet high, of a variety commonly known as “sword’ or “wire” grass, and covered an area of perhaps 100 acres of low land between the deep water and the higher ground a few hundred yards back. Just as we were alighting from the wagon on the edge of the swampy area I saw a fulvous tree duck flying from Ihe swamp. After a few circles she dropped down among the dense grass not 300 yards distant, and I, not stopping to put on my wading boots but keeping my eye on the spot where she had settled, quickly approached and when withIn a few yards I was delightfully shocked by a flutter of wings and the sight of the old bird rising and winging a hasty retreat. I reached the nest and what a thrill at the sight, there in the midst of a little vacant square of 4 or 5 feet was a beautifully built nest, composed entirely of grass, about 6 inches in height and containing 19 beautiful white eggs. I immediately saw by comparison that my surmise as to the identity of the strange parasite eggs found the day before was correct.
The nest was situated in the center of a little open spot in the grass; the open area had evidently been created by the bird in her quest for building material, for she bad proceeded to pull up or break off the grass immediately adjacent as her nest grew higher and larger, until the nest finally occupied a position in broad daylight as it were, although it is not improbable that when the spot was selected it was well hidden by overhanging and surrounding grass. I was not long in securing this nest and eggs, after which we began a systematic search through the high grass and in a short time I had found my ~econd ncst, constructed similarly to the first but a little better hidden, being under an overhanging bunch of grass which furnished a slight covering. This nest contained 30 eggs, deposited in a double layer; and if the first set of 19 was a surprise, what shall I say of this?
Dr. Harold C. Bryant (1914) describes other nests, similarly located, as follows:
One of our most interesting finds was a nest of the fulvous tree duck, discovered on May 12, 1914. The nest was situated on a hummock in the middle of a marsh between two ponds. The nest was a well-woven one of dry sedges lilaced about 6 Inches above tile ground in a tall clump of sedge and weeds. The cavity was about 5 inches deep and in it lay 12 ashy white eggs. A few days later the nest was raided by some predacious animal and all the eggs destroyed. On May 18 we discovered a second nest in the same swamp. This one was built about 6 inches above the water in a small clump of sedge and contained but 4 eggs. The sedges were arched over the cavity in such a way as to conceal it effectively. Two days later when we visited this nest we found it also raided. The only other nest of this species noted was a new one found on June 23. No attempt had been made at special construction of a nest, the two eggs simply lying in a crushed-down place among tall sedges.
The method of nesting described above seems to be the method regularly followed in California. I have two sets of fulvous tree duck’s eggs in my collection from Merced County, California; one nest is described as made of grass and small tules, lined with fine grass and a little down, and placed on the ground among high grass in a swamp; the other nest was made of grass and tules and was placed in a clump of grass and ttmles in a ditch with 2½ feet of water under it; there were 29 eggs in the latter nest, 10 of which were in the upper layer.
That this duck probably does nest occasionally in trees in California, as it certainly does elsewhere, is suggested by the following observation by W. Otto Emerson, published by Mr. Shields (1899), in his paper referred to above:
On May 23, 18S2, while collecting with William C. Flint at Lillies ranch near Tulare Lake I noticed a fulvous tree duck sitting in the entrance hole of a large white oak near one of the ditches, but it was out of the question to reach It. Again on May 26 another was located sitting on the edges of a hole high up In a white oak.
Mr. D. B. Burrows found this species nesting in hollow trees, at heights varying from 4 to 30 feet, in the valley of the lower Rio Grande, near Roma, Texas. lie says in his notes:
The fulvous tree duck is a common species in some localities along the Rio Grande River. In the breeding season ibo birds are frequently seen singly, perched in large trees iii the heavily timbered bottom lands.
I secured two sets of their eggs, one of which contained 14 and the other 11 eggs. Both of these nests were found by Mexicans, and one of them I visited and examined. This nest was a natural cavity in the large trunk of a mesquite tree and about 4 feet from the ground the cavity was about 2 feet in depth and the eggs, 11 in number, were placed on rotten chips at the bottom.
The eggs are deposited at a warm time of the year, and I am informed by the Mexicans that the birds are in the habit of leaving the nests for the greater part of tIme day, the heat of the sun continuing their incubation. but they return and remain upon the nest during the night and the cool part of the morning, Flow true this is I am not able to say, as I had no opportunity of watching them, hut it seems quite reasonable. The nest was more than half a mile from the Rio Grande River, in a broad mesquite bottom.
Eggs: Either the fulvous tree duck lays an extraordinary number of eggs or several females lay in the same nest. Mr. Shields (1899) says:
We subsequently found about a dozen nests, all similarly situated, and most of them containing from 17 to 28, 30, 31, and 82 eggs. The smallest set found was of 9 and another of 11 eggs, both evidently being incomplete, as the nests were not finished and incubation had not commenced.
Authentic sets of as many as 36 eggs are in existence and probably much larger numbers have been found according to F. S. Barnhart (1901), who writes:
From time to time since 1895 pothunters have told wonderful stories of finding large numbers of eggs piled up on bunches of dead grass and on small knolls that rose above the water in the swamps. The number of eggs in these nests ranged from 30 to 100 or niore, according to report, aiid in not a few cases the finder has brought the eggs with him in order to prove that what lie said was true.
Probably the large numbers referred to by Mr. Barnhart are surplus eggs laid~ by various individuals and never incubated; and perhaps some of the large sets in collections are the product of more than one female. Evidently the fulvous tree duck is careless in its laying habits, for Mr. Shields (1899) speaks of finding eggs of this species in the nests of the redhead and the ruddy duck. All of the slough-nesting ducks seem to be careless about laying in each other’s nests and to have the habit of using “dumping nests” in which large numbers of eggs are laid and forgotten.
In shape the eggs are bluntly ovate, short ovate, or oval. The shell is usually smooth and without gloss, but in many specimens, probably those that have been incubated, the shell is quite glossy and minutely pitted. The color varies from white to huffy white, but the eggs are often much stained with deep shades of buff. The measurements of 212 eggs, in various collections, average 53.4 by 40.7 millimeters; the eggs showing the four extremes measure 59.9 by 40.4, 52.5 by 44.03, 49.1 by 39.7 and 51.7 Lv 37.6 millimeters.
Plumages: The downy young of the fulvous tree duck is described by Grinnell, Bryant, and Storer (1918) as follows:
Top of head clove brown; chin, throat, and sides of head dull white, a streak of the same color extending around back of head oa each side and meeting its fellow on hind head; a short, dull white streak on each side of head from side of bill to above eye; bill (dried) dusky brown with prominent yellowish nail; hind neck clove brown, a streak of same color invading side of head below streak of white which encircles head; rest of upper surface of body uniform bister brown; whole under surface of body dull white; feet (dried) grayish yellow.
A series of young birds in my collection, about two-thirds grown, are strikingly like adults, except that the colors are all duller, the brown edgings on the back are narrower, there is less chestnut in the wing coverts, and the upper tail coverts are tipped with brown. I have no data as to subsequent molts and plumages, but suppose that the adult plumage is assumed at the first postnuptial molt when the young bird is a little over a year old.
Food: Mr. Shields (1899) says that these ducks “are equally at home in an alfalfa patch (about dusk) or in a lake of water, and are entirely at home in an oak forest not far from the breeding swamp, where they are said to assemble for the purpose of feeding on acorns.”
Referring to the food of this species, Grinnell, Bryant, and Storer (1918) write:
The fulvous tree duck feeds largely on the seeds of grasses and weeds. In Mexico and Texas it is said to visit the cornfields at night where it finds palatable provender. When feeding in muddy or marshy situations the birds thrust their bills deep in the soft mud on both sides and in front of them as they walk along. The stomach of an individual obtained at Los Banos, Merced County, in May, 1914, and examined by us, contained finely cut up grass and other vegetable matter.
Behavior: The same writers say on this subject:
The fulvous tree duck is more easily approached than many other waterfowl, but nevertheless is often difficult to find as it congregates among the dense tules or far out on the marshy ponds. On occasion a flock has been easily approached and. a number killed at one shot. Sometimes, when tree ducks are surprised on grassy ground, they simply stand rigidly with their heads and long necks straight up in the air, and at a distance look more like stakes than birds. When wounded they are said to escape not only by diving but also by running at great speed and hiding in the grass, and thus often baffle entirely the hunter’s efforts to recover them.
Game: Regarding its status as a game bird, they say:
The flesh of the fulvous tree duck is light colored and juicy, and also free from the rank flavor possessed by sea-faring ducks and geese. On their arrival in California the birds nre fat and eminently fit for the table; but since they are here in greatest numbers during the close season, they lurgely escape the slaughter levied on other wild fowl. The numbers of this species are, at best, small in comparison with many other ducks and geese. They could ill afford a heavy toll hy the hunter during the period of their stay here. Any levy upon them during the actual breeding season would be contrary to all recognized principles of game conservation and humanity. As it is, but a few tree ducks are to be shot each year at the opening of the season, October 15. Those who are anxious to hunt the fulvous tree duck in numbers must go to Mexico, where the birds are to be found regularly in winter and where a certain toll may be levied with safety.
Winter: On the winter habits of the fulvous tree duck in Mexico Mr. Lawrence (1874) quotes Colonel Grayson as follows:
At the conclusion of the rainy season, or the month of October, they make their appearance in the vicinity of Mazatlan, San Bias, and southward, in large flocks; inhabiting the fresh-water ponds and lakes in the coast region, or ticrra calientc, during the entire winter, or dry months, subsisting principally upon the seeds of grass and weeds, and often at night visiting the cornfields for grain. During these months I have found them in the shallow grass-grown ponds in very large numbers, affording excellent sport to the hunter, and a delicious game for the table; their flesh is white, juicy, and, feeding upon grain and seed, is free from the strong or rank flavor of most other ducks; they are rather heavy or bulky and usually fat. They are more easy to approach than our northern species; I have shot as many as 15 with the two discharges of my double-barrel. When only winged they are almost sure to make their escape, which their long and stout legs enable them to do, running and springing with extraordinary agility, and ultimately eluding pursuit by dodging into the grass or nearest thicket; if the water is deep they dive, and as they rise to breathe, having only the head above water, and that concealed among the water plants, they are soon abandoned by the hunter.
Mr. II. B. Conover writes to me, of the haunts of this species in ‘Venezuela, as follows:
The only place we saw this duck was at Lagunillas. Here on a large savannah or swamp we saw thousands of tree ducks, about 5 per cent of which were fulvous and the rest gray breasted. The fulvous tree duck was very much wilder than the other, and when polling through the marsh, would be the first to leave, generally rising 100 to 150 yards away. On the water these birds xvere very easy to distinguish from the gray breasted because of their whitish rump, which showed up plainly. They flocked by themselves, as I never noticed them mixed in with flocks of gray breasted or vice versa. This marsh was a shallow place, I believe not over 3 feet deep in any spot, and consisted of large pieces of open water with patches and islands of high grass on the sides. The open water was covered for the most part with floating aquatic plants somewhat similar to our lily. It wus in those open places, among the floating nquatic plants, that the tree ducks could be seen. This bird was well known to the natives there and went by the name of Linguasa Colorado as against the plain Liaguasa for the gray-breasted tree duck.
Breeding range: Sonthwestern North America, parts of South America, and southern Africa and India. in North America east to Louisiana (Lake Catharine and the Iligolets). South to central Mexico (Jalisco and Valley of Mexico). North to central California (Merced County), central Nevada (Washoe Lake), southern Arizona (Fort Whipple). and eastern Texas (Nueces County). in South America from central Argentina (near Buenos Aires and in Ajo district), northwards to northern Argentina (Tucuman Fort, in Donovan), central Paraguay (Asuncion), and southern Brazil. Occurs in northern South America (Colombia, Venezuela, and British Guiana) ; it probably breeds in these localities and casually on the island of Trinidad.
Winter range: Ificludes the breeding range and extends southwards in Mexico to Guerrero and Chiapas and northwards in California to the Sacramento Valley (Marysville) and Mann County (Inverness).
Migrations: Migratory movements are not well marked, but occur mainly in April and October.
Casual records: Has wandered east to North Carolina (Currituck Sound, July, 1886) and Missouri (New Albany, fall, 1890) and north to British Columbia (Alberni, Vancouver Island, September 29, 1905.
Egg dates: California: Twenty-three records, April 28 to July 13; twelve records, June 7 to 25. Texas: Nine records, May 16 to September 10; four records, June 16 to July 12.