occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDING: in Hawaiian Islands (Oahu); in North America in southern California, southwestern Arizona, central and eastern Texas, and Gulf Coast Louisiana south to central Mexico (to Nayarit, Jalisco, valley of Mexico, northern Veracruz); locally in southern Florida, the West Indies (Cuba, Hispaniola, Puerto Rico, and Grand Bahama south to Barbados, Grenada, Tobago, and Trinidad), El Salvador, central Honduras, and northwestern Costa Rica; in South America from Colombia, northern Venezuela, and Guianas south, west of Andes, to northwestern Peru, and east of Andes to southern Bolivia, Paraguay, and northeastern Argentina; in Old World in East Africa, Madagascar, India, Sri Lanka, and southwestern Burma (AOU 1998). NON-BREEDING: in Hawaiian Islands (Oahu), southern California and southern Arizona, Gulf Coast, and central to southern Florida south to Oaxaca, Tabasco, and Quintana Roo, and in the breeding range elsewhere in Neotropics, South America, and Old World (AOU 1998).
A medium-sized duck with long neck and legs.
Head, neck, chest and belly buffy to tawny-cinnamon.
Juvenile similar to adult.
Length: 51 cm
Weight: 710 grams
Catalog Number: USNM 135588
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Birds
Sex/Stage: Male; Adult
Preparation: Skin: Whole
Collector(s): E. Mearns
Year Collected: 1894
Locality: Unlucky Lake, ca 2 mi N of Mexican Boundary At Monument 221, San Diego, California, United States, North America
- Type: Wetmore & Peters. March 20, 1922. Proc. Biol. Soc. Washington. 35: 42.
Habitat and Ecology
Comments: Shallow fresh and brackish waters, preferring marshes, lagoons, wet cultivated fields, and occasionally forest (AOU 1983). Closely associated with rice culture in some areas (e.g., Florida). Generally on ground or in water; seldom perches in trees. Nests on hummocks among reeds and marshy vegetation (AOU 1983), in areas between ponds and swamps, or on levees and dikes and on rafts a few inches or more above water in flooded fields (Harrison 1979). Commonly lays eggs in the nests of other fulvous whistling ducks, sometimes in nests of ruddy duck and redhead.
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Some breeders from Florida migrate to Cuba (Turnbull et al. 1989).
Comments: Eats grain (especially rice), seeds, and structural plant material; forages in fields and on or near the bottom in shallow water .
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: > 300
Comments: Counts of 2820 birds from Lagunas de Topolobampo, Mexico; counts of 1000 birds not uncommon in South America; in Sahel, Africa, estimate about 100,000 birds; approximately 10,000 birds in January 1987 at Hail Haor, Bangladesh; up to 2300 counted on Lake Turkana, Kenya; record of 12,000 birds at Lake Chuali, Mozambique (Hoyo et al. 1992). Counts in United States unknown. Survey-wide relative abundance according to Breeding Bird Survey (BBS) for 1966-1996 is 1.68 birds per route (Sauer et al. 1997). In winter, Christmas Bird Count (CBC) shows 0.32 birds per 100 survey hours survey-wide for 1959-1988 (Sauer et al. 1996). In the U.S., the highest winter densities occur in eastern Florida and coastal Texas (Root 1988).
Life History and Behavior
No obvious courtship displays. Dabbles at and just below waterline. Makes shallow dives and tips-up. A filter-feeder, not a grazer.
Comments: Feeds mostly at night.
Lifespan, longevity, and ageing
Clutch size usually is 12-14. Incubation, by both sexes, lasts about 28 days. Young are tended by both parents, first fly at 55-63 days.
Molecular Biology and Genetics
Statistics of barcoding coverage: Dendrocygna bicolor
Public Records: 0
Specimens with Barcodes: 4
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N4B,N4N : N4B: Apparently Secure - Breeding, N4N: Apparently Secure - Nonbreeding
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Has an extensive range. Recent population trends in U.S. are increasing or stable.
Other Considerations: Benefits from rice fields.
Global Short Term Trend: Unknown
Comments: Expanding in the Caribbean (Raffaele 1989). More recently, declining in south and west (Ehrlich et al. 1988, NGS 1999). Populations may fluctuate widely. Trends outside of U.S. not known.
Global Long Term Trend: Unknown
Comments: Population has expanded into southeastern U.S. after the mid-1800s as rice cultures spread in Texas, Louisiana, and Florida. Became resident in south Florida in 1970s. Trends outside of U.S. not known.
Degree of Threat: C : Not very threatened throughout its range, communities often provide natural resources that when exploited alter the composition and structure over the short-term, or communities are self-protecting because they are unsuitable for other uses
Comments: PESTICIDES: Pesticide is a potential source of mortality. Formerly (1960s) negatively impacted by the use of the pesticide Aldrin in Louisiana ricefields. In 1984 and 1985, organochlorine and organophosphate were found in tissue samples from birds in Florida. Levels, however, were below those known to pose a threat to birds and there was no evidence of lethal impact (Turnbull et al. 1989).
Fulvous whistling duck
The fulvous whistling duck or fulvous tree duck (Dendrocygna bicolor) is a whistling duck that breeds across the world's tropical regions in much of Central and South America, the West Indies, the southern US, sub-Saharan Africa and the Indian subcontinent. It has mainly reddish brown plumage, long legs and a long grey bill, and shows a distinctive white band across its black tail in flight. Like other members of its ancient lineage, it has a whistling call which is given in flight or on the ground. The preferred habitat is shallow lakes, paddy fields or other wetlands with plentiful vegetation.
The nest, built from plant material and unlined, is placed among dense vegetation or in a tree hole. The typical clutch is around ten whitish eggs. The breeding adults, which pair for life, take turns to incubate, and the eggs hatch in 24–29 days. The downy grey ducklings leave the nest within a day or so of hatching, but the parents continue to protect them until they fledge around nine weeks later.
The fulvous whistling duck feeds in wetlands by day or night on seeds and other parts of plants. It is sometimes regarded as a pest of rice cultivation, and is also shot for food in parts of its range. Despite hunting, poisoning by pesticides and natural predation by mammals, birds and reptiles, the large numbers and huge range of this duck mean that it is classified as Least Concern by the International Union for Conservation of Nature (IUCN).
The whistling ducks, Dendrocygna, are a distinctive group of eight bird species within the duck, goose and swan family Anatidae, which are characterised by a hump-backed, long-necked appearance and the whistled flight calls that give them their English name. They were an early split from the main duck lineage, and were predominant in the Late Miocene before the subsequent extensive radiation of more modern forms in the Pliocene and later. The fulvous whistling duck forms a superspecies with the wandering whistling duck. It has no recognised subspecies, although the birds in northern Mexico and the southern US have in the past been assigned to D. b. helva, described as having paler and brighter underparts and a lighter crown than D. b. bicolor.
The duck was first described by Johann Friedrich Gmelin in 1789 and given the name Anas fulva but the name was "preoccupied," or already used, by Friedrich Christian Meuschen in 1787 for another species.[a] This led to the next available name proposed by French ornithologist Louis Jean Pierre Vieillot in 1816 from a Paraguayan specimen as Anas bicolor[b] The whistling ducks were moved to their current genus, Dendrocygna, by British ornithologist William John Swainson in recognition of their differences from other ducks. The genus name is derived from the Ancient Greek dendron, "tree", and Latin cygnus, "swan", and bicolor is Latin for "two-coloured". "Fulvous" means reddish-yellow, and is derived from the Latin equivalent fulvus. Old and regional names include large whistling teal, brown tree duck, Mexican duck, squealer and Spanish cavalier.
The fulvous whistling duck is 45–53 cm (18–21 in) long; the male weighs 748–1,050 g (26.4–37.0 oz), and the female averages marginally lighter at 712–1,000 g (25.1–35.3 oz). It is a long-legged duck, mainly golden-brown with a darker back and an obvious blackish line down the back of its neck. It has whitish stripes on its flanks, a long grey bill and grey legs. In flight, the wings are brown above and black below, with no white markings, and a white crescent on the rump contrasts with the black tail. All plumages are fairly similar, but the female is slightly smaller and duller-plumaged than the male. The juvenile has paler underparts, and appears generally duller, especially on the flanks. There is a complete wing moult after breeding, and birds then seek the cover of dense wetland vegetation while they are flightless. Body feathers may be moulted throughout the year, although each feather is replaced only once annually.
These are noisy birds with a clear whistling kee-wee-ooo call given on the ground or in flight. Quarrelling birds also have a harsh repeated kee. In flight, the beating wings produce a dull sound. The calls of males and females show differences in structure and an acoustic analysis on 59 captive birds demonstrated 100% accuracy in sexing when compared with molecular methods.
Adult birds in Asia can be confused with the similar lesser whistling duck, although that species is smaller, has a blackish crown and lacks an obvious dark stripe down the back of the neck. Juvenile fulvous whistling ducks are very like young lesser whistling ducks, but the crown colour is still a distinction. Juvenile comb ducks are bulkier than whistling ducks and have a dark cap to the head. In South America and Africa, juvenile white-faced whistling ducks are separable from fulvous by their dark crowns, barred flanks and chestnut breasts.
Distribution and habitat
The fulvous whistling duck has a very large range extending across four continents. It breeds in lowland South America from northern Argentina to Colombia and then up to the southern US and the West Indies. It is found in a broad belt across sub-Saharan Africa and down the east of the continent to South Africa and Madagascar. The Indian subcontinent is the Asian stronghold.
It undertakes seasonal movements in response to the availability of water and food. African birds move southwards in the southern summer to breed and return north in the winter, and Asian populations are highly nomadic due to the variability of rainfall. This species has strong colonising tendencies, having expanded its range in Mexico, the US and the West Indies in recent decades. Wandering birds can turn up far beyond the normal range, sometimes staying to nest, as in Morocco, Peru and Hawaii.
The fulvous whistling duck is found in lowland marshes and swamps in open, flat country, and it avoids wooded areas. It is particularly attracted to wetlands with plenty of emergent vegetation, including rice fields. It is not normally a mountain species, breeding in Venezuela, for example, only up 300 m (980 ft), but the single Peruvian breeding record was at 4,080 m (13,390 ft).
This species is usually found in small groups, although substantial flocks can form at favoured sites. It walks well, without waddling, and although it normally feeds by upending, it can dive if necessary. It does not often perch in trees, unlike other whistling ducks. It flies at low altitude with slow wingbeats and trailing feet, in loose flocks rather than tight formation. It feeds during the day and at night in fairly large flocks, often with other whistling duck species, but rests or sleeps in smaller groups in the middle of the day. They are noisy and display their aggression towards other individuals by throwing back their heads. Before taking off in alarm, they often shake their head sideways.
A number of arthropod parasites have been recorded on this duck, including chewing mites of the families Philopteridae and Menoponidae, feather mites and skin mites. Internal helminth parasites include roundworms, tapeworms and flukes. In a survey in Florida, all 30 ducks tested carried at least two helminth species, although none had blood parasites. Only one duck had no mites or lice.
Breeding coincides with the availability of water. In South America and South Africa, the main nesting period is December–February, in Nigeria it is July–December, and in North America mid-May–August. In India, the breeding season is from June to October but peaking in July and August. Fulvous whistling ducks show lifelong monogamy, although the courtship display is limited to some mutual head-dipping before mating and a short dance after copulation in which the birds raise their bodies side-by-side while treading water.
Pairs may breed alone or in loose groups. In South Africa, nests may be within 50 m (160 ft) of each other, and breeding densities of up to 13.7 nests per square kilometre (35.5 per square mile) have been found in Louisiana. The nest, 19–26 cm (7.5–10.2 in) across, is made from plant leaves and stems and has little or no soft lining. It is usually built in dense vegetation and close to water, but sometimes in tree holes. In India, the use of tree holes, and even the old nests of raptors or crows, is much more common than elsewhere. Eggs are laid at roughly 24–36 hour intervals, starting before the nest is complete, resulting in some losses from the clutch. They are whitish and on average measure 53.4 x 40.7 mm (2.1 x 1.6 in) and weigh 50.4 g (1.78 oz). The clutch is usually around ten eggs, but other females sometimes lay into the nest, so 20 or more may be found on occasion. Eggs may also be added to the nests of other species, like ruddy duck.
Both sexes incubate, changing over once a day, with the male often taking the greater share of this duty. The eggs hatch in about 24–29 days, The downy ducklings are grey, with paler upperparts, and a white band on the neck, and weigh 22–38 g (0.78–1.34 oz) within a day of hatching. Like all ducklings, they are precocial and leave the nest after a day or so, but the parents protect them until they fledge around nine weeks later. Eggs and duckling may be preyed on by mammals, birds and reptiles, although one parent may try to distract a potential predator with a broken-wing display while the other adult leads the ducklings away. Birds are sexually mature after one year, and the maximum known age is 6.5 years.
In South Africa, a few records of hybridization with the white-faced whistling duck have been noted in the wild, although in most parts of southern Africa, the two species breed at different times, bicolor during the dry season (April to September) and viduata during the rains (October to March). Hybridization in captivity is more frequent but limited to other species in the genus Dendrocygna.
The fulvous whistling duck feeds in wetlands by day or night, often in mixed flocks with relatives such as white-faced or black-bellied whistling ducks. Its food is generally plant material, including seeds, bulbs, grasses and stems, but females may include animal items such as aquatic worms, molluscs and insects as they prepare for egg-laying, which may then comprise up to 4% of their diet. Ducklings may also eat a few insects. Foraging is by picking plant items while walking or swimming, by upending, or occasionally by diving to a depth of up to 1 m (3 ft). Favoured plants include water snowflake, aquatic ragweeds, bourgou millet, shama grass, Cape blue water lily, waxy-leaf nightshade, beakrush, flatsedge and polygonums. Rice is normally a small part of the diet, and a survey in Cuban rice fields found that the plants taken were mainly weeds growing with the crop. However, in a study in Louisiana, 25% of the diet of incubating females consisted of the cereal.
The International Union for Conservation of Nature (IUCN) estimates the population of the fulvous whistling duck to be from 1.3–1.5 million individuals. This may be an underestimate since regional assessments suggest 1 million birds in the Americas, 1.1 million in Africa and at least 20,000 in South Asia. Although the population appear to be declining, the decrease is not rapid enough to trigger the vulnerability criteria. The large numbers and huge breeding range mean that this duck is classified by the IUCN as being of Least Concern. It is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.
The fulvous whistling duck has expanded its range in the West Indies, and into the southern US. A series of invasions from South America and reaching the eastern US commenced around 1948, fueled by rice cultivation, and breeding was recorded in Cuba in 1964, and Florida in 1965. Some Florida birds still winter in Cuba. In Africa, it bred on the Cape Peninsula between 1940 and the 1960s. A survey of eighteen species which had colonised the area in recent decades found that most were wetland species that had used irrigated farmland as "stepping stones" across the arid country separating the peninsula from the breeding main range. However, the status of the two whistling duck species featured in the research is dubious since they are popular ornamental species, so their origin is unclear.
Outside North America it is subject to hunting for food or because of its liking for rice, and persecution means that it is now rare in Madagascar. Pesticides used on rice fields may also have an adverse impact, causing liver and breast muscle damage even at sub-lethal levels.
- Scientific names are given in accordance with strict chronological priority, so Gmelin's name could not be used since it had previously allocated to another species. The identity of the duck designated as Anas fulva by Meuschen is not known.
- Le Canard roux et noir
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One of the most widespread species of waterfowl in the world, the Fulvous Whistling-Duck has a limited distribution in the southern United States. Its mostly seed-based diet makes it fond of rice-growing areas.
In some ways, whistling-ducks act more like swans than ducks. The male helps to take care of the offspring and a mated pair stays bonded for many years.
Pesticides applied to rice in the 1960s caused declines in Texas and Louisiana populations. Numbers have recovered and stabilized since then.
The Fulvous Whistling-Duck is a frequent nest parasite, laying eggs in other Fulvous Whistling-Duck nests, as well as the nests of other duck species. These other duck species often lay their eggs in Fulvous Whistling-Duck nests as well.
Unlike many other ducks which have elaborate courtship displays, whistling-ducks appear to have none.
Other than in agricultural habitats, the Fulvous Whistling-Duck nests only rarely in the United States. It started breeding in the United States only in the late 19th and early 20th centuries, nesting in rice fields.
Names and Taxonomy
Comments: May constitute a superspecies with D. arcuata (AOU 1998).