The fulvous whistling duck or fulvous tree duck (''Dendrocygna bicolor'') is a species of

whistling duck The whistling ducks or tree ducks are a subfamily, Dendrocygninae, of the duck, goose and swan family of birds, Anatidae. In other taxonomic schemes, they are considered a separate family, Dendrocygnidae. Some taxonomists list only one genus ...

that breeds across the world's tropical regions in much of

Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

, the

West Indies The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greate ...

, the southern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

sub-Saharan Africa Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa that lies south of the Sahara. These include West Africa, East Africa, Central Africa, and Southern Africa. Geopolitically, in addition to the List of sov ...

and the

Indian subcontinent The Indian subcontinent is a physiographical region in Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian Ocean from the Himalayas. Geopolitically, it includes the countries of Bangladesh, Bhutan, In ...

. It has

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

that is mainly reddish brown, 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. Its preferred

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

consists of

wetlands A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

with plentiful vegetation, including shallow lakes and

paddy fields A paddy field is a flooded field of arable land used for growing semiaquatic crops, most notably rice and taro. It originates from the Neolithic rice-farming cultures of the Yangtze River basin in southern China, associated with pr ...

. The nest, built from plant material and unlined, is placed among dense vegetation or in a tree hole. The typical

clutch A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...

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 Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnera ...

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

pesticide Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and ...

s 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 A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. ...

by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

Taxonomy

The

s, ''Dendrocygna'', are a distinctive group of eight bird species within the duck, goose and swan family,

Anatidae The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, flo ...

, which are characterised by a hump-backed, long-necked appearance and the whistled flight calls that give them their English name.Madge & Burn (1988) p. 124. They were an early split from the main duck lineage,Feduccia (1999) p. 219. and were predominant in the

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The ...

before the subsequent extensive radiation of more modern forms in the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58superspecies with the

wandering whistling duck The wandering whistling duck (''Dendrocygna arcuata'') is a species of whistling duck. They inhabit tropical and subtropical Australia, the Philippines, Borneo, Indonesia, Papua New Guinea and the Pacific Islands. Taxonomy There are three subspe ...

. It has no recognised

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

, 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 , fields = , workplaces = University of GöttingenUniversity of Tübingen , alma_mater = University of Tübingen , doctoral_advisor = Philipp Friedrich Gmelin Ferdinand Christoph Oetinger , academic_advisors = , docto ...

in 1789 and given the name ''Anas fulva'' but the name was "preoccupied", or already used, by

Friedrich Christian Meuschen Friedrich Christian Meuschen (15 September 1719 – 20 February 1811) was a German diplomat and conchologist born in Hanau. He was the son of theologian Johann Gerhard Meuschen (1680–1743). Meuschen was a diplomatic representative in The Hague, ...

in 1787 for another species. This led to the next available name proposed by French

ornithologist Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and th ...

Louis Jean Pierre Vieillot Louis Pierre Vieillot (10 May 1748, Yvetot – 24 August 1830, Sotteville-lès-Rouen) was a French ornithologist. Vieillot is the author of the first scientific descriptions and Linnaean names of a number of birds, including species he collec ...

in 1816 from a Paraguayan specimen as ''Anas bicolor''.Vieillot (1816
pp. 136–137
The whistling ducks were moved to their current genus, ''Dendrocygna'', by British

William John Swainson William John Swainson FLS, FRS (8 October 1789 – 6 December 1855), was an English ornithologist, malacologist, conchologist, entomologist and artist. Life Swainson was born in Dover Place, St Mary Newington, London, the eldest son of Jo ...

in recognition of their differences from other ducks.Swainson (1837
p. 365
The genus name is derived from the Ancient Greek ''dendron'', "tree", and Latin ''cygnus'', "swan",Jobling (2010) pp. 128, 133. and '' bicolor'' is Latin for "two-coloured".Jobling (2010) p. 72. " 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, pichiguila, squealer and Spanish cavalier.

Description

The fulvous whistling duck is long; the male weighs , and the female averages marginally lighter at . The wingspan ranges from 85 to 93 cm. It is a long-legged duck, mainly different shades of brown; head, neck and breast are particularly rich

buff Buff or BUFF may refer to: People * Buff (surname), a list of people * Buff (nickname), a list of people * Johnny Buff, ring name of American world champion boxer John Lisky (1888–1955) * Buff Bagwell, a ring name of American professional w ...

(fulvous) with a darker back. The mantle is more darker shade of brown with buff-tipped feathers, the flight feathers and tail are dark brown, and a dark brown to black stripe runs through the center of the crown down the back of the neck to the base of the mantle. 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.Barlow ''et al.'' (1997) p. 135.Hilty (2003) p. 195. 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 In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...

after breeding, and birds then seek the cover of dense wetland vegetation while they are flightless. Body feathers may be moulted throughout the year; each feather is replaced only once annually.Kear (2005) pp. 199–202. These are noisy

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s with a clear whistling ''kee-wee-ooo'' call given on the ground or in flight, frequently heard at night. 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, which 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. Fulvous Whistling Duck from The Crossley ID Guide Eastern Birds crop

Fulvous Whistling Duck from The Crossley ID Guide Eastern Birds crop

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

. It is found in a broad belt across

and down the east of the continent to

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

and

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Afric ...

. The

is the Asian stronghold. It undertakes seasonal

movements Movement may refer to: Common uses * Movement (clockwork), the internal mechanism of a timepiece * Motion, commonly referred to as movement Arts, entertainment, and media Literature * "Movement" (short story), a short story by Nancy Fu ...

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 with northerly range expansions into California in late 19th century and rice-growing regions of the U.S. Gulf Coastal Plain in the early to mid-20th century, given its affinity for rice-growing areas. Breeding in the northern American region is restricted to the Gulf Coastal Plain of Texas and Louisiana and localities in southern California and south- and east-central Florida. Observations of the bird outside the nesting season, especially since the 1950s have been recorded in temperate regions as far north as the Mississippi River Basin, eastern Great Lakes region, and along the Pacific and Atlantic Coasts right up to southern Canada. 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, rice fields, flat country, and it avoids wooded areas. It is not normally a mountain species, breeding in Venezuela, for example, only up , but the single Peruvian breeding record was at .

Behaviour

Dendrocygna bicolor, London Wetland Centre, UK - Diliff

This species is usually found in small groups, but substantial flocks can form at favoured sites. It walks well, without waddling, and normally feeds by upending, though 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.Johnsgard (1965) pp. 16–20 Several

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

parasites have been recorded on this duck, including chewing mites of the families Philopteridae and Menoponidae, feather mites and skin

mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear e ...

s. Internal

helminth Parasitic worms, also known as helminths, are large macroparasites; adults can generally be seen with the naked eye. Many are intestinal worms that are soil-transmitted and infect the gastrointestinal tract. Other parasitic worms such as ...

parasites include roundworms,

tapeworms Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of ...

and flukes. In a survey in Florida, all 30 ducks tested carried at least two helminth species; none had blood parasites. Only one duck had no mites or lice.

Breeding

Breeding coincides with the availability of water. In South America and South Africa, the main nesting period is December–February, in

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

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 Monogamy ( ) is a form of dyadic relationship in which an individual has only one partner during their lifetime. Alternately, only one partner at any one time ( serial monogamy) — as compared to the various forms of non-monogamy (e.g., pol ...

; 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 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 Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bord ...

. The nest, across, is made from plant leaves and stems and has little or no soft lining. It is usually built on the ground (unlike the

Black-bellied whistling duck The black-bellied whistling duck (''Dendrocygna autumnalis''), formerly called the black-bellied tree duck, is a whistling duck that breeds from the southernmost United States, Mexico, and tropical Central to south-central South America. In the ...

), in marsh vegetation, and in artificial habitats such as shallowly-flooded rice fields, 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

crow A crow is a bird of the genus '' Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifica ...

s, is much more common than elsewhere. Eggs are laid at roughly 24- to 36-hour intervals, starting before the nest is complete, resulting in some losses from the

. They are whitish and on average measure and weigh . 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,Phillips (1922
pp. 128–129.
/ref> and weigh 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

around nine weeks later. Eggs and duckling may be preyed on by mammals, birds and reptiles; 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; in most parts of southern

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

, 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''.Kear (2005) p. 188.

Feeding

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 duck The black-bellied whistling duck (''Dendrocygna autumnalis''), formerly called the black-bellied tree duck, is a whistling duck that breeds from the southernmost United States, Mexico, and tropical Central to south-central South America. In the ...

s. 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 . Favoured plants include water snowflake, aquatic ragweeds, bourgou millet, shama grass, Cape blue water lily, waxy-leaf nightshade, beakrush, flatsedge and

polygonum ''Polygonum'' is a genus of about 130 species of flowering plant in the buckwheat and knotweed family Polygonaceae. Common names include knotweed and knotgrass (though the common names may refer more broadly to plants from Polygonaceae). In ...

s. 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 cereal.

Status

The

(IUCN) estimates the population of the fulvous whistling duck to be from 1.3 to 1.5 million individuals around the world. 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 for a grand total of 2.12 million ducks around the world. The population appears to be declining, but the decrease is not rapid enough to trigger the vulnerability criteria for extinction. The large numbers and huge breeding range mean that this duck is classified by the IUCN as being of

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. ...

. 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.Madge & Burn (1988) pp. 126–127. 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 The Cape Peninsula ( af, Kaapse Skiereiland) is a generally mountainous peninsula that juts out into the Atlantic Ocean at the south-western extremity of the African continent. At the southern end of the peninsula are Cape Point and the Ca ...

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.

Notes

References

Cited texts

* * * * * * * * * * *

External links

Fulvous Whistling-duck videos
at the Internet Bird Collection
Tribe Dendrocygnini (Whistling or Tree Ducks)
from Johnsgard, Paul A. ''Ducks, Geese, and Swans of the World''
Species text
in ''The Atlas of Southern African Birds''
Calls
at Xeno-canto {{Authority control

fulvous whistling duck The fulvous whistling duck or fulvous tree duck (''Dendrocygna bicolor'') is a species of whistling duck that breeds across the world's tropical regions in much of Mexico and South America, the West Indies, the southern United States, sub- ...

Birds of the Americas Birds of the Caribbean Birds of the Dominican Republic Birds of Haiti Birds of Sub-Saharan Africa Birds of South Asia Native birds of the Southeastern United States Mangrove fauna