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-Saharan Africa and the Indian subcontinent. It has plumage 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 consists of wetlands with plentiful vegetation, including shallow lakes and paddy fields. 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.
Taxonomy
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.[2] They were an early split from the main duck lineage,[3] and were predominant in the Late Miocene before the subsequent extensive radiation of more modern forms in the Pliocene and later.[4] 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,[5] described as having paler and brighter underparts and a lighter crown than D. b. bicolor.[6]
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.[7][lower-alpha 1] This led to the next available name proposed by French ornithologistLouis Pierre Vieillot in 1816 from a Paraguayan specimen as Anas bicolor.[9][lower-alpha 2] The whistling ducks were moved to their current genus, Dendrocygna, by British ornithologistWilliam John Swainson in recognition of their differences from other ducks.[10] The genus name is derived from the Ancient Greek dendron, "tree", and Latin cygnus, "swan",[11] and bicolor is Latin for "two-coloured".[12] "Fulvous" means reddish-yellow, and is derived from the Latin equivalent fulvus.[13] Old and regional names include large whistling teal,[5] brown tree duck, Mexican duck, pichiguila, squealer and Spanish cavalier.[14]
Description
The fulvous whistling duck is 45–53cm (18–21in) long; the male weighs 748–1,050g (26.4–37.0oz), and the female averages marginally lighter at 712–1,000g (25.1–35.3oz).[5] The wingspan ranges from 85 to 93cm.[15]
It is a long-legged duck, mainly different shades of brown; head, neck and breast are particularly rich buff (fulvous) with a darker back.[16] 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.[17][18] 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.[5] 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; each feather is replaced only once annually.[19]
These are noisy birds with a clear whistling kee-wee-ooo call given on the ground or in flight, frequently heard at night.[16] Quarrelling birds also have a harsh repeated kee. In flight, the beating wings produce a dull sound.[20] 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.[21]
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.[20]
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.[20] 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.[20] 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.[20][16] 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.[16] 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.[16] Wandering birds can turn up far beyond the normal range, sometimes staying to nest, as in Morocco, Peru and Hawaii.[5]
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 300m (980ft),[18] but the single Peruvian breeding record was at 4,080m (13,390ft).[5]
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.[20] 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.[19] 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.[22]
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.[5] In India, the breeding season is from June to October but peaking in July and August.[26] Fulvous whistling ducks show lifelong monogamy; 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.[19]
Pairs may breed alone or in loose groups. In South Africa, nests may be within 50m (160ft) of each other, and breeding densities of up to 13.7nests per square kilometre (35.5per square mile) have been found in Louisiana. The nest, 19–26cm (7.5–10.2in) 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), in marsh vegetation, and in artificial habitats such as shallowly-flooded rice fields, in dense vegetation and close to water,[5][16][18] 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.[20] Eggs are laid at roughly 24- to 36-hour intervals, starting before the nest is complete, resulting in some losses from the clutch. They are whitish and on average measure 53.4mm ×40.7mm (2.10in ×1.60in) and weigh 50.4g (1.78oz).[19] The clutch is usually around ten eggs, but other females sometimes lay into the nest, so 20 or more may be found on occasion.[5] Eggs may also be added to the nests of other species, like ruddy duck.[27]
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,[5] The downy ducklings are grey, with paler upperparts,[19] and a white band on the neck,[14] and weigh 22–38g (0.78–1.34oz) 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.[5] 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.[19] Birds are sexually mature after one year, and the maximum known age is 6.5years.[5]
In South Africa, a few records of hybridization with the white-faced whistling duck have been noted in the wild;[28][29] 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).[30] Hybridization in captivity is more frequent but limited to other species in the genus Dendrocygna.[31][32]
Feeding
Long legs enable the duck to stand erect and walk without waddling.
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 1m (3.3ft). 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 cereal.[5]
Status
The International Union for Conservation of Nature (IUCN) estimates the population of the fulvous whistling duck to be from 1.3 to 1.5million individuals around the world.[1] This may be an underestimate since regional assessments suggest 1million birds in the Americas, 1.1million in Africa and at least 20,000 in South Asia for a grand total of 2.12 million ducks around the world.[19] 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.[1] It is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.[33]
The fulvous whistling duck has expanded its range in the West Indies, and into the southern US.[20] 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,[19] and Florida in 1965. Some Florida birds still winter in Cuba.[34] 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.[35]
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,[5] causing liver and breast muscle damage even at sub-lethal levels.[36]
Notes
↑ 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.[8]
The pintail or northern pintail is a duck species with wide geographic distribution that breeds in the northern areas of Europe and across the Palearctic and North America. It is migratory and winters south of its breeding range to the equator. Unusually for a bird with such a large range, it has no geographical subspecies if the possibly conspecific duck Eaton's pintail is considered to be a separate species.
The gadwall is a common and widespread dabbling duck in the family Anatidae.
The mallard or wild duck is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa. It has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, Colombia, the Falkland Islands, and South Africa. This duck belongs to the subfamily Anatinae of the waterfowl family Anatidae. Males have green heads, while the females have mainly brown-speckled plumage. Both sexes have an area of white-bordered black or iridescent purple or blue feathers called a speculum on their wings; males especially tend to have blue speculum feathers. The mallard is 50–65 cm (20–26 in) long, of which the body makes up around two-thirds the length. The wingspan is 81–98 cm (32–39 in) and the bill is 4.4 to 6.1 cm long. It is often slightly heavier than most other dabbling ducks, weighing 0.7–1.6 kg (1.5–3.5 lb). Mallards live in wetlands, eat water plants and small animals, and are social animals preferring to congregate in groups or flocks of varying sizes.
The redhead is a medium-sized diving duck. The scientific name is derived from Greek aithuia, an unidentified seabird mentioned by authors including Hesychius and Aristotle, and Latin americana, of America. The redhead is 37 cm (15 in) long with an 84 cm (33 in) wingspan. Redhead weight ranges from 2.0 to 2.5 lbs, with males weighing an average of 2.4 lbs and females weighing an average of 2.1 lbs. It belongs to the genus Aythya, together with 11 other described species. The redhead and the common pochard form a sister group which together is sister to the canvasback.
The blue-winged teal is a species of bird in the duck, goose, and swan family Anatidae. One of the smaller members of the dabbling duck group, it occurs in North America, where it breeds from southern Alaska to Nova Scotia, and south to northern Texas. It winters along the Pacific and Atlantic coasts and south into the Caribbean islands and Central America.
The common pochard, known simply as pochard in the United Kingdom, is a medium-sized diving duck in the family Anatidae. It is widespread across the Palearctic. It breeds primarily in the steppe regions of Scandinavia and Siberia, and winters further south and west.
The tufted duck or tufted pochard is a small diving duck with a population of close to one million birds, found in northern Eurasia. The scientific name is derived from Ancient Greek aithuia, an unidentified seabird mentioned by authors including Hesychius and Aristotle, and Latin fuligo 'soot' and gula 'throat'.
The wood duck or Carolina duck is a species of perching duck found in North America. The drake wood duck is one of the most colorful North American waterfowls.
The mandarin duck is a perching duck species native to the East Palearctic. It is sexually dimorphic, males showing a dramatic difference from the females. It is medium-sized, at 41–49 cm (16–19 in) long with a 65–75 cm (26–30 in) wingspan. It is closely related to the North American wood duck, the only other member of the genus Aix. 'Aix' is an Ancient Greek word which was used by Aristotle to refer to an unknown diving bird, and 'galericulata' is the Latin for a wig, derived from galerum, a cap or bonnet. Outside of its native range, the mandarin duck has a large introduced population in the British Isles and Western Europe, with additional smaller introductions in North America.
The white-backed duck is a waterbird of the family Anatidae. It is distinct from all other ducks, but most closely related to the whistling ducks in the subfamily Dendrocygninae, though also showing some similarities to the stiff-tailed ducks in the subfamily Oxyurinae. It is the only member of the genus Thalassornis.
The lesser whistling duck, also known as Indian whistling duck or lesser whistling teal, is a species of whistling duck that breeds in the Indian subcontinent and Southeast Asia. They are nocturnal feeders that during the day may be found in flocks around lakes and wet paddy fields. They can perch on trees and sometimes build their nest in the hollow of a tree. This brown and long-necked duck has broad wings that are visible in flight and produces a loud two-note wheezy call. It has a chestnut rump, differentiating it from its larger relative, the fulvous whistling duck, which has a creamy white rump.
The white-faced whistling duck is a whistling duck that breeds in sub-Saharan Africa and much of South America.
The comb duck or American comb duck, is an unusual duck, found in tropical wetlands in continental South America south to the Paraguay River region in eastern Paraguay, southeastern Brazil and extreme northeastern Argentina, and as a vagrant on Trinidad.
The West Indian whistling duck is a whistling duck that breeds in the Caribbean. Alternative names are black-billed whistling duck and Cuban whistling duck.
The Australian wood duck, maned duck or maned goose is a dabbling duck found throughout much of Australia. It is the only living species in the genus Chenonetta. Traditionally placed in the subfamily Anatinae, it might belong to the subfamily Tadorninae (shelducks); the ringed teal may be its closest living relative.
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, Dendrocygna, which contains eight living species, and one undescribed extinct species from Aitutaki of the Cook Islands, but other taxonomists also list the white-backed duck under the subfamily.
The black-bellied whistling duck, formerly called the black-bellied tree duck, is a whistling duck that before 2000 bred mainly in the southernmost United States, Mexico, and tropical Central to south-central South America. It can be found year-round in much of the United States. It has been recorded in every eastern state and adjacent Canadian province. Since it is one of only two whistling duck species native to North America, it is occasionally just known as the "whistling duck" or "Mexican squealer" in the southern USA.
The spotted whistling duck is a member of the duck family Anatidae. It is also referred to as the "spotted tree duck". This duck can be found in Indonesia, New Guinea, Australia and the Philippines. Spotted ducks are also held in captive populations.
The wandering whistling duck is a species of whistling duck. They inhabit tropical and subtropical Australia, the Philippines, Borneo, Indonesia, Papua New Guinea and the Pacific Islands.
The blue-billed teal, spotted teal or Hottentot teal is a species of dabbling duck of the genus Spatula. It is migratory resident in eastern and southern Africa, from Sudan and Ethiopia west to Niger and Nigeria and south to South Africa and Namibia. In west Africa and Madagascar it is sedentary.
1 2 3 4 5 6 Hohman, W. L.; Lee, S. A. (2020). "Birds of the World". Birds of the World (S. M. Billerman, Editor)– via Cornell Lab of Ornithology, Ithaca, NY, USA.
↑ McDaniel, Burruss; Tuff, Donald; Bolen, Eric (1966). "External parasites of the Black-bellied Tree Duck and other dendrocygnids". The Wilson Bulletin. 78 (4): 462–468. JSTOR4159536.
↑ Arnold, Don C (2006). "Review of the genus Acidoproctus (Phthiraptera: Ischnocera: Philopteridae), with description of a new species". Journal of the Kansas Entomological Society. 79 (3): 272–282. doi:10.2317/0509.26.1. JSTOR25086333. S2CID86245106.
↑ Turnbull, Richard E; Johnson, Fred A; Brakhage, David H (1989). "Status, distribution, and foods of Fulvous Whistling-Ducks in South Florida". The Journal of Wildlife Management. 53 (4): 1046–1051. doi:10.2307/3809607. JSTOR3809607.
↑ Turnbull, Richard E; Johnson, Fred A; Hernandez, Maria de los A; Wheeler, Willis B; Toth, John P (1989). "Pesticide residues in Fulvous Whistling-Ducks from South Florida". The Journal of Wildlife Management. 53 (4): 1052–1057. doi:10.2307/3809608. JSTOR3809608.
Cited texts
Ali, Salim; Ripley, Dillon S (1978). Handbook of the birds of India and Pakistan. Volume 1 (2nded.). New Delhi: Oxford University Press.
Barlow, Clive; Wacher, Tim; Disley, Tony (1997). A Field Guide to birds of The Gambia and Senegal. Boroughbridge, Sussex: Pica Press. ISBN978-1-873403-32-7.
Feduccia, Alan (1999). The Origin and Evolution of Birds. New Haven, Connecticut: Yale University Press. ISBN978-0-300-07861-9.
Hilty, Steven L (2003). Birds of Venezuela. London: Christopher Helm. ISBN978-0-7136-6418-8.
Kear, Janet (2005). Ducks, Geese and Swans. Vol.1. Oxford: Oxford University Press. ISBN978-0-19-854645-0.
Madge, Steve; Burn, Hilary (1988). Wildfowl: An Identification Guide to the Ducks, Geese and Swans of the World (Helm Identification Guides). London: Christopher Helm. ISBN978-0-7470-2201-5.
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