White-winged Wood Duck
Encyclopedia
The White-winged Duck or White-winged Wood Duck (Asarcornis scutulata) is a large species of duck
, formerly placed in the genus
Cairina
and allied with the dabbling ducks. However, mtDNA cytochrome b
and NADH dehydrogenase
subunit
2 sequence
analysis and the biogeographical
pattern of distribution indicate that the anatomical
similarity to the Muscovy Duck
is deceiving. Thus, this species might more appropriately be placed in a monotypic
genus, as Asarcornis scutulata, which appears to be unrelated to the Muscovy Duck but closer to the diving duck
s.
This secretive species is only known to feed at night. Its diet consists of seeds, aquatic plants, grain, rice, snails, small fish and insects. It inhabits stagnant or slow-flowing natural and artificial wetlands, within or adjacent to evergreen, deciduous or swamp forests, on which it depends for roosting and nesting, usually in tree-holes. Although lowlands (below c.200 m) provide optimum habitat, it occurs up to 1,400 m, especially on plateaux supporting sluggish perennial rivers and pools.
and Bangladesh
, through South East Asia to Java and Sumatra
. It is extinct in Java. In India, the duck is found only in the northeastern part of the country with main concentration in eastern Assam and adjacent areas of Arunachal Pradesh. However, in 2002 it had a population of only 800, with about 200 in Laos
, Thailand
, Vietnam
and Cambodia, 150 on Sumatra, notably in Way Kambas National Park
and 450 in India, Bangladesh and Burma.
In India, the key protected areas for the White-winged Duck are Dibru-Saikhowa National Park, Dihing-Patkai Wildlife Sanctuary, Nameri National Park and Namdapha National Park.
The White-winged Duck occurs in dense tropical evergreen forests, near rivers and swamps.
They tend to nest in tree cavities, and are threatened in part since the destruction of hollow trees is destroying their nesting localities. The draining of swamps and rivers and other forms of habitat destruction
is also destroying the habitat that they could survive in. Additional threats include loss of genetic variability, disturbance, hunting, and collection of eggs and chicks for food or pets.
Due to ongoing habitat loss, small population size, and because this duck is hunted for eggs, pets and food, the White-winged Duck is evaluated as Endangered on the IUCN Red List
of Threatened Species. It is listed on Appendix I of CITES.
Surprisingly the White-winged Duck is also found the central Sumatra province of Riau, specifically in the peatland acacia plantations of a large pulp and paper company. The plantations at least temporarily provide suitable habitat between periodic harvests (once every 4–5 years). The ducks are frequently observed along canals where large and overhanging Acacia trees provide shade and cover from predators and a haven in which to feed and rest. The quiet and still water in the canals of the plantations provides an undisturbed and secluded location, away from local communities which may hunt the ducks or collect eggs. Near-by natural forest conservation areas and greenbelts also provide suitable nesting and roosting habitat in close proximity to the canals.
It is the state bird of Assam
state in India.
Duck
Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...
, formerly placed in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Cairina
Cairina
Cairina is a genus of ducks in the bird family Anatidae.It has two species, which are similar anatomically but quite distinct in external morphology:* Muscovy Duck, Cairina moschata...
and allied with the dabbling ducks. However, mtDNA cytochrome b
Cytochrome b
Cytochrome b/b6 is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In addition, it commonly refers to a region of mtDNA used for population genetics and phylogenetics.- Function :...
and NADH dehydrogenase
NADH dehydrogenase
NADH dehydrogenase is an enzyme located in the inner mitochondrial membrane that catalyzes the transfer of electrons from NADH to coenzyme Q...
subunit
Protein subunit
In structural biology, a protein subunit or subunit protein is a single protein molecule that assembles with other protein molecules to form a protein complex: a multimeric or oligomeric protein. Many naturally occurring proteins and enzymes are multimeric...
2 sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
analysis and the biogeographical
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
pattern of distribution indicate that the anatomical
Anatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
similarity to the Muscovy Duck
Muscovy Duck
The Muscovy Duck is a large duck which is native to Mexico and Central and South America. A small wild population reaches into the United States in the lower Rio Grande Valley of Texas...
is deceiving. Thus, this species might more appropriately be placed in a monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus, as Asarcornis scutulata, which appears to be unrelated to the Muscovy Duck but closer to the diving duck
Diving duck
The diving ducks, commonly called pochards or scaups, are a category of duck which feed by diving beneath the surface of the water. They are part of the diverse and very large Anatidae family that includes ducks, geese, and swans....
s.
Description
This is one of the largest species of duck. Length is 66–81 cm (26–31.9 in) and wingspan is 116–153 cm (45.7–60.2 in). Males weigh 2.95–3.9 kg (6.5–8.6 lb), while females weigh 1.95–3.05 kg (4.3–6.7 lb). The most noticeable feature on adult birds is a dark body contrasting with the a whitish head and neck. Males have mostly dull yellowish bill, blackish mottling on head and upper neck, white lesser and median coverts and inner edges of tertials and bluish-grey secondaries. In flight, white wing-coverts contrast with the rest of the wings. Females are smaller and usually have more densely mottled head and upper neck. The juvenile is duller and browner.This secretive species is only known to feed at night. Its diet consists of seeds, aquatic plants, grain, rice, snails, small fish and insects. It inhabits stagnant or slow-flowing natural and artificial wetlands, within or adjacent to evergreen, deciduous or swamp forests, on which it depends for roosting and nesting, usually in tree-holes. Although lowlands (below c.200 m) provide optimum habitat, it occurs up to 1,400 m, especially on plateaux supporting sluggish perennial rivers and pools.
Distribution and Status
Historically, the White-winged Duck was widely distributed from north-east IndiaIndia
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
and Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
, through South East Asia to Java and Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
. It is extinct in Java. In India, the duck is found only in the northeastern part of the country with main concentration in eastern Assam and adjacent areas of Arunachal Pradesh. However, in 2002 it had a population of only 800, with about 200 in Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
and Cambodia, 150 on Sumatra, notably in Way Kambas National Park
Way Kambas National Park
Way Kambas National Park is a national park covering 1,300 square kilometres in Lampung province, southern Sumatra, Indonesia.It consists of swamp forest and lowland rain forest, mostly of secondary growth as result of extensive logging in the 1960s and 1970s...
and 450 in India, Bangladesh and Burma.
In India, the key protected areas for the White-winged Duck are Dibru-Saikhowa National Park, Dihing-Patkai Wildlife Sanctuary, Nameri National Park and Namdapha National Park.
The White-winged Duck occurs in dense tropical evergreen forests, near rivers and swamps.
They tend to nest in tree cavities, and are threatened in part since the destruction of hollow trees is destroying their nesting localities. The draining of swamps and rivers and other forms of habitat destruction
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
is also destroying the habitat that they could survive in. Additional threats include loss of genetic variability, disturbance, hunting, and collection of eggs and chicks for food or pets.
Due to ongoing habitat loss, small population size, and because this duck is hunted for eggs, pets and food, the White-winged Duck is evaluated as Endangered on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
of Threatened Species. It is listed on Appendix I of CITES.
Surprisingly the White-winged Duck is also found the central Sumatra province of Riau, specifically in the peatland acacia plantations of a large pulp and paper company. The plantations at least temporarily provide suitable habitat between periodic harvests (once every 4–5 years). The ducks are frequently observed along canals where large and overhanging Acacia trees provide shade and cover from predators and a haven in which to feed and rest. The quiet and still water in the canals of the plantations provides an undisturbed and secluded location, away from local communities which may hunt the ducks or collect eggs. Near-by natural forest conservation areas and greenbelts also provide suitable nesting and roosting habitat in close proximity to the canals.
It is the state bird of Assam
Assam
Assam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...
state in India.