Comb duck

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Comb duck
Amerikanische Hockerglanzgans Sarkidiornis sylvicola 05 (1).jpg
male
Amerikanische Hockerglanzgans Sarkidiornis sylvicola 050807.jpg
female
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Sarkidiornis
Species:
S. sylvicola
Binomial name
Sarkidiornis sylvicola
Sarkidiornis sylvicola map.svg
Synonyms

Sarkidiornis melanotos sylvicola

The comb duck or American comb duck (Sarkidiornis sylvicola), 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, [2] and as a vagrant on Trinidad.

Contents

Most taxonomic authorities split this species and the knob-billed duck from each other. The comb duck is generally smaller in size when compared to the knob-billed duck, and flanks are darker (black in males, medium grey in females).

Systematics

Uncertainty surrounds the correct systematic placement of this species. Initially, it was placed in the dabbling duck subfamily Anatinae. Later, it was assigned to the "perching ducks", a paraphyletic assemblage of waterfowl most of which are intermediate between dabbling ducks and shelducks. As the "perching ducks" were split up, the comb duck was moved to the Tadorninae or shelduck subfamily. [3]

Analysis of mtDNA sequences of the cytochrome b and NADH dehydrogenase subunit 2 genes, however, suggests that it is a quite basal member of the Anatidae, vindicating the earliest placement, but its closest living relatives cannot be resolved to satisfaction without further study. [4]

Description

This common species is unmistakable. It is one of the largest species of duck. Length can range from 56 to 76 cm (22 to 30 in), wingspan ranges from 116 to 145 cm (46 to 57 in) and weight from 1.03 to 2.9 kg (2.3 to 6.4 lb). [5] [6] [7] Adults have a white head freckled with dark spots, and a pure white neck and underparts. The upperparts are glossy blue-black upperparts, with bluish and greenish iridescence especially prominent on the secondaries (lower arm feathers). The male is much larger than the female, and has a large black knob on the bill.

If seen at a distance, immature comb ducks can also be mistaken for a fulvous whistling duck (Dendrocygna bicolor). However, knob-billed ducks in immature plumage are rarely seen without adults nearby and thus they are usually easily identified, too. [3]

Ecology

It breeds in still freshwater swamps and lakes in the tropics. It is largely resident, apart from dispersion in the wet season. [3]

This duck feeds on vegetation by grazing or dabbling [3] and to a lesser extent on small fish, invertebrates, and seeds. It can become a problem to rice farmers. Knob-billed ducks often perch in trees. They are typically seen in flocks, small in the wet season, up to 100 in the dry season. Sometimes they separate according to sex. [8]

Reproduction

Comb ducks nest mainly in tree holes, [3] also in tall grass. They line their nests with reeds, grass, or feathers, but not down. [8]

Males may have two mates at once or up to five in succession. They defend the females and young, but not the nest sites. Unmated males perch in trees and wait for opportunities to mate. [8]

Females lay seven to 15 [3] yellowish-white eggs. Several females may lay in a single "dump nest" containing up to 50 eggs. [8]

Related Research Articles

<span class="mw-page-title-main">Anatidae</span> Biological family of water birds

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, floating on the water surface, and in some cases diving in at least shallow water. The family contains around 174 species in 43 genera.

<span class="mw-page-title-main">Anatinae</span> Subfamily of birds

The Anatinae are a subfamily of the family Anatidae. Its surviving members are the dabbling ducks, which feed mainly at the surface rather than by diving. The other members of the Anatinae are the extinct moa-nalo, a young but highly apomorphic lineage derived from the dabbling ducks.

<span class="mw-page-title-main">Northern pintail</span> Migratory duck that breeds in northern Eurasia and North America

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.

<span class="mw-page-title-main">Tadorninae</span> Subfamily of birds

The Tadorninae is the shelduck-sheldgoose subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans.

<span class="mw-page-title-main">Gadwall</span> Species of bird

The gadwall is a common and widespread dabbling duck in the family Anatidae.

The term perching ducks is used colloquially to mean any species of ducks distinguished by their readiness to perch high in trees

<span class="mw-page-title-main">Eurasian teal</span> Species of bird (duck)

The Eurasian teal, common teal, or Eurasian green-winged teal is a common and widespread duck that breeds in temperate Eurosiberia and migrates south in winter. The Eurasian teal is often called simply the teal due to being the only one of these small dabbling ducks in much of its range. The bird gives its name to the blue-green colour teal.

<span class="mw-page-title-main">Wood duck</span> Species of bird

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.

<span class="mw-page-title-main">Muscovy duck</span> Species of bird

The Muscovy duck is a duck native to the Americas, from the Rio Grande Valley of Texas and Mexico south to Argentina and Uruguay. Feral Muscovy ducks are found in New Zealand, Australia, and in Central and Eastern Europe. Small wild and feral breeding populations have also established themselves in the United States, particularly in Florida, Louisiana, Massachusetts, the Big Island of Hawaii, as well as in many other parts of North America, including southern Canada.

<span class="mw-page-title-main">Knob-billed duck</span> Species of bird

The knob-billed duck, or African comb duck, is a type of duck found along the tropical/sub-tropical wetlands and waterways of Sub-Saharan Africa and the island of Madagascar, as well as most of South Asia and mainland Indochina.

<i>Aix</i> (bird) Genus of birds

Aix is a bird genus that contains two species of ducks: the wood duck, and the Mandarin duck. Aix is an Ancient Greek word used by Aristotle to refer to an unknown diving bird.

<span class="mw-page-title-main">Australian wood duck</span> Species of bird

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.

<span class="mw-page-title-main">Blue-winged goose</span> Species of bird

The blue-winged goose is a waterfowl species which is endemic to Ethiopia. It is the only member of the genus Cyanochen.

<span class="mw-page-title-main">Black-bellied whistling duck</span> Species of bird

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.

<span class="mw-page-title-main">Flying steamer duck</span> Species of bird

The flying steamer duck, also known as the flying steamer-duck or flying steamerduck, is a species of South American duck in the family Anatidae.

<span class="mw-page-title-main">Yellow-billed teal</span> Species of bird

The yellow-billed teal is a South American species of duck. Like other teals, it belongs to the diverse genus Anas; more precisely it is one of the "true" teals of subgenus Nettion. It occurs in Argentina, the Falkland Islands, Chile, Peru, Bolivia, Uruguay, and Brazil. It has also established itself in South Georgia, where it was first recorded breeding in 1971, and has been recorded as far east as Tristan da Cunha. It inhabits freshwater wetlands, preferring palustrine habitat to rivers. Considering its wide range and local abundance, it is not considered threatened by the IUCN.

<span class="mw-page-title-main">White-winged duck</span> Species of bird

The white-winged duck or white-winged wood duck is a large species of duck, formerly placed in the genus Cairina with the Muscovy duck and allied with the dabbling ducks. However, mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequence analysis indicate that the anatomical similarity to the Muscovy duck is deceiving and that the species is appropriately placed in a monotypic genus, as Asarcornis scutulata, which is evolutionarily closer to the redhead.

<span class="mw-page-title-main">Ringed teal</span> Species of bird

The ringed teal is a small duck of South American forests. It is the only species of the genus Callonetta. Usually placed with the dabbling ducks (Anatinae), this species may actually be closer to shelducks and belong in the subfamily Tadorninae; its closest relative is possibly the maned duck.

<span class="mw-page-title-main">Southern screamer</span> Species of bird

The southern screamer is a species of bird in family Anhimidae of the waterfowl order Anseriformes. It is found in Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay.

<span class="mw-page-title-main">Crested duck</span> Species of duck native to South America

The crested duck or South American crested duck is a species of duck native to South America, belonging to the monotypic genus Lophonetta. It is sometimes included in Anas, but it belongs to a South American clade that diverged early in dabbling duck evolution. There are two subspecies: L. specularioides alticola and L. specularioides specularioides. The Patagonian crested duck is also called the southern crested duck and its range lies in the Falklands, Chile, and Argentina.

References

  1. BirdLife International (2016). "Sarkidiornis sylvicola". IUCN Red List of Threatened Species . 2016: e.T22724744A94877265. doi: 10.2305/IUCN.UK.2016-3.RLTS.T22724744A94877265.en . Retrieved 19 November 2021.
  2. Bencke, Glayson Ariel (2007): Avifauna atual do Rio Grande do Sul, Brasil: aspectos biogeográficos e distribucionais ["The Recent avifauna of Rio Grande do Sul: Biogeographical and distributional aspects"]. Talk held on 22 June 2007 at Quaternário do RS: integrando conhecimento, Canoas, Rio Grande do Sul, Brazil. PDF abstract
  3. 1 2 3 4 5 6 Madge, Steve & Burn, Hilary (1987): Wildfowl: an identification guide to the ducks, geese and swans of the world. Christopher Helm, London. ISBN   0-7470-2201-1
  4. Johnson, Kevin P.; Sorenson, Michael D. (1999). "Phylogeny and biogeography of dabbling ducks (genus: Anas): a comparison of molecular and morphological evidence" (PDF). Auk . 116 (3): 792–805. doi:10.2307/4089339. JSTOR   4089339.
  5. Ogilvie & Young, Wildfowl of the World. New Holland Publishers (2004), ISBN   978-1-84330-328-2
  6. Hilty, Steven L. (2002). Birds of Venezuela. Princeton University Press. pp. 197–. ISBN   978-1-4008-3409-9.
  7. Sarkidiornis melanotos (Comb duck, Knob-billed duck). biodiversityexplorer.org
  8. 1 2 3 4 Honolulu Zoo (2007): Comb Duck Archived 2005-11-25 at the Wayback Machine . Retrieved 2007-06-08.