Red-billed Duck (Anas erythrorhyncha)

Red-billed Duck

[order] ANSERIFORMES | [family] Anatidae | [latin] Anas erythrorhyncha | [authority] Gmelin, 1789 | [UK] Red-billed Duck | [FR] Canard a bec rouge | [DE] Rotschnabel-Ente | [ES] anade Piquirrojo | [NL] Roodsnavelpijlstaart

Subspecies

Genus Species subspecies Region Range
Anas erythrorhyncha AF e, sc, s

Genus

Anas is a genus of dabbling ducks. It includes mallards, wigeons, teals, pintails and shovelers in a number of subgenera. Some authorities prefer to elevate the subgenera to genus rank.[1] Indeed, as the moa-nalos are very close to this clade and may have evolved later than some of these lineages, it is rather the absence of a thorough review than lack of necessity that this genus is rather over-lumped. The phylogeny of this genus is one of the most confounded ones of all living birds. Research is hampered by the fact the radiation of the two major groups of Anas ? the teals and mallard groups ? took place in a very short time and fairly recently, roughly in the mid-late Pleistocene. Furthermore, hybridization may have long played a major role in Anas evolution, with within-subgenus hybrids regularly and between-subgenus hybrids not infrequently being fully fertile.[1] The relationships between species are much obscured by this fact, and mtDNA sequence data is of dubious value in resolving their relationships; on the other hand, nuclear DNA sequences evolve too slowly to resolve the phylogeny of the subgenus Anas for example. Some major clades can be discerned. For example, that the traditional subgenus Anas, the mallard group, forms a monophyletic (in the loose sense, i.e. non-holophyletic) group has never been seriously questioned by modern science and is as good as confirmed (but see below). On the other hand, the phylogeny of the teals is very confusing. For these reasons, the dabbling duck lineages more distantly related to mallard group (which includes the type species of Anas) than the wigeons should arguably be separated in their own genera. These would include the Baikal Teal, the Garganey, the spotted black-capped Punanetta group, and the shovelers and other blue-winged species. Whether the wigeons, which are very distinct in morphology and behavior, but much less so in mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequences, should also be considered a distinct genus Mareca (including the Gadwall and Falcated Duck) is essentially the one remaining point of dispute as regards the question which taxa should remain in this genus and which ones should not.

Physical charateristics

The Red-billed Teal is 43?48 centimetres (17?19 in) long and has a blackish cap and nape, contrasting pale face, and bright red bill. The body plumage is a dull dark brown scalloped with white. Flight reveals that the secondary flight feathers are buff with a black stripe across them. The sexes are similar, but juveniles are duller than adults.


wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 43 cm size max.: 48 cm
incubation min.: 25 days incubation max.: 28 days
fledging min.: 53 days fledging max.: 60 days
broods: 1   eggs min.: 5  
      eggs max.: 12  

Range

Africa : East, Southcentral, South. S Sudan and Ethiopia S to Cape Province and W to Angola; Madagascar.

Habitat

Red-billed Teal feed in shallow water and are often found near temporary pools and flooded land.

Reproduction

The Red-billed Duck breeds mainly in the summer months, but season may vary according to the water level. Usually breeding starts after the main rain season. Pair bonds can last for long time, but not always. Male sometimes helps female to guard the chicks. Nest is on the ground, concealed among the dense waterside vegetation. Nest depression is lined with grass. Female lays between 5 and 12 eggs, and the incubation lasts about 25 to 28 days. Young fledge two months later.

Feeding habits

It feeds by dabbling for plant food, or foraging on land mainly in the evening or at night. It will take seedss, fruit, grains, roots andsoft plant matter. Also invertebrates, usually molluscs; insects and crustaceans. It grazes on land, headdips in water and will visit fields of stubble.

Video Red-billed Duck

httpv://www.youtube.com/watch?v=E1ON2I4MMhI

copyright: Josef del Hoyo


Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Red-billed Duck status Least Concern

Migration

Usually sedentary but disperses after the breeding season, which varies along with rainfall and flooding.

Distribution map

Red-billed Duck distribution range map

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