Yellow-billed Teal (Anas flavirostris)

Yellow-billed Teal

[order] ANSERIFORMES | [family] Anatidae | [latin] Anas flavirostris | [authority] Vieillot, 1816 | [UK] Yellow-billed Teal | [FR] Sarcelle a bec jaune | [DE] Andenente | [ES] Pato Barcino (Arg, Uy, Bo) | [NL] Chileense Taling | [copyright picture] Falkland Islands Tourist Board


Monotypic species


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 Yellow-billed Teal is a common duck of southern South America. The species shows the compact proportions typical of teal and is gray below and brown above with a dark brown head and yellow bill. Overall Yellow-billed Teal look like a darker, smaller and less elegant version of the widely sympatric Yellow-billed Pintail. Birds from the high altiplano are pale silvery below, whereas the lowland race is darker grayish brown.

Listen to the sound of Yellow-billed Teal

[audio: Teal.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 35 cm size max.: 45 cm
incubation min.: 22 days incubation max.: 26 days
fledging min.: 42 days fledging max.: 50 days
broods: 1   eggs min.: 5  
      eggs max.: 8  


South America : West, South. It occurs in Argentina, the Falkland Islands, Chile, Peru, Bolivia, Uruguay, and Brazil. It has also established itself in South Georgia


Freshwater lakes, ponds, rivers, marshes, wooded swamps usually high altitude; coastal areas in winter


Breeding offset with geographical variation: begin February/ March in Colombia, November and December Peru to north Argentina, late August to September further south in Chile, August in Venezuela. May double-brood in the north (lower latitudes). Nest is built near water, in thick vegetation, in large forks of trees, using Monk parakeet stick-nests, and holes in banks; also nest under house roofs. This species breeds solitary or in loose groups. Clutch size is 5-8 eggs which are incubated by the female for about 25 days. Young fledge after another 6-7 weeks, male will assist female in rearing the brood.

Feeding habits

Forages by dabbling, head-dip and up-end in shallow, also walks along water?s edge filtering mud, and occasionally dives. Diet consists of small invertebrates (insects, crustaceans, amphipods), plus seeds and vegetative parts aquatic plants, and in winter rotting kelp and seeds of pig vine.

Video Yellow-billed Teal


copyright: Josep del Hoyo


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.
Yellow-billed Teal status Least Concern


High latitude (southernmost) populations migrate as far north as Uruguay, Paraguay, southern Brazil. Andean populations may move to lower altitudes. Island populations sedentary

Distribution map

Yellow-billed Teal distribution range map

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