Chiloe Wigeon (Anas sibilatrix)

Chiloe Wigeon

[order] ANSERIFORMES | [family] Anatidae | [latin] Anas sibilatrix | [authority] Poeppig, 1829 | [UK] Chiloe Wigeon | [FR] Canard de Chile | [DE] Chile-Pfeifente | [ES] Pato Ovejero (Arg, Bo, Uy), Silbon Overo | [NL] Chileense Smient


Genus Species subspecies Region Range
Anas sibilatrix SA Southern Cone


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 male is iridescent green on the sides of the head, high crown and small black bill. It has Whitish cheeks and forehead with a black tail. Female is similar to male with less green iridescence.

Listen to the sound of Chiloe Wigeon

[audio: Wigeon.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 43 cm size max.: 54 cm
incubation min.: 24 days incubation max.: 26 days
fledging min.: 45 days fledging max.: 54 days
broods: 1   eggs min.: 5  
      eggs max.: 8  


South America : Southern Cone


The Chiloe Wigeon is most likely to be found on lakes, lagoons, slow-flowing rivers and other bodies of freshwater.


Breeding season begins with mutual displays of chin-lifting movements and vocalizations. Both the male and female frequently display preening behaviors and the male will regularly turn his head as he swims ahead of his mate. Even in flocks of 100, strong pair bonds can form during this time. Chiloe wigeons have the strongest pair bonds of all wigeons. The female will seek out a nesting site in tall grasses or weeds. The male does not assist in incubation but remains nearby protecting the nest. He will rejoin his mate after the ducklings hatch and attend to the young. Clutch size is 5-8 eggs which are incubated for about 25 days. The young fledge after another 7 weeks.

Feeding habits

Like other dabbling ducks, the Chiloe Wigeon feeds on aquatic vegetation from the surface of the water by head-dipping and upending; it also will graze from land.

Video Chiloe Wigeon


copyright: German Pugnali


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). The population trend appears to be stable, and hence the species does not 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.
Although the Chiloe wigeon is a common species, especially in parts of Chile, hunting pressure and loss of habitat have affected their numbers.
Chiloe Wigeon status Least Concern


The Chiloe Wigeon is generally a sedentary species; however, the individuals that breed in the southern most portions of South America do exhibit short-range migratory patterns to central South America.

Distribution map

Chiloe Wigeon distribution range map

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