[order] ANSERIFORMES | [family] Anatidae | [latin] Chloephaga poliocephala | [authority] Sclater, 1857 | [UK] Ashy-headed Goose | [FR] Ouette a tete grise | [DE] Graukopf-Gans | [ES] Cauquen Real/Cabecigris (Arg) | [NL] Grijskopgans
Subspecies
| Genus | Species | subspecies | Region | Range |
| Chloephaga | poliocephala | SA | Southern Cone |
Genus
The sheldgeese are a genus (Chloephaga) of 5 species in the family Anatidae. It belongs to the tribe Tadornini, A group that resembles true geese and shows similar habits but is more closely related to shelducks and ducks. One of the most interesting aspects of the closely knit group of the genus Chloephaga is the great variation in colouration between the species and sexes, ranging from nearly no dimorphism in the Andean goose. All Chloephaga share upper white upper wing coverts, a metallic speculum on the secondary coverts and white secondaries. The voice of the males of these species is a whistle and that of the females a cackle. They also share short, high bills and a semiterrestrial lifestyle.
Physical charateristics
This rather small sheldgoose is essentially tricolored, in both sexes, with a gray head (whitish eye-ring), a chestnut breast, and white sides and abdomen overlaid with vertical black barring. The rump and tail are black and the under tail coverts pale chestnut, while the mantle is brown. The bill is black, and the legs and feet are two-toned orange and black. The wings are as in the other species, with white secondaries and iridescent green secondary coverts, the other coverts being white. Females are smaller and have somewhat barred breasts, and immature birds are more extensively brownish and have brown rather than iridescent coverts. In the field, this species is most likely to be confused with the ruddy-headed sheldgoose, but the grayish head color and pure white abdomen will serve to identify it. The calls of all sheldgeese are similar, consisting of repeated whistling notes in the males and grating calls by the females.
Listen to the sound of Ashy-headed Goose
[audio:http://www.planetofbirds.com/MASTER/ANSERIFORMES/Anatidae/sounds/Ashy-headed Goose.mp3]
Copyright remark: Most sounds derived from xeno-canto
recorded by Bernabe Lopez-Lanus
| wingspan min.: | 0 | cm | wingspan max.: | 0 | cm |
| size min.: | 50 | cm | size max.: | 60 | cm |
| incubation min.: | 28 | days | incubation max.: | 32 | days |
| fledging min.: | 0 | days | fledging max.: | 0 | days |
| broods: | 1 | eggs min.: | 4 | ||
| eggs max.: | 6 |
Range
South America : Southern Cone
Habitat
It is found in the forested areas of the extreme south of South America in wooded swamps and wetlands close to the Nothofagus beech forests.
Reproduction
The abundantly lined -with down- nest is built in tall grass or tree-hollow. 4?6 eggs are laid which are incubated by the female only for about a month.
Feeding habits
Although the ashy-headed sheldgoose often associates with the open-country Magellan goose, it is relatively scarce where that species is most common, and is far more prevalent in wooded areas. In mountains it is most closely associated with swampy areas where rushes and associated plants occur amid small clearings in the forest (Johnson, 1965). Unlike the other Chloephaga sheldgeese, these birds perch readily in trees and normally nest among them. Since they often feed in company with Magellan geese, they presumably eat much the same grassy foods.
Video Ashy-headed Goose
httpv://www.youtube.com/watch?v=EwoKY3pV2Fk
copyright: German Pugnali
Conservation
This species has a very 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 may be moderately small to large, but it is not believed to 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.
The relatively few descriptions of this bird in the wild indicate that it is usually to be found in small flocks outside the breeding season. Flock sizes of up to as many as 200 birds have been recorded. In southern Chile it is probably most abundant in the vicinity of Chiloe and the Guaitecas Islands to the south, becoming rare in the open grasslands of northern Tierra del Fuego and the southern part of Magellanes. It presumably breeds at two or three years of age.
The relatively few descriptions of this bird in the wild indicate that it is usually to be found in small flocks outside the breeding season. Flock sizes of up to as many as 200 birds have been recorded. In southern Chile it is probably most abundant in the vicinity of Chiloe and the Guaitecas Islands to the south, becoming rare in the open grasslands of northern Tierra del Fuego and the southern part of Magellanes. It presumably breeds at two or three years of age.
Migration
Partially migratory, moves North to winter in the Pampas in the Buenos Aires region. Has straggled to the Falklands.
Distribution map
