Cauquén de Cabeza Gris

Identificación

The ashy-headed goose is 50 to 60 cm (20 to 24 in) long. Males weigh 1.62 to 2.27 kg (3.6 to 5.0 lb) and females 1.47 to 1.49 kg (3.2 to 3.3 lb). Adults have the same plumage. Their heads and necks are gray, their upper back and breast chestnut with fine barring, their flanks barred black and white, and their belly white. In flight their blackish wings show bold white leading and trailing patches and a metallic green speculum. Their bill is black and the legs and feet orange with black markings. Juveniles' rufous areas are much duller, their back and breast barring stronger, and their speculum dark brownish.

Taxonomía

The ashy-headed goose is monotypic.

Nombre científico

Chloephaga poliocephala

Autoridad

Sclater, PL, 1857

Orden

Anseriformes

Familia

Anátidos

Género

Chloephaga

Distribución y hábitat

The ashy-headed goose is a bird of South America's southern cone from central Chile and Buenos Aires Province, Argentina, south into Tierra del Fuego. It also occurs as vagrant on the Falkland Islands and has bred there. In summer it primarily inhabits clearings in damp forests of southern beech (Nothofagus sp.) around lakes and marshes, on inland islands, near the coast, and on higher ground. In winter it favors meadows and pastures.

Migración

Complete migrants

Comportamiento

The ashy-headed goose nests south of 37° south latitude in Chile and western Argentina. In winter much of the population moves further north in Chile and onto the Argentinian Pampas.<p>The ashy-headed goose is almost entirely vegetarian. A study of its diet on its wintering grounds in Argentina showed it feeding mainly in harvested fields of wheat, maize, sunflower, and sorghum. One in the austral summer in Tierra del Fuego showed a diet there of leaves and fleshy fruits. Red crowberry (Empetrum rubrum) was the dominant fruit.<p>The ashy-headed goose's breeding season begins in October to November and in some areas lasts to March. It nests singly or in small loose groups. Nests are placed in a tree hollow, on a stump, or in long grass, and are lined with down. The clutch size is four to six eggs. Males guard females during the incubation period of about 30 days. The time to fledging is not known.<p>Male and female ashy-headed geese have different vocalizations: Males make "soft, wigeon-like whistles" and females "harsh cackling notes".

Conservación

Tendencia poblacional

declining