The ruddy-headed goose (''Chloephaga rubidiceps'') is a species of

waterfowl Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae, the largest family, which in ...

in tribe Tadornini of subfamily

Anserinae The Anserinae are a subfamily in the waterfowl family Anatidae. It includes the swans and true geese. Under alternative systematical concepts (see e.g., Terres & NAS, 1991), it is split into two subfamilies, the Anserinae contain the geese and ...

. It is found in

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, and the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouzet ...

.HBW and BirdLife International (2021) Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip retrieved August 7, 2022

Taxonomy and systematics

The ruddy-headed goose is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

Description

The ruddy-headed goose is long. Males weigh and females . Adults have the same plumage. Their heads and necks are red-brown, their back, breast, and flanks gray and buff with brown barring, their belly cinnamon, and their tail black. Their wing's upperside is gray and the underside gray, black, and white. Their bill is black and the legs and feet orange with black markings. Juveniles are similar to adults but duller overall.Carboneras, C. and G. M. Kirwan (2020). Ruddy-headed Goose (''Chloephaga rubidiceps''), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.ruhgoo1.01 retrieved September 29, 2022

Distribution and habitat

The ruddy-headed goose is found in the eastern Chilean and Argentinian parts of Tierra del Fuego and north from there to

Buenos Aires Province Buenos Aires (), officially the Buenos Aires Province (''Provincia de Buenos Aires'' ), is the largest and most populous Argentine province. It takes its name from the city of Buenos Aires, the capital of the country, which used to be part of th ...

, Argentina. It is also found on the Falkland Islands. It inhabits open landscapes such as meadows,

Pampas The Pampas (from the qu, pampa, meaning "plain") are fertile South American low grasslands that cover more than and include the Argentine provinces of Buenos Aires, La Pampa, Santa Fe, Entre Ríos, and Córdoba; all of Uruguay; and Brazil ...

wetlands, the borders of ponds, and coastal grasslands.

Behavior

Movement

Ruddy-headed geese are year-round residents of the Falkland Islands, though they make local movements there. The species nests in Tierra del Fuego and far southern mainland Argentina and for the winter migrates north from there as far as Argentina's Buenos Aires Province.

Feeding

The ruddy-headed goose is almost entirely vegetarian and feeds mostly on the ground rather than in water. On the breeding grounds its diet is small berries and the roots, leaves, stems, and seeds of grasses and sedges. During winter it feeds on young wheat and in harvested fields of maize, sunflower, and sorghum.

Breeding

The ruddy-headed goose's breeding season begins as early as September on the Falkland Islands and in mid-October on the mainland. It nests singly or in small loose groups. Nests are placed in long grass or amid boulders and are lined with down. The clutch size is three to eight eggs. Males guard females during the incubation period of about 30 days. The time to fledging is not known.

Vocalization

Male and female ruddy-headed geese have different vocalizations: Males make a "short, whistled 'seep'" and females a "short rasping quack".

Status

The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed the ruddy-headed goose as being of Least Concern, though its population size is unknown and believed to be decreasing. The population in the Falklands appears robust but that in Tierra del Fuego and mainland South America may be only a few hundred birds after major decline in the 20th century. A major cause of the crash is predation by the

South American gray fox The South American gray fox (''Lycalopex griseus''), also known as the Patagonian fox, the chilla or the gray zorro, is a species of ''Lycalopex'', the "false" foxes. It is endemic to the southern part of South America. Description The South A ...

, which was introduced to Tierra del Fuego in the 1950s to control

rabbit Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit speci ...

s. A Memorandum of Understanding was negotiated in 2006 with Argentina and Chile under the

Bonn Convention The Convention on the Conservation of Migratory Species of Wild Animals, also known as the Convention on Migratory Species (CMS) or the Bonn Convention, is an international agreement that aims to conserve migratory species throughout their r ...

in an attempt to safeguard the remaining migratory Tierra del Fuego/mainland population.