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 i ...

in tribe Tadornini of subfamily

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

. It is found in

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

, and the

Falkland Islands The Falkland Islands (; ), commonly referred to as The Falklands, 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 from Cape Dub ...

.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 "unisp ...

Description

The ruddy-headed goose is long. Males weigh and females . Adults have the same

plumage Plumage () is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can b ...

. 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, is the largest and most populous Provinces of Argentina, Argentine province. It takes its name from the city of Buenos Aires, the capital of the country, which used to be part of the province an ...

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

Pampas The Pampas (; from Quechua 'plain'), also known as the Pampas 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 o ...

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) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

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 Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

by the

South American gray fox The South American gray fox (''Lycalopex griseus''), also known as the Patagonian fox, the ''chilla'' or ''zorro gris'' (gray fox or gray zorro), is a South America, South American species of ''Lycalopex'' (the "false" or lesser foxes) in the Ca ...

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

rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...

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.