The Orinoco goose (''Neochen jubata'') is a Near Threatened species of waterfowl 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 ...

.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 It is found in every mainland South American country except Chile, French Guiana,

Suriname Suriname (; srn, Sranankondre or ), officially the Republic of Suriname ( nl, Republiek Suriname , srn, Ripolik fu Sranan), is a country on the northeastern Atlantic coast of South America. It is bordered by the Atlantic Ocean to the north ...

, and Uruguay.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 24 July 2022. Species Lists of Birds for South American Countries and Territories. https://www.museum.lsu.edu/~Remsen/SACCCountryLists.htm retrieved July 24, 2022

Taxonomy and systematics

The Orinoco goose's taxonomy is unsettled. The International Ornithological Committee (IOC) and

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

's ''

Handbook of the Birds of the World The ''Handbook of the Birds of the World'' (HBW) is a multi-volume series produced by the Spanish publishing house Lynx Edicions in partnership with BirdLife International. It is the first handbook to cover every known living species of bird. T ...

'' (HBW) place it alone in genus ''Neochen''. However, based on a

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study published in 2014, the South American Classification Committee of the American Ornithological Society and the

Clements taxonomy ''The Clements Checklist of Birds of the World'' is a book by Jim Clements which presents a list of the bird species of the world. The most recent printed version is the sixth edition (2007), but has been updated yearly, the last version in 2022 ...

place it and the Andean goose in the resurrected genus ''Oressochen''. The IOC and HBW place the Andean goose in genus ''Chloephaga''. Two fossil relatives have been described from Pleistocene sites in South America, '' Neochen pugil'' and '' N. debilis''.Davenport, L., W. Endo, and K. Kriese (2020). Orinoco Goose (''Oressochen jubatus''), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.origoo1.01 retrieved September 28, 2022 The Orinoco goose is monotypic.

Description

The Orinoco goose is long. Males weigh about and females about . Adult males have an off-white head, neck, and breast with slight buffy streaks on the nape and buffy scalloping on the breast. Their

mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...

is gray with white scalloping. They have an orange band across the upper mantle and onto the sides of the breast and flanks and a crescent of dark brown behind the flanks. Their undertail

coverts A covert feather or tectrix on a bird is one of a set of feathers, called coverts (or ''tectrices''), which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail. Ear coverts The ear coverts are sm ...

are white. Their wings are black with a wide white speculum. Their bill has a black maxilla and a mostly red mandible and their legs and feet are bright salmon red. Adult females have a similar pattern as the male, but have a drab wash on their crown and nape, less orange on the flanks, and darker scalloping on the sides of the belly. Their legs and feet are more a dull orange than bright red.

Distribution and habitat

The Orinoco goose is found from Venezuela south through Colombia, eastern Ecuador, eastern Peru, and Bolivia into far northern Argentina and in a broad swath across central Brazil. An isolated population spans the northern Brazil-Guyana border. Though 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 ...

range map includes French Guiana, Suriname, and Paraguay, the South American Classification Committee of the American Ornithological Society has no records in the first two countries and records only as a

vagrant Vagrancy is the condition of homelessness without regular employment or income. Vagrants (also known as bums, vagabonds, rogues, tramps or drifters) usually live in poverty and support themselves by begging, scavenging, petty theft, temporar ...

in Paraguay. The Orinoco goose inhabits wet savanna and the edges of large freshwater wetlands in the wet season, and in the dry season is also found on river beaches and

oxbow lake An oxbow lake is a U-shaped lake or pool that forms when a wide meander of a river is cut off, creating a free-standing body of water. In South Texas, oxbows left by the Rio Grande are called '' resacas''. In Australia, oxbow lakes are call ...

s in the

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

Behavior

Migration

The Orinoco goose is a year-round resident of the

Llanos The Llanos (Spanish ''Los Llanos'', "The Plains"; ) is a vast tropical grassland plain situated to the east of the Andes in Colombia and Venezuela, in northwestern South America. It is an ecoregion of the tropical and subtropical grasslands, sav ...

of Venezuela and possibly Colombia. Some of the Bolivian population is also non-migratory. However, some leave the

Llanos de Moxos The Beni savanna, also known as the Llanos de Moxos or Moxos plains, is a tropical savanna ecoregion of the Beni Department of northern Bolivia. Setting The Beni savanna covers an area of in the lowlands of northern Bolivia, with small portio ...

to breed away in Manú National Park, Peru, and others move almost to along the Río Juruá in western Brazil. The migration pattern of other populations, or lack of it, are not known. The migration of Orinoco geese may spread disease. ''Toxoplasma gondii'' and ''Neospora caninum'' are both apicomplexan parasites that infect various animals and cause severe disease. They thrive in fields where Orinoco geese forage during stopovers during migration. Once birds are infected, they can transmit the parasites to other birds or humans. Orinoco goose meat is eaten by people in Bolivia and Brazil, potentially leading to human infection.

Feeding

The Orinoco goose is herbivorous and feeds mainly on leaves and seed heads, especially those of grasses. It also feeds on aquatic algae in stagnant water along rivers and oxbows. It mostly forages during the day in open areas near water, although it also forages at night. Individuals move between feeding and resting areas at dawn and dusk.

Breeding

The Ornico goose's breeding season varies geographically and with rainfall patterns. Populations below the Equator nest between April and November, a mostly dry season. In Venezuela most nest in the July to August wet season though some nest at other times. Orinoco geese nest in both natural and artificial cavities. They use cavities in trees formed by natural causes such as limb loss or rot rather than those created by other cavity nesting species, and may compete with owls and parrots for cavities. There are some reports of nesting on the ground in dense grass but that strategy appears rare. Orinoco geese are sometimes brood parasites, with a female laying eggs in another Orinoco goose's nest. In one study unparasitized nests had a clutch size averaging seven eggs and parasitized ones averaged about 19. Nest success as a percentage of the clutch was higher in parasitized nests. Orinoco geese form strong year-round pair bonds and are intensely territorial during the breeding season. Males guard females during the incubation period.

Vocalization

The Orinoco goose is very vocal. During the breeding season males make "a high whistle and guttural honks" and females "a loud cackle". Males also make "a shrill-whistled ''zree'' and series of hollow reedy whistles" and females "a low guttural honking ''gu'rump, gur'rump, gur'rump''". Both sexes make "a distinctive nasal honking, ''unnhh?''". Young make "soft chicken-like peeps".

Status

The

has assessed the Orinoco goose as Near Threatened. It has a large range but its estimated population of 10,000 to 25,000 mature individuals is decreasing "at a slow to moderate rate". The major cause of the decline appears to be hunting, because populations on unhunted protected areas are stable. Ongoing conversion of habitat to rice cultivation is another threat. Conservation efforts should focus on river margins, sandy beaches along main river channels, and migration routes.

References

External links

* * {{Taxonbar, from=Q905268 Orinoco goose Orinoco goose Birds of Venezuela Birds of the Guianas Birds of the Amazon Basin Orinoco goose Birds of Brazil