Orinoco goose

Appearance

Orinoco geese are typically 61 to 76 cm long. They have pale heads and necks, chestnut flanks and mantles and blackish wings with white speculae. Their legs are red, their bills black and pinkish. The sexes are identical in plumage, though the males are larger; juveniles have duller plumage.

Males have high pitched whistling calls, and females cackle like the related Egyptian goose.

Naming

Based on a molecular phylogenetic study published in 2014, some authorities place this species together with the Andean goose in the resurrected genus "Oressochen".

Distribution

The Orinoco are resident breeders in the forests of tropical South America. Largely terrestrial, they also perch readily in trees. They rarely swim or fly, unless hard-pressed. In flight, they look heavy, more like geese than ducks, hence the English name. They prefer forest lakes or marshes with access to open woodland or savanna, or beaches with direct access to river channels. They are more rarely seen in tributary areas.

Orinoco geese have escaped or been deliberately released into Florida, where there is no evidence they breed, persisting rather due to continual releases and escapes.

Status

In order to protect these birds, conservation efforts focus on river margins, sandy beaches along the main river channel and migration routes.

Habitat

The Orinoco are resident breeders in the forests of tropical South America. Largely terrestrial, they also perch readily in trees. They rarely swim or fly, unless hard-pressed. In flight, they look heavy, more like geese than ducks, hence the English name. They prefer forest lakes or marshes with access to open woodland or savanna, or beaches with direct access to river channels. They are more rarely seen in tributary areas.

Orinoco geese have escaped or been deliberately released into Florida, where there is no evidence they breed, persisting rather due to continual releases and escapes.

Migration

The Orinoco geese are very territorial in the breeding season, and usually nest in hollow trees, only occasionally on the ground. Manú National Park in Peru is known to have an established population, of particular interest for its disappearance during the wet season. Roughly 12% of the Manú National Park Orinoco geese migrate during the wet season after breeding during the dry season. They were found to migrate to the Llanos de Moxos in Bolivia, with movements of over five kilometres undertaken at night. The pattern indicates they move mostly longitudinally, and that partial migration plays an important role, maybe showing the evolutionary transition from sedentariness to complete migration.

The migration of Orinoco geese may also 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, leading to the contamination of nearby food.