Family: Anatidae (Ducks, Geese, Swans)

Authority: (Vigors, 1834)

Red List Category

Criteria: D1

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Justification of Red List category
The overall population of this species has increased from a low of perhaps just 30 birds in the mid-1900s to over 2,000 individuals in 2011. The majority of the population outside Kaua'i does not breed successfully in the wild, so the effective population size is very small and consequently the species is listed as Vulnerable.

Population size: 250-999

Population trend: Increasing

Extent of occurrence (breeding/resident): 40,500 km²

Country endemic: Yes

Attributes
Land-mass type - oceanic island
Realm - Oceanic
IUCN Ecosystem -- Terrestrial biome