Hawaiian Duck illustration
Birdsong field guide

Hawaiian Duck

Anas wyvilliana

The Hawaiian Duck, or Koloa maoli, is a small, mottled brown dabbling duck endemic to the Hawaiian archipelago and closely related to the Mallard. It is a secretive, non-migratory species that lacks the flashy breeding plumage typically seen in its continental relatives.

What it sounds like

A quiet, soft quack similar to a Mallard's but generally higher-pitched and less frequently uttered.

Reference call, compare with what you heard
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Rec. Phoenix Birder · United StatesCC BY-NC-SAXeno-canto

Field notes

  • The species faces a critical threat of 'genetic extinction' due to extensive hybridization with introduced feral Mallards.
  • Unlike Mallards, sexual dimorphism is subtle; males are slightly larger and have olive-colored bills compared to the orange-and-black bills of females.
  • Kauaʻi supports the only remaining large, genetically pure population of Koloa maoli in the wild.
  • They are highly versatile foragers, consuming a diet of snails, dragonfly larvae, earthworms, and various aquatic seeds.
  • Historically found on all main islands, they were nearly driven to extinction by the 1960s before intensive conservation and reintroduction efforts began.
Habitat
Freshwater wetlands, taro patches, mountain streams, irrigation ditches, and high-elevation bogs.
Range
Endemic to the Hawaiian Islands; primarily Kauaʻi and Niʻihau, with reintroduced populations on Oʻahu, Maui, and Hawaiʻi Island.

Similar & commonly confused birds

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