Hawaiian Duck
Anas wyvilliana
A medium-sized duck, similar to female Mallard in appearance, but smaller and darker. Males lack the green head and curled black tail feathers of male Mallards. Both sexes have spotted tail feathers. The bill is dark greenish, with an orange tip in some females. Pure Hawaiian Ducks occur only on Kauai and montane streams and ponds on Hawaii Island. Most or all individuals on other islands are Mallard-Hawaiian Duck hybrids. Occurs in ponds, marshes, taro fields, and streams.
Identification
The Hawaiian duck (Anas wyvilliana) or koloa is a species of bird in the family Anatidae that is endemic to the large islands of Hawaiʻi. Taxonomically, the koloa is closely allied with the mallard (A. platyrhynchos). It differs in that it is monomorphic (with similarly marked males and females) and non-migratory. As with many duck species in the genus Anas, Hawaiian duck and mallards can interbreed and produce viable offspring, and the koloa has previously been considered an island subspecies of the mallard (Anas platyrhynchos). However, all major authorities now consider this form to be a distinct species within the mallard complex. Recent analyses indicate that this is a distinct species that arose through ancient hybridization between mallard and the Laysan duck (Anas laysanensis). The native Hawaiian name for this duck is koloa maoli (meaning "native duck"), or simply koloa. This species is listed as vulnerable by the IUCN Red List of Threatened Species, and its population trend is increasing.
Taxonomy
Genus: Anas; Family: Anatidae; Order: Anseriformes.
- Scientific name
- Anas wyvilliana
- Authority
- Sclater, PL, 1878
- Order
- Anseriformes
- Family
- Anatidae
- Genus
- Anas
Range and habitat
- Migration
- Resident species
Behavior
Migration pattern: Resident species.
Conservation
Population trend: rising.
- Population trend
- rising
Photos
Distribution
Bird Calls
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