Hawaiian Duck vs Wandering Whistling-duck
Anas wyvilliana compared with Dendrocygna arcuata
Side-by-Side Comparison
| Attribute | Hawaiian Duck | Wandering Whistling-duck |
|---|---|---|
| Scientific Name | Anas wyvilliana | Dendrocygna arcuata |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Vulnerable | Least Concern |
| Length | — | — |
| Wingspan | 44.0 cm (17.3 in) | 37.2 cm (14.6 in) |
| Weight | 573.25 g (20.22 oz) | 779.5 g (27.50 oz) |
| Diet | Fish-diving duck of South American rivers; uses serrated bill to catch fish and aquatic invertebrates; … | Eats grasses, sedges, and aquatic plants in tundra; winter diet of coastal salt marsh grasses … |
| Clutch Size | 9-13 | 6-15 |
| Population Trend | — | — |
Habitat Comparison
Hawaiian Duck
Freshwater marshes, rivers, reservoirs, and taro fields on Kauai and other Hawaiian islands. Nests in dense vegetation near water. Threatened by hybridization with domestic or feral Mallards.
Wandering Whistling-duck
Tropical freshwater marshes, flooded grasslands, swamps, and lake margins from the Philippines and Indonesia through Papua New Guinea to northern and eastern Australia. Nomadic following wet season flooding.
Song & Call Comparison
Hawaiian Duck
Female produces a raspy, descending quacking series; male gives a soft, nasal sound. Calls similar to Mallard but higher-pitched; alarm is a rapid-fire quacking rattle.
Wandering Whistling-duck
A soft whistle 'whi-whi-whi' in flight. Less vocal than other whistling-ducks; flocks tend to be quieter. Given at dawn and dusk during flight to roosting or feeding areas.
Geographic Range & Migration
Hawaiian Duck
Ranges across sub-Saharan Africa in open grasslands and wetland edges. Locally nomadic following seasonal rainfall patterns.
Wandering Whistling-duck
Breeds in Arctic and subarctic regions; winters at sea around the Antarctic pack ice, one of the longest migrations known.
Conservation Status
Hawaiian Duck
Wandering Whistling-duck
How to Tell Them Apart
Hawaiian Duck
Mottled brown plumage; males may show slight green gloss on head but reduced compared to Mallard. Iridescent blue-purple speculum with white borders. Orange bill. Females similar to males; pale buff …
Wandering Whistling-duck
Rich chestnut-brown head and neck; dark brown back. Flanks rufous with pale buff streaks and dark spots. Belly blackish. Long, dark pinkish legs. Upright posture typical of whistling-ducks. Sexes similar.
About These Birds
Hawaiian Duck
A medium-sized duck resembling a female Mallard, with mottled brown plumage and green speculum. Endemic to Hawaii; hybridizes with feral Mallards, threatening its genetic integrity. Found on freshwater wetlands of Kauai and other islands. Endangered; conservation focus on reducing hybridization.
Wandering Whistling-duck
A medium-sized whistling-duck with rufous-brown body, dark brown back, pale buff underparts, and a chestnut collar. Found in tropical wetlands from Indonesia to Australia and Pacific islands. Highly social and nomadic. Forages by dabbling and diving in shallow freshwater.