Wandering Whistling-duck vs Brazilian Merganser
Dendrocygna arcuata compared with Mergus octosetaceus
Side-by-Side Comparison
| Attribute | Wandering Whistling-duck | Brazilian Merganser |
|---|---|---|
| Scientific Name | Dendrocygna arcuata | Mergus octosetaceus |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Critically Endangered |
| Length | — | — |
| Wingspan | 37.2 cm (14.6 in) | 39.2 cm (15.4 in) |
| Weight | 779.5 g (27.50 oz) | 827.6666666666666 g (29.20 oz) |
| Diet | Eats grasses, sedges, and aquatic plants in tundra; winter diet of coastal salt marsh grasses … | Dives for small fish in fast-flowing South American rivers. Critically endangered; uses serrated bill to … |
| Clutch Size | 6-15 | 5-8 |
| Population Trend | — | — |
Habitat Comparison
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
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.
Brazilian Merganser
Male produces a harsh, rasping call; female gives a guttural, grunting series. Critically endangered; quiet vocalizations suit its secretive lifestyle in fast-flowing Brazilian mountain rivers.
Geographic Range & Migration
Wandering Whistling-duck
Breeds in Arctic and subarctic regions; winters at sea around the Antarctic pack ice, one of the longest migrations known.
Brazilian Merganser
Critically endangered; restricted to a few rivers in southern Brazil, Argentina, and Paraguay. Found on fast-flowing rivers in Atlantic Forest.
Conservation Status
Wandering Whistling-duck
Brazilian Merganser
How to Tell Them Apart
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.
Brazilian Merganser
Male has dark glossy greenish-black head with long shaggy crest; finely vermiculated grey body, white wing patch. Female similar but with rufous-chestnut wash on head and shorter crest.
About These Birds
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.
Brazilian Merganser
One of the world's rarest waterfowl (~830 g), family Anatidae, with a serrated bill and dark green head with bushy crest. Inhabits fast-flowing clear rivers in the Atlantic Forest of Brazil, Argentina, and Paraguay. Feeds on fish and aquatic invertebrates. Critically Endangered; fewer than 250 mature individuals remain due to dam construction and river degradation.