Brazilian Merganser vs African Pygmy-goose
Mergus octosetaceus compared with Nettapus auritus
Side-by-Side Comparison
| Attribute | Brazilian Merganser | African Pygmy-goose |
|---|---|---|
| Scientific Name | Mergus octosetaceus | Nettapus auritus |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Critically Endangered | Least Concern |
| Length | — | — |
| Wingspan | 39.2 cm (15.4 in) | 29.9 cm (11.8 in) |
| Weight | 827.6666666666666 g (29.20 oz) | 272.5 g (9.61 oz) |
| Diet | Dives for small fish in fast-flowing South American rivers. Critically endangered; uses serrated bill to … | Filter-feeds on invertebrates and seeds; dabbles in shallow ponds; diet more plant-based outside spring breeding … |
| Clutch Size | 5-8 | 6-12 |
| Population Trend | — | — |
Habitat Comparison
African Pygmy-goose
Freshwater lakes, ponds, and rivers with floating water lilies and other aquatic vegetation across sub-Saharan Africa from Senegal to Tanzania. Nests in tree cavities near water. Highly dependent on water lily vegetation.
Song & Call Comparison
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.
African Pygmy-goose
Male produces a soft, wheezy whistle; female gives a quiet, duck-like quack. Pairs exchange rapid twittering notes during courtship on lily-covered African pools.
Geographic Range & Migration
Brazilian Merganser
Critically endangered; restricted to a few rivers in southern Brazil, Argentina, and Paraguay. Found on fast-flowing rivers in Atlantic Forest.
African Pygmy-goose
Breeds across temperate to sub-Arctic Eurasia; winters in Africa, South Asia, and Southeast Asia.
Conservation Status
Brazilian Merganser
African Pygmy-goose
How to Tell Them Apart
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.
African Pygmy-goose
Tiny. Males have glossy dark green head with orange facial patch and ear spot; chestnut-orange flanks; white underparts; black and green back. Females duller with dark eye-stripe. Small yellow-green bill.
About These Birds
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.
African Pygmy-goose
A tiny jewel-like duck—one of Africa's smallest waterfowl. Males have iridescent green-and-white plumage, an orange bill, and a dark green cap; females are mottled brown. Found on lily-covered lakes in sub-Saharan Africa. Perches on water lily pads and feeds on their seeds and flowers.