Brazilian Merganser vs Mute Swan
Mergus octosetaceus compared with Cygnus olor
Side-by-Side Comparison
| Attribute | Brazilian Merganser | Mute Swan |
|---|---|---|
| Scientific Name | Mergus octosetaceus | Cygnus olor |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Critically Endangered | Least Concern |
| Length | — | 152.0 cm (59.8 in) |
| Wingspan | 39.2 cm (15.4 in) | 235.0 cm (92.5 in) |
| Weight | 827.6666666666666 g (29.20 oz) | 11000.0 g (388.01 oz) |
| Diet | Dives for small fish in fast-flowing South American rivers. Critically endangered; uses serrated bill to … | Submerged aquatic vegetation, algae, and grass. Feeds by upending in shallow water, reaching depths of … |
| Clutch Size | 5-8 | 5-7 |
| Population Trend | — | — |
Size Comparison
Habitat Comparison
Mute Swan
Lakes, slow rivers, estuaries, and coastal lagoons. Often associated with parks and ornamental waters in Europe.
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.
Mute Swan
Despite its name, not truly mute: gives hissing snorts and low grunting when threatened. Wings produce a loud rhythmic whistling throbbing sound in flight.
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.
Mute Swan
Native to Europe and western Asia. Introduced to North America, South Africa, Australia, and New Zealand.
Conservation Status
Brazilian Merganser
Mute Swan
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.
Mute Swan
All-white plumage in adults. Cygnets are grey-brown, gradually whitening over the first year. Graceful S-curved neck posture is distinctive.
Orange bill with a prominent black knob at the base, larger in males
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.
Mute Swan
The mute swan is one of the heaviest flying birds, with males weighing up to 14 kg. Despite its name, it is not truly mute, producing hissing, grunting, and snorting sounds. Mute swans form lifelong pair bonds and their aggressive defense of nesting territory is well known.