Knob-billed Duck vs Blue-billed Teal
Sarkidiornis melanotos compared with Spatula hottentota
Side-by-Side Comparison
| Attribute | Knob-billed Duck | Blue-billed Teal |
|---|---|---|
| Scientific Name | Sarkidiornis melanotos | Spatula hottentota |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 64.2 cm (25.3 in) | 29.4 cm (11.6 in) |
| Weight | 1817.5 g (64.11 oz) | 269.2 g (9.50 oz) |
| Diet | Dabbles for seeds and aquatic invertebrates; diet shifts toward invertebrate prey in spring breeding season; … | Feeds on seeds, aquatic plants, and invertebrates; filter-feeds in shallow water; broadly omnivorous and seasonally … |
| Clutch Size | 6-20 | 5-12 |
| Population Trend | — | — |
Habitat Comparison
Knob-billed Duck
Freshwater lakes, marshes, floodplains, and forested wetlands across sub-Saharan Africa and South and Southeast Asia from India to southern China. Nests in large tree hollows near water.
Blue-billed Teal
Freshwater lakes, marshes, pans, and flooded grasslands across sub-Saharan Africa from Senegal and Sudan south to the Cape. Nomadic; follows seasonal rains. Common but easily overlooked among reed beds.
Song & Call Comparison
Knob-billed Duck
A low, grunting 'wuk' or soft, nasal 'krank'. Similar to Comb Duck in call quality. Generally quiet; calls are not loud or distinctive compared to other large African waterfowl.
Blue-billed Teal
Male utters a soft, teal-like peep; female gives a muted quack. Pairs call quietly in dense papyrus; soft contact calls help birds maintain proximity in thick African marsh vegetation.
Geographic Range & Migration
Knob-billed Duck
Breeds on sub-Arctic tundra; winters on the Atlantic coast of North America from Labrador to Florida and the Gulf Coast.
Blue-billed Teal
Breeds in Arctic and subarctic Eurasia; winters at sea in the North Atlantic and from western Europe to eastern Africa.
Conservation Status
Knob-billed Duck
Blue-billed Teal
How to Tell Them Apart
Knob-billed Duck
Males have white head with black spots; iridescent dark blue-black back and wings; white underparts with gray flanks. Large black fleshy knob atop bill. Females smaller, brown, and lack the …
Blue-billed Teal
Small; males have pale blue-gray bill contrasting with brown-gray body. Head finely spotted; underparts barred brown and white. Males show powder-blue forewing in flight. Females browner. African marsh species.
About These Birds
Knob-billed Duck
Old World equivalent of the Comb Duck, with iridescent black-and-white body and the male's distinctive bill knob. Found across sub-Saharan Africa and South Asia. Uses tree cavities for nesting. Gregarious outside breeding season; forms large flocks at seasonal wetlands.
Blue-billed Teal
A small dark teal with blue-grey bill and legs, brown-streaked plumage, and fine pale spotting on the flanks. The most widespread teal in sub-Saharan Africa. Found on freshwater lakes and marshes. Highly nomadic; follows seasonal rainfall. Swims low in the water like a pochard.