Mallard vs Knob-billed Duck
Anas platyrhynchos compared with Sarkidiornis melanotos
Side-by-Side Comparison
| Attribute | Mallard | Knob-billed Duck |
|---|---|---|
| Scientific Name | Anas platyrhynchos | Sarkidiornis melanotos |
| Order | Anseriformes | Anseriformes |
| Family | Anatidae | Anatidae |
| Conservation Status | Least Concern | Least Concern |
| Length | 58.0 cm (22.8 in) | — |
| Wingspan | 90.0 cm (35.4 in) | 64.2 cm (25.3 in) |
| Weight | 1100.0 g (38.80 oz) | 1817.5 g (64.11 oz) |
| Diet | Omnivorous — aquatic plants, seeds, insects, crustaceans, and mollusks. Feeds by dabbling, upending, and grazing … | -- |
| Clutch Size | 4-18 | 6-20 |
| Population Trend | — | — |
Size Comparison
Habitat Comparison
Mallard
Nearly any wetland habitat including lakes, rivers, ponds, marshes, estuaries, and urban park ponds.
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.
Song & Call Comparison
Mallard
Female gives the classic 'quack-quack-quack', descending in pitch. Male utters soft nasal 'raeb-raeb'. Both give a high 'gag-gag-gag' when alarmed or taking flight.
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.
Geographic Range & Migration
Mallard
Native across the Northern Hemisphere in North America, Europe, and Asia. Introduced to Australia and New Zealand.
Knob-billed Duck
Conservation Status
Mallard
Knob-billed Duck
How to Tell Them Apart
Mallard
Breeding males have an iridescent green head, white neck ring, chestnut breast, and grey body. Females are mottled brown. Both sexes show a blue speculum bordered by white.
Broad, flat bill — yellow-green in males, orange-brown in females
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 …
About These Birds
Mallard
The mallard is the ancestor of most domestic duck breeds and the most abundant and widespread dabbling duck in the world. Males perform elaborate courtship displays including head-bobbing and whistle-grunt calls. Mallards are highly adaptable, thriving in both wilderness and urban environments.
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.