African Black Duck vs Knob-billed Duck

Anas sparsa compared with Sarkidiornis melanotos

Side-by-Side Comparison

Attribute African Black Duck Knob-billed Duck
Scientific Name Anas sparsa Sarkidiornis melanotos
Order Anseriformes Anseriformes
Family Anatidae Anatidae
Conservation Status Least Concern Least Concern
Length
Wingspan 49.5 cm (19.5 in) 64.2 cm (25.3 in)
Weight 996.8333333333334 g (35.16 oz) 1817.5 g (64.11 oz)
Diet -- --
Clutch Size 4-9 6-20
Population Trend

Habitat Comparison

Shared Habitats

African Black Duck only

Knob-billed Duck only

African Black Duck

Fast-flowing rocky rivers and streams, mountain gorges, and waterfalls from sea level to 4,000 m across sub-Saharan Africa from Ethiopia and Kenya south to the Cape. Requires clear turbulent water with boulders.

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

African Black Duck

Song

Produces a harsh, resonant quacking call; alarm is a loud, emphatic quack repeated rapidly. Both sexes call with strong quacking; pairs duet with synchronized calls along African rivers.

Knob-billed Duck

Song

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.

Conservation Status

Least Concern

African Black Duck

Least Concern

Knob-billed Duck

How to Tell Them Apart

African Black Duck

Plumage

Dark blackish-brown plumage with bold white spots on back and scapulars. Iridescent blue-green speculum with white borders. Head dark with pale spots. Bill and legs dark gray. Sexes similar. Fast-flowing …

Knob-billed Duck

Plumage

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

African Black Duck

A medium-sized dark brown duck with white spots on the back, a dark bill, and orange legs. Found along fast-flowing rocky rivers and streams in Africa. Territorial and monogamous; pairs defend stretches of river. Related to Pacific Black Duck.

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.

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