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A rare knob-billed duck (Sarkidiornis melanotos) was recorded for the first time at the Pong Lake Wildlife Sanctuary in Himachal Pradesh on 14 June 2026.
Biological Profile and Taxon
- Scientific Classification: Known scientifically as Sarkidiornis melanotos, it belongs to the waterfowl family Anatidae.
- Dual Nomenclature: It is also widely referred to as the African comb duck.
- Taxonomic Splitting: Most major ornithological authorities separate the Old-World knob-billed duck from its closely related New World relative, the comb duck (Sarkidiornis sylvicola), found in South America.
Geographic Range and Habitat
- Global Footprint: It is distributed widely across tropical and subtropical wetlands in Sub-Saharan Africa, Madagascar, the Indian subcontinent, and mainland Indochina.
- Ecosystem Choice: The bird prefers static, slow-moving freshwater swamps, marshes, lakes, and seasonal flooded plains.
- Migration Nature: It is largely a resident species, though it disperses extensively during the wet monsoon season to follow regional water availability.
Physical Features
- Massive Proportions: It ranks as one of the largest species of duck in the world. Its length spans 56 to 76 cm, with a wide wingspan of 116 to 145 cm, and weights reaching up to 2.9 kg.
- The Distinctive "Comb": The male features a large, fleshy, leaf-shaped black knob (basal knob) on top of its bill, which expands in size during the breeding season. This acts as a sexually selected trait to attract females.
- Striking Colouration: Adults have a distinct white head and neck freckled with dark spots. Their upperparts feature dark, glossy blue-black feathers with prominent green and purple iridescence.
- Sexual Dimorphism: Males are significantly larger than females; females completely lack the prominent black facial knob and have duller, less metallic plumage.
Behaviour, Diet, and Nesting
- Dabbing and Grazing: The species is an omnivore, feeding on aquatic vegetation, seeds, small fish, and invertebrates. It occasionally feeds in agricultural fields, which can sometimes cause minor problems for rice farmers.
- Tree Perchers: Unlike most typical ducks, knob-billed ducks are unique "perching ducks" that frequently roost on elevated tree branches, cement walls, or power lines.
- Cavity Breeders: They build their nests primarily inside natural tree holes or cavities close to water bodies, and occasionally in tall grasses.
- Flock Sizing: They travel in small family units during the wet season, but congregate into large flocks of up to 100 birds during dry spells.
Conservation and Protection Status
- IUCN Red List: Categorized globally as Least Concern (LC) due to its vast geographical range.
- Local Decline: Despite the global status, wild populations are experiencing steady local declines due to wetland drainage, deforestation, and illegal hunting.
- International Treaties: It is protected under Appendix II of CITES and is a designated species under the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA).
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