The black-casqued hornbill (Ceratogymna atrata), or black-casqued wattled hornbill, is a species of hornbill in the family Bucerotidae. It is found fairly commonly across sub-Saharan Africa, being known from Sierra Leone and Liberia in Western Africa (as well as most of the West African nations along the Gulf of Guinea), south to Angola and east to the Democratic Republic of the Congo and western Uganda. They are currently considered of near threatened, and their population is declining.
The black-casqued hornbill is a large, mostly black bird with bare-skinned blue wattles and skin around their eyes. Adult birds are typically between 60 and 70 cm (24 and 28 in) long, and can be distinguished from the similar yellow-casqued hornbill by the white scales found in their plumage. They are readily identifiable as a member of the hornbill family by the eponymous casque structure that the birds develop on their beaks as they mature.
Like many bird species, black-casqued hornbills exhibit sexual dimorphism. The males are larger, with black heads, and a larger casque. The females have brown hood of feathers.
Both male and female birds have a powerful, "braying" call, which can be heard over 2 kilometers away. The generally louder males also make other calls, including a resonant squawk and a soft chuckling alarm call.
Black-casqued hornbills spend most of their time high in the trees of lowland, evergreen forests, although they also occur in nearby plantations and mature secondary growth. They typically live together in pairs or small family groups, although flocks of up to 40 individuals have also been sighted. Flocking black-casqued hornbills may wander for hundreds of kilometers in search of fruiting trees, returning to favored roosting spots at night.
