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. The population is decreasing. Male and female black-casqued hornbill differ in physical appearance and are therefore an example of sexual dimorphism. The males are larger, have black feathers on their head, and have a larger casque. The females have brown hood of feathers. The black-casqued hornbill is known for its intelligence. They are most commonly found in pairs, but small groups of up to 5 are also somewhat frequent. They feed on insects and at least 19 species of fruit.