Distribution: overlaps in eastern Nigeria, but extends to Cameroon, Equatorial Guinea, Gabon, Republic of the Congo, western Democratic Republic of the Congo and northern Angola. B B. f. duboisi overlaps in Cameroon but extends into Central African Republic, South Sudan, across most of the Congo River basin in the Democratic Republic of the Congo and into western Uganda.
Description: 45 cm. Male 463-710 g; female 412-500 g. It is the smallest among the Bycanistes hornbills with black head, neck and upperparts, white rump and underparts. Nominate race male B. f. fistulator has all-black wings and white tips to outer tail feathers. Bill and casque are dark with creamy base and heavy ridges; skin around eyes blue. Female is smaller with smaller, darker bill and casque.
Habits: This species is found in primary evergreen rainforest and surrounding closed secondary forest, mangrove forest and swamp forest, in the lowlands up to 600 m elevation. Generally sedentary, but extends into nearby plantations to feed. It feeds mainly on fruits at canopy level, some 30-50 m off the ground. 91% of food is fruits; identified from tree species of at least 12 families and 40 genera. It also eats flowers, buds and young leaves, as well as agricultural crops such as maize and oil-palm fruits. It lands near the target tree and moves in cautiously, staying up to 30 min in the same tree before moving on and often visiting the same tree the next day. It also takes some small animals and will fly out of the canopy to hawk for flying insects such as winged termites and ants; it can also descend to the ground to follow driver-ants in search of prey. Mainly moves in family groups within a territory. Certain times of the year it will range widely in small flocks of 12-20 individuals, flying more than 6 km in one day within its range in search of fruiting trees and flying high above the canopy. It may also roost communally; flocks of up to 37 birds have been reported.