Black-and-White Casqued Hornbill: Uganda's Noisiest Forest Bird
The black-and-white casqued hornbill (Bycanistes subcylindricus) is Uganda's most common large forest hornbill and certainly its loudest. At 60 to 70 centimetres and 700 to 900 grams, it moves through Kibale and Budongo forest in noisy groups of 4 to 20 birds, advertising its presence 500 metres away with a raucous, wailing call that fills the forest canopy. The species is named for the prominent casque — a hollow protrusion on the upper mandible — which is white in this species with a black base, providing a useful identification point against the similarly-sized trumpeter hornbill (Bycanistes bucinator) which has an all-black casque. The body plumage is black and white: black mantle and wings with a white belly, white rump and white tail tips visible in the characteristic undulating flight between trees.
Where to See It in Uganda
Kibale Forest: The most reliable site. Groups of black-and-white casqued hornbills move through the Kibale forest canopy throughout the day and are encountered on virtually every Kanyanchu trail walk. Their calling is so loud and persistent that they are detected before they are seen, and their direction of movement can be tracked by ear as they move from one fig tree to the next.
Budongo Forest: Also abundant. The Budongo Royal Mile trail is particularly productive, as the large fig trees lining the trail draw hornbill groups repeatedly throughout the morning.
Bwindi — Buhoma sector: Present in the lower forest area but less abundant than at Kibale or Budongo due to Bwindi's higher altitude and denser montane forest structure.
Fig Tree Dependence and Frugivory
Black-and-white casqued hornbill is a frugivore almost entirely dependent on fig trees (Ficus species) for the bulk of its diet. At Kibale, it tracks fruiting fig events across the forest, moving as a flock to any fig tree in active fruiting regardless of distance. At any given fig tree currently fruiting in Kibale, 5 to 15 casqued hornbills will be present along with green pigeons, Ross's turaco and various frugivorous monkey species. The fig-dependent frugivore community at Kibale is one of the richest in East Africa.
Nesting and the Sealed Nest
Like all hornbills, the black-and-white casqued hornbill nests in tree cavities and the female is sealed inside the cavity during incubation and early chick-rearing. The male uses mud, bark fragments and faeces to seal the nest entrance to a narrow slit just wide enough to receive food from the male. The female remains sealed inside for 40 to 60 days. This sealed-cavity nesting system protects the female and eggs from snakes, genets and other tree-climbing nest predators.
The Hornbill and the Forest: Seed Dispersal Role
The black-and-white casqued hornbill's diet of forest figs and other large fruits makes it one of the most important seed dispersers in the Kibale Forest ecosystem. A fruit swallowed whole is carried for 0.5 to 3 kilometres before being regurgitated or defecated — the seed lands in a location far from the parent tree where germination competition is lower. At Kibale, where chimpanzees are the other primary large frugivore-seed disperser, the hornbills and chimpanzees share the same fruiting fig events, each contributing to the regeneration of the forest through their seed dispersal movements. Studies at Kibale have documented that the loss of large frugivores like hornbills leads to measurable changes in forest tree composition over decades — the hornbills are not ornamental; they are functional ecosystem participants.
Group Behaviour and Vocalisation
Black-and-white casqued hornbills are intensely social birds that almost never occur singly in Uganda's forests. Groups of 4 to 20 birds move through the canopy together, with continuous vocal communication between group members — the overlapping, wailing calls of multiple birds create a cacophony that has been described as sounding like a group of cats being startled simultaneously. The call carries through 500 metres of closed forest canopy, and at Kibale in the early morning when 3 to 4 groups may be moving simultaneously through adjacent territories, the hornbill vocal background can dominate the entire soundscape.
The casque itself is not merely ornamental — though its white-on-black colouration is species-specific in a way that allows casqued hornbills to distinguish each other from the similar trumpeter hornbill (Bycanistes bucinator). The casque houses resonating chambers that amplify the vocal calls, which is why the casqued hornbill's call is significantly louder per body weight than other hornbill species without casques.
Photography at Kibale: Canopy Fig Events
The most productive black-and-white casqued hornbill photography occurs at a fruiting fig tree where groups of 8 to 15 birds assemble. The birds feed for 5 to 10 minutes in the fig canopy, then depart in noisy flight for the next fruiting tree. At a large fig in the open section of Kanyanchu trail, the hornbills descend close enough for telephoto portraits without the canopy obstruction that plagues most forest hornbill photography. Camera settings: ISO 400 to 800, 1/800 second to freeze wing movement, f/6.3 for depth of field. A specialist guide who monitors fruiting fig trees can position clients at the right tree 20 to 30 minutes before a hornbill group arrives.
Frequently Asked Questions: Black-and-White Casqued Hornbill Uganda
How loud is the black-and-white casqued hornbill call?
Extremely loud — the wailing call of a group carries clearly 500 metres through closed forest. It is typically the first wildlife sound heard at Kibale park gate in the morning, often before 6:00am.
What is the difference between casqued and trumpeter hornbill?
White-based casque versus all-black casque is the primary field mark. Trumpeter hornbill also has a larger red facial wattle and a distinctive crying-baby call. Both occur at Kibale but casqued is significantly more common — roughly 10 to 1 in abundance.
Does black-and-white casqued hornbill also occur at Bwindi?
Yes — it is present in the lower Buhoma sector forest at Bwindi but at much lower density than at Kibale or Budongo. The altitude at Bwindi is too high for the dense lowland fig forest that the species prefers, so most Bwindi sightings are of single pairs rather than the large groups seen at Kibale.
Does the casqued hornbill eat anything other than figs?
Yes — while fig trees are the primary food source and the species tracks fruiting events across the forest, it also eats other large forest fruits (Maesopsis, Celtis, Chrysophyllum), palm nuts and occasionally large insects. During the nesting period, the male brings a diverse diet of small prey items to the sealed female — including lizards, large beetles and nestling birds — which are regurgitated from a gular pouch developed specifically for this food-delivery function.
What is the hornbill's role in the Kibale Forest ecosystem?
As primary seed dispersers for large-seeded fig species, black-and-white casqued hornbills are a keystone species for Kibale's tree diversity. Models of hornbill removal from Kibale-equivalent forest systems predict 15 to 25% reduction in large-seeded tree regeneration within 50 years. The hornbills are not merely charismatic; they are functional, critical participants in the forest ecosystem that has supported their population for millennia.
How can I tell the Bycanistes hornbills from a boat on the Kazinga Channel?
The black-and-white casqued hornbill occurs at Kibale and forest sites, not typically at the Kazinga Channel (which is savannah habitat). The grey hornbill and crowned hornbill are the more typical Queen Elizabeth park hornbill species seen from the Kazinga Channel boat trip. The casqued hornbill remains a western forest specialist.
Contact Shoebill Uganda Bird Tours — black-and-white casqued hornbill is a guaranteed species on any Kibale morning walk and one of the most photographed forest birds in Uganda.