The knobbed hornbill, also known as Sulawesi wrinkled hornbill, is a colourful hornbill native to Indonesia. The species is sometimes placed in the genus Aceros. The knobbed hornbill is the faunal symbol of South Sulawesi province.
Region
Southeast Asia (Wallacea)
Typical Environment
Occurs across Sulawesi and several adjacent islands, mainly in primary and mature secondary rainforest. It prefers tall, undisturbed lowland and hill forests with abundant large fruiting trees and suitable nesting cavities. Birds often range widely to track seasonal fruiting, using ridgelines and riverine corridors. They can visit forest edges and agroforests when trees are fruiting but rely on large tracts of intact forest for breeding.
Altitude Range
Sea level to 1500 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 2/5
This striking hornbill is endemic to Sulawesi and nearby islands in Indonesia and is the faunal symbol of South Sulawesi. Males have a prominent knobbed casque that enlarges with age. Like other hornbills, the female seals herself inside a tree cavity during nesting, relying on the male to feed her and the chick. It is a key seed disperser for large forest trees, especially figs.
Male
Temperament
social and active
Flight Pattern
strong flier with deep wingbeats and short glides
Social Behavior
Typically seen in pairs or small family groups; larger feeding flocks form at heavily fruiting trees. Monogamous pairs nest in large tree cavities; the female seals the entrance, leaving a narrow slit for the male to deliver food. After the chick grows, the female breaks out and both parents continue provisioning.
Migratory Pattern
Resident
Song Description
Vocalizations are loud honks, cackles, and barking notes that carry through the canopy. Wingbeats produce a distinctive whooshing sound during flight. Calls intensify at dawn and around communal fruiting trees.
Plumage
Glossy black body with a contrasting white tail bearing a black subterminal band; males show rich rufous-orange head and neck, females are mostly black. Both sexes have a large pale horn-colored bill with a high casque; the male’s casque has a distinctive swollen knob with reddish tones. Bare throat skin is vivid blue, especially prominent when calling.
Diet
Primarily frugivorous, with figs (Ficus) and other large-seeded fruits forming the bulk of the diet. It supplements with insects and occasionally small vertebrates or eggs, especially when feeding chicks. The species swallows fruit whole and later regurgitates seeds, dispersing them far from the parent tree.
Preferred Environment
Forages high in the canopy at fruiting trees, often moving along ridgelines and forest edges. Will visit secondary forests and agroforests when fruit is abundant but favors mature rainforest for consistent resources.
