Knobbed Hornbill
Rhyticeros cassidix
A huge black hornbill with a prominent knob on the bill, conspicuous red “gills” on the sides of the beak, a turquoise-blue throat pouch, and a white tail. Males have a red casque and rufous neck, females a yellow knob and black neck. Juveniles resemble male, but with an entirely yellow casqueless bill. Found in pairs or groups in canopy of forested and wooded areas of lowlands and hills. Larger and more colorful than Sulawesi Hornbill. Gives powerful, short “krok” notes and a more drawn-out “oooo-aa-ooo-aaa.”
Identification
This is a large black hornbill with a yellow bill, white tail feathers, pale blue skin around eye, blackish feet and bare dark blue throat. The male has rufous/buff face and neck, orange-red eyes, and a high red casque on the top of his bill. The female has a black face and neck, a yellow casque, and brownish eyes.
Taxonomy
- Scientific name
- Rhyticeros cassidix
- Authority
- (Temminck, 1823)
- Order
- Bucerotiformes
- Family
- Bucerotidae
- Genus
- Rhyticeros
Range and habitat
An Indonesian endemic, the knobbed hornbill is found in Sulawesi, Buton, Lembeh, Togian and Muna Island. It inhabits evergreen forest at an elevation of up to 1,800 m and also makes use of secondary forest, woodland and plantations for foraging.
- Migration
- Resident species
Behavior
As with other hornbills, the knobbed hornbill is believed to be monogamous. Its diet consists mainly of fruits, but it will also take insects and small vertebrates. Breeding season spans 27–30 weeks and appears to be triggered by a dramatic reduction in rainfall. The female seals itself inside a tree hole for egg-laying using its own feces. During this time, the male will provide foods for the female and the young through a slit in the seal.<p>Knobbed hornbills are important seed dispersers in their habitat and influence the initial fate of seeds of several tropical forest tree species.
Conservation
The species is currently classified as vulnerable by the IUCN. Despite being locally very common, they are threatened by habitat destruction from logging (since they depend on large and mature trees for breeding) and to some extent by hunting.
- Population trend
- declining
Photos
Distribution
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