| Knobbed Hornbill | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Bucerotiformes |
| Family: | Bucerotidae |
| Genus: | Rhyticeros |
| Species: | Rhyticeros cassidix |
The Knobbed Hornbill (Rhyticeros cassidix) is a hornbill from the genus Rhyticeros. It is the faunal symbol of South Sulawesi province in Indonesia.
Description[]
It is a large black hornbill with a yellow bill, red and black stripes on the sides of the bill, white tail feathers, pale blue skin around the eye, blackish feet, and bare dark blue throat. The male has a rufous/buff face and neck, black crown, orange-red eyes, and a high reddish casque on the top of his bill. The female has a mostly black plumage, a yellow casque, and brownish eyes. The length measures 70-80 cm and the mass is 2.36-2.5 kg.
The female undergoes a complete molt while inside the nest cavity. Males and non-breeding females go through a sequential molt.
Voice[]
The casque on top of the Knobbed Hornbill's head is believed to help the bird produce the loud barking sounds that they make.
Behavior[]
Diet[]
The Knobbed Hornbill forages within the forest canopy for its main food source, fruits. It eats insects, bird eggs and young chicks at times. Its tongue is too short to manipulate food, so it jerks its head back to get the food from the tip of its beak down to its gullet.
Reproduction[]
The Knobbed Hornbill is a monogamous species. Its breeding season spans 27-30 weeks, beginning from mid-June. That season is probably triggered by the end of rains, so that fruiting peaks when the chick(s) fledge(s). Nests are natural cavities located in large trees. The female seals herself inside a tree hole, using a mixture of feces, food and feathers to seal off the entrance except for a narrow slit, and lays 1-3 eggs. During her 32-35 days of incubation, the male will provide food for the female and will continue to do so after the chicks hatch. The female may leave the nest after the chicks fledge. From the three eggs laid, usually only one chick survives.
Distribution and Habitat[]
It is found in Indonesia in tropical evergreen lowland forests and forest edges, mainly from altitudes below 1,110 m and recorded up to 1,800 m above sea level, on the islands of Sulawesi, Buton, Lembeh, Togian and Muna. It is not migratory but will range over a large area looking for food.
Conservation[]
The considerably declining population due to habitat loss, hunting, gold mining and fires has the species evaluated as Vulnerable according to the IUCN red list.