The knobbed hornbill (''Rhyticeros cassidix''), also known as Sulawesi wrinkled hornbill, is a colourful

hornbill Hornbills (Bucerotidae) are a family (biology), family of bird found in tropical and subtropical Africa, Asia and Melanesia. They are characterized by a long, down-curved bill which is frequently brightly coloured and sometimes has a Casque (an ...

native to Indonesia. The species is sometimes placed in the genus '' Aceros''. The knobbed hornbill is the faunal symbol of

South Sulawesi South Sulawesi ( id, Sulawesi Selatan) is a province in the southern peninsula of Sulawesi. The Selayar Islands archipelago to the south of Sulawesi is also part of the province. The capital is Makassar. The province is bordered by Central Sula ...

province.

Description

This is a large black

with a yellow

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Plac ...

, 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.

Distribution and habitat

An Indonesian endemic, the knobbed hornbill is found in

Sulawesi Sulawesi (), also known as Celebes (), is an island in Indonesia. One of the four Greater Sunda Islands, and the world's eleventh-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Mindanao and the Sulu Ar ...

, Buton, Lembeh,

Togian The Togian (or Togean) Islands are an archipelago of 56 islands and many offshore islets, situated in the Gulf of Tomini, off the coast of Central Sulawesi, in Indonesia. The largest islands are Batudaka, Togean, Talatako and Una-Una. Ther ...

and

Muna Island Muna (Pulau Muna) is an island in the Southeast Sulawesi province of Indonesia with an area of and had a population of 316,293 at the 2010 Census and 368,654 at the 2020 Census.Badan Pusat Statistik, Jakarta, 2021. It is just southeast of the i ...

. 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. Aceros cassidix -North Sulawesi-4

Ecology

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. 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 The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

. 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.

Gallery

File:Aceros cassidix -Weltvogelpark Walsrode, Germany-8a.jpg, Male at Walsrode Bird Park File:Naturalis Biodiversity Center - MMNAT01 AF NNM001000152 - Natuurkundige Commissie voor Nederlandsch-Indië - Bird species - Art.jpg, Early drawing by the Dutch colonial Natuurkundige Commissie voor Nederlands-Indië, 1820s. File:Aceros cassidix 2 (Frank Wouters).jpg, File:Aceros cassidix -Vogelpark Walsrode -pair-8a.jpg, Pair at Walsrode Bird Park, Germany File:Cranorrhinus_cassidix_190.jpg, Skeleton

References

{{Taxonbar, from=Q27074824

knobbed hornbill The knobbed hornbill (''Rhyticeros cassidix''), 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 Su ...

Endemic birds of Sulawesi