The Knobbed Hornbill, Aceros cassidix, also known as Sulawesi Wrinkled Hornbill is a large black hornbill

Hornbill

Hornbills are a 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-colored and sometimes has a casque on the upper mandible. Both the common English and the scientific name of the family...

 with a yellow bill

Beak

The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...

, 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 reddish casque on top of bill. The female has black face and neck, yellow casque and brownish eyes.

An Indonesia

Indonesia

Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

n endemic

Endemism in birds

An endemic bird area is a region of the world that contains two or more restricted-range species, while a "secondary area" contains one or more restricted-range species. Both terms were devised by Birdlife International....

, the Knobbed Hornbill is distributed in the tropical evergreen forests of Sulawesi

Sulawesi

Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...

, Buton

Buton

Buton , is an island in Indonesia located off the southeast peninsula of Sulawesi.-History:In the precolonial era, the island, then usually known as Butung, was within the sphere of influence of Ternate...

, Lembeh, Togian

Togian Islands

The Togian Islands are an archipelago of 56 islands and islets, in the Gulf of Tomini, off the coast of Central Sulawesi, in Indonesia. The three largest islands are Batudaka, Togian, and Talatakoh...

 and Muna Island

Muna Island

Muna is an island in the South East Sulawesi province of Indonesia with an area of . It is located just southeast of the island of Sulawesi....

.
As with other hornbills, the Knobbed Hornbill is believed to be a monogamous species. The diet consists mainly of fruits and figs. The female sealed itself inside a tree hole for egg-laying. During this time, the male will provide foods for the female and the young.

The Knobbed Hornbill is the faunal symbol of South Sulawesi

South Sulawesi

South Sulawesi is a province of Indonesia, located on the western southern peninsula of Sulawesi Island. The province is bordered by Central Sulawesi province to the north, South East Sulawesi province to the east and West Sulawesi province to the west...

 province.

Widespread and common throughout its native range, the Knobbed Hornbill is evaluated as Least Concern on the IUCN Red List

IUCN Red List

The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...

of Threatened Species.