|A pair at Walsrode Bird Park, Germany
(female in foreground)
The knobbed hornbill (Aceros cassidix) also known as Sulawesi wrinkled hornbill 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 reddish casque on the top of his bill. The female has a black face and neck, a yellow casque, and brownish eyes.
As with other hornbills, the knobbed hornbill is believed to be a monogamous species. The diet consists mainly of fruits and figs. 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.
The knobbed hornbill is the faunal symbol of South Sulawesi province.