Which rainforest bird has a large casque on top of its bill and is native to Southeast Asia?

The rhinoceros hornbill is the rainforest bird with a large casque on top of its bill and a range in Southeast Asia.

Buceros rhinoceros is a large hornbill found in the lowland forests of the Malay Peninsula, Sumatra, Java, and Borneo. Its most recognizable feature is the bright yellow-and-red casque, a hollow structure rising above the bill. The casque is not a horn in the mammalian sense; it is made largely of keratin and helps create the bird’s distinctive profile.

Rhinoceros hornbills eat fruit, especially figs, as well as insects, small reptiles, and other animal prey. By carrying fruit between trees, they can help disperse rainforest seeds.

Like many hornbills, the species has an unusual nesting arrangement. The female seals herself inside a tree cavity with mud and plant material, leaving only a narrow opening through which the male passes food until the young are ready to emerge.