The wreathed hornbill (Rhyticeros undulatus) is an Old World tropical bird of the hornbill family Bucerotidae, also called bar-pouched wreathed hornbill due to its distinctive blue-black band on its lower throat sac. It is named after its characteristic long, curved bill that develops ridges, or wreaths, on the casque of the upper mandible in adults. Males are black with a rufous crown, a white upper breast and face, and a yellow featherless throat. Females are uniformly black with a blue throat and are slightly smaller than males.
The wreathed hornbill ranges across the foothills and evergreen forests of Northeast India and Bhutan to Bangladesh, Southeast Asia and the Greater Sunda Islands. It is a frugivore and feeds mainly on large fruits, which it swallows whole leaving the seeds intact. This feeding behaviour plays an important ecological role for the long-distance seed dispersal in forest ecosystems.
The wreathed hornbill is threatened by hunting, habitat fragmentation and deforestation. It has been listed as Vulnerable on the IUCN Red List since 2018, as the global population is estimated to decrease due to these threats.