Rhabdotorrhinus corrugatus
Red List Status: EN – Endangered, criteria A3cd+4cd (IUCN 2018)
Distribution: South Thailand, Peninsular and Bornean Malaysia, and Kalimantan (Borneo) and Sumatra (including islands of Rupat and Payong) and Batu Island, Indonesia.
Description: 65-75 cm. Male 1590 g. Male has black crown and nape, white face and throat but stained with yellow from preen oil, unbarred pouch white (not yellow), bill white but stained yellow with red at the base of upper mandible and brown wrinkle on lower mandible, and high red wrinkled (not wreath, creamy) casque. Both sexes have blue orbital skin (not red). The female is smaller, black with blue unbarred pouch; from the female Wreathed Hornbill by yellow (not creamy) bill and plain casque (no ridges). Juveniles of both sexes resemble adult male in plumage but are small, casqueless and pale yellow.
Voice: Makes 1-3 coughing notes repeated at intervals, sok sok sok or kowwow, a softer version in flight. Also utters very harsh pukekkek.
Habits: The Wrinkled hornbill is found in lowland rainforest, especially coastal swamp forest; usually below 30 m elevation but recorded up to 400 m a.s.l. Extends into selectively logged forest, but not secondary forest. It is not conspicuous and is usually seen more than heard. Feeds in the canopy of large emergent trees, mainly on fruits such as drupes; it is less attracted to figs than some other hornbills. It also takes some animal items when available. Breeding diet 67% fruit, with Oncosperma horridum (Arecaceae), Litsea and Cinnamomum (Lauraceae), Aglaia (Meliaceae), Gymnacranthera (Myristicaceae) and Syzygium (Myrtaceae) and figs predominant, and 33% animals, mainly insects and land snails but also feeds on reptiles, frogs and bird’s eggs. It searches through the foliage for food or occasionally picks off fruits in flight. Usually lives in pairs but sometimes in small flocks of up to 30 individuals. It moves extensively in search of fruiting trees on loud whooshing wing-beats, flying up to 10 km, high above the forest. It also attends communal roosts; has been known to cross the open sea.
