Rhinoceros Hornbill Buceros rhinoceros Scientific name definitions

80–90 cm; male 2465–2960 g, female 2040–2330 g. Large mainly black hornbill with white thighs and vent, black band across white tail ; bill and casque cosmetically coloured orange and red with preen oil. Male nominate race with large casque black at base, more or less recurved at tip; black-rimmed red eyes. Female smaller, casque smaller and without black, red-rimmed white eyes. Juvenile with small, casqueless bill, blue-grey eyes. Race <em>borneoensis</em> smaller, with shorter and broader casque more sharply recurved at tip ; <em>silvestris</em> with broader black tail-band, anterior casque normally not rolled back.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Extensive areas of primary evergreen forest , extending into tall secondary forest; often crosses more open habitats; occurs at up to 1400 m.

Breeding pairs sedentary in many areas; in non-breeding period, may make long movements in search of fruiting trees, especially immatures in flocks of up to 25.

Mainly fruits , especially figs, but also various lipid-rich capsules and drupes; in addition, eats any small animals it can capture, mostly arthropods, but also lizards, tree-frogs and bird eggs. Usually forages in pairs; sometimes in small flocks when not breeding.

A series of short, explosive, resonant  “rroh” calls. Pairs also call antiphonally on two different pitches “rroh-rroh...”, both when perched and in flight. In flight also utters a bisyllabic “rroh-yaw”, the second syllable of which is more yelping.

Lays aseasonally, in Jan, Mar–Jun, Sept and Nov. Indication that sometimes breeds co-operatively, both in wild and in captivity. Nest in natural cavity 9–15 m up in tall forest tree, probably rarely in limestone cliff; entrance hole often an elongated slit. Clutch 1–2 eggs; incubation 37–46 days; male feeds nest occupants by regurgitating multiple food items from gullet; female moults remiges and rectrices after enclosure, emerges 39–51 days after chicks hatch; fledging 78–80 days.

VULNERABLE. CITES II. Previously considered Near Threatened. Occurs in several large mainly lowland reserves, including Taman Negara National Park (Malaysia), Gunung Leuser and Way Kambas National Parks and Berbak Game Reserve (Sumatra) and Danum Valley Conservation Area (Borneo), but always at low densities. Distribution and numbers reduced in many areas over wide range, mainly through cutting of forest for timber and agriculture. Hunted in many areas for the bill and tail feathers, which are used in ceremonial dress; also captured for trade and for food.