Wrinkled hornbill

This species is especially sensitive to forest loss due to its reliance on large trees for nesting, but we can help by shopping for sustainably harvested palm oil, wood, and paper products.

Physical features

The species is sexually dimorphic. Males are slightly larger, with different coloration than females.

Wrinkled hornbills are mostly black with white tails. Males are white on the sides of the head, neck, and upper breast (although it appears pale yellow or reddish due to staining from preen oil).

Both sexes have an inflatable throat pouch. In females, it is blue in color. In males, it is white or pale yellow.

Both sexes have bare blue skin around the eyes. Males have red eyes, while females’ eyes are more grey-brown.

Beaks differ slightly between males and females. Both sexes have long, curved beaks with a casque. Females’ beaks are all yellow and mostly smooth. Males have a red, wrinkled casque that is slightly larger than the females’, and the base of their mandibles (lower beaks) are also reddish and wrinkled.

Males can weigh up to three and a half pounds and can reach a little over two feet in length (70 centimeters).

Range and Habitat

Range – Parts of Brunei Darussalam, Indonesia, Malaysia, Thailand (possibly extinct), and formerly Singapore; recently recorded in Cambodia

Habitat – Primary evergreen and swamp forests of the Sundaic lowlands; the species is intolerant of degraded or secondary habitat, but it can persist in selectively logged forest adjacent to primary forest

Diet: Omnivore

Wild – mostly drupes (stone fruits) and fruit with numerous small seeds, such as figs, and small animals such as frogs, lizards, snails, arthropods, and young birds; forages in pairs or sometimes in small flocks

They generally do not drink water because they get it from their food.

Zoo – commercially prepared hornbill pellets, a variety of fruits, insects

Reproduction

Little is known about this species’ reproductive behavior in the wild.

Breeding usually occurs in the rainy season (December - January) and fledging is usually complete by May.

They create nests in natural cavities in large trees. Like other hornbills, the female will seal herself within the nest, usually with droppings and food remains. The male will feed her by regurgitation.

In human care, they usually lay two to three eggs (rarely, four) and incubate them for about 29 days. If eggs are lost, they can lay more.

Chicks hatch with pink skin that turns dark purple-black after about 10 days.

Immature birds of both sexes have plumage like adult males. Immature females molt into adult face and neck colors around one year of age.

The female leaves the nest when the chicks fledge, around 65-73 days after hatching.

The complete nesting cycle takes about four months.

Conservation: Endangered

Although wrinkled hornbill population sizes have not been quantified, the species has been described as always uncommon and is very rare in some areas.

Their biggest threat is rapid forest loss throughout their range, caused by illegal logging and land conversion. The species is reliant on lowland forest, which is particularly threatened by land conversion for oil palm and rubber plantations as well as small-scale agriculture.

The species is particularly sensitive to forest loss, as these birds require large trees to nest and show a strong avoidance of degraded or secondary forest.

References

BirdLife International. (2018). Rhabdotorrhinus corrugatus. Retrieved May 16, 2022 from the IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/22682514/132244524

Brevard Zoo. (n.d.). Wrinkled hornbill (Aceros corrugatus). Retrieved May 31, 2022 from https://brevardzoo.org/animals/lands-of-change/wrinkled-hornbill/

Coraciiformes Taxon Advisory Group. (n.d.). Wrinkled hornbill (Aceros corrugatus). Retrieved May 16, 2022 from https://www.coraciiformestag.com/Hornbill/corrugatus/corrugatus.html

Kemp, A., Boesman, P., & Sharpe, C. (2020). Wrinkled Hornbill (Rhabdotorrhinus corrugatus). Retrieved from Birds of the World: https://birdsoftheworld.org/bow/species/wrihor1/cur/introduction

Zoo Atlanta animal care team