Helmeted hornbill (Rhinoplax vigil)

Synonyms: Buceros vigil
Spanish: Cálao de Casco
GenusRhinoplax (1)
SizeTotal length: 110 - 120 cm (2)
Tail feather length: up to 50 cm (3)
Male weight: 3.1 kg (2)
Female weight: 2.6 - 2.8 kg (2)

The helmeted hornbill is classified as Near Threatened (NT) on the IUCN Red List (1) and listed on Appendix I of CITES (4).

The largest hornbill in Asia (5), the helmeted hornbill (Rhinoplax vigil) is named for its bizarre ‘casque’, a protuberance which perches, helmet-like, on the upper half of the red and yellow, chisel-like bill (2). Unlike the casques of other hornbill species, which are typically hollow and extremely light, the casque of the helmeted hornbill is a solid block of an ivory-like substance (5).

The helmeted hornbill has dark brown upperparts and white underparts (2). Its extremely long central tail feathers, which often double the length of the entire bird, are white with dark banding patterns (3), and there are chestnut-brown feathers around the eyes (5).

Both male and female helmeted hornbills have a bare, featherless patch on the neck. This leathery skin is red in males and turquoise in the smaller females (2).

The peculiar call of the helmeted hornbill is described as a series of hollow ‘took ’notes followed by maniacal laughter, which is unique to this species (3).

The helmeted hornbill occurs in Southeast Asia, from Myanmar and Thailand, south through Malaysia to the islands of Sumatra and Borneo (2).

The helmeted hornbill also used to occur in Singapore, but is now believed to be extinct there (6).

The helmeted hornbill inhabits primary evergreen forest (2). It prefers forests within rugged terrain, up to elevations of 1,500 metres (7).

The helmeted hornbill is thought to be a territorial bird. Small groups of up to 14 non-breeding and immature birds may forage for food within a single area, but adult breeding pairs have their own territories (2).

The helmeted hornbill performs incredible displays in flight, in which individuals collide in mid-air, their casques clashing with a loud ‘clack’. This aerial jousting, which usually takes place between two males, often results in one or both hornbills being flung backwards, before righting themselves again in flight. These collisions are typically observed near fruiting fig trees, suggesting that the birds are fighting over access to their favoured food (5).

The main food of the helmeted hornbill is fruit, with figs being a particular favourite. However, this species also feeds on small animals, including mammals, snakes, and even smaller hornbills. It typically forages high up in the forest canopy, where it can sometimes be seen hanging upside-down, digging under the bark with its heavy beak and casque. Although breeding pairs share a territory, the male and female forage independently (2).

All hornbills are noted for their bizarre nesting habits, in which the female is sealed within a hollow tree to incubate the eggs (2). A nest is created within a natural hollow, high in a tree, and the female is then sealed within the hollow with mud by the male (2) (3). Only a small hole is left, through which the male passes the female regurgitated food, while the female incubates the eggs (2). The helmeted hornbill has been observed to lay eggs in January to March, as well as in May and November (2). When the young have hatched, the female breaks out of the hollow, then reseals the entrance until the young have fledged (3).

There are a number of factors threatening the helmeted hornbill, and its population is known to be decreasing. Extremely rapid deforestation in Southeast Asia, due to logging and land conversion to agriculture, is particularly concerning, as even protected areas have been illegally targeted by loggers. Deforestation is believed to be the reason for the helmeted hornbill’s extinction in Singapore in the 1950s (2). Thankfully, its preference for remote hill forests limits the loss of its habitat somewhat, as these areas usually face less pressure from logging and agriculture (2) (7).

Forest fires have also destroyed and degraded the helmeted hornbill’s habitat, especially during the late 1990s (7).

The helmeted hornbill is also hunted for its casque. Due to its shape and size, the casque is a desirable substitute for ivory, being ideal for use in the carving of ornaments (8). The amazingly long tail feathers of the helmeted hornbill are also prized as exotic souvenirs (2).

The helmeted hornbill is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES), which means that international trade in the helmeted hornbill (or any part of it, such as its casque or tail) is prohibited (4).

A number of conservation measures have been proposed for the helmeted hornbill, including monitoring its populations and assessing the impact of hunting on this species. Protection of the remaining tracts of lowland forest throughout the helmeted hornbill’s range will also be vital for this bird’s survival (7).

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  1. IUCN Red List (March, 2010)
  2. del Hoyo, J., Elliot, A. and Sargatal J. (2001) Handbook of the Birds of the World. Volume 6: Mousebirds to Hornbills. Lynx Edicions, Barcelona.
  3. Forest Department Sarawak - Helmeted Hornbill (March, 2010)
  4. CITES (March, 2010)
  5. Kinnaird, M. and O’Brien, T.G. (2007) The Ecology and Conservation of Asian Hornbills: Farmers of the Forest. The University of Chicago Press, Chicago.
  6. Wee, Y.C., Tsang, K.C., Chan, M., Chan, Y.M. and Ng, A. (2008) Oriental pied hornbill: two recent failed nesting attempts on mainland Singapore. BirdingASIA, 9: 72-77.
  7. BirdLife International (March, 2010)
  8. Espinoza, E.O. and Mann, M.J. (1999) Identification Guide for Ivory and Ivory Substitutes. WWF, Baltimore. Available at: