The great hornbill (Buceros bicornis) is a large Asian pied hornbill, belonging to the family Bucerotidae.
These hornbill species are distributed in India, Nepal, Bhutan, Myanmar, south China, Thailand, Cambodia, Laos, Vietnam, Malaysia and Indonesia. Vagrant populations of the great hornbill have been observed in Bangladesh. These hornbills are monotypic species.
Great hornbill - Overview
- Scientific name: Buceros bicornis
- Species author: Linnaeus, 1758
- Synonyms/Protonym: Buceros bicornis Linnaeus, 1758
- Family: Bucerotidae › Bucerotiformes › Aves › Chordata › Animalia
- Vernacular names: English: Great hornbill, Chinese: 双角犀鸟, French: Calao bicorne, German: Doppelhornvogel, Spanish: Cálao bicorne, Russian: Двурогий калао, Japanese: オオサイチョウ, Malay: Burung Enggang Papan
- Other names: great Indian hornbill, great pied hornbill
- Distribution: India, Nepal, Bhutan, Myanmar, south China, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia
- Diet and feeding habits: fruits, figs, berries, flowers, buds, small mammals, small birds, small reptiles, large insects
- IUCN status listing: Near Threatened (NT)
Appearance, physical description and identificationThe great hornbill (Buceros bicornis) is a large Asian hornbill, measuring 95 to 105 cm in length and weighing 2500 to 3400 grams. The female is slightly smaller and weighs 2100 to 3300 grams.
These great hornbill species have a distinctive broad black band, half way down the length of their long white tail. They also have prominent eyelashes. The bill is massive and curved downwards. The upper mandible is bright yellow, whereas the lower mandible is pale yellow. The base of the bill is black. The face and the chin are also black.
The hornbill casque is a hollow 'U' shaped growth on the upper mandible. The casque is bright yellow on the anterior end and black on the distal end. The crown, nape, neck and throat are pale yellow. The back, breast and belly regions are black. The vent region and undertail are whitish.
The hornbill wings are black with yellow primaries and white trailing edge. The females have bluish white irises while the males have reddish irises. The orbital skin is pinkish in females. Their call is a repeated resonant, growling “rroh” sound.
|Birds of India - Image of Great hornbill - Buceros bicornis by Kalyanvarma|
|Indian birds - Picture of Great hornbill - Buceros bicornis by Steve Wilson|
|Birds of India - Photo of Great hornbill - Buceros bicornis by N. A. Naseer|
Origin, geographical range and distributionThe great hornbill species are distributed in India, Nepal, Bhutan, Myanmar, south China, Thailand, Cambodia, Laos, Vietnam, Malaysia and Indonesia. Vagrant populations have been observed in Bangladesh. A small feral population thrives in Singapore.
In India, these great hornbill species are distributed in the states of Kerala, Tamilnadu, Karnataka, Goa, Maharashtra, Gujarat, Uttarakhand, Uttar Pradesh, Bihar, West Bengal, Assam, Nagaland, Meghalaya, Manipur and Tripura.
The Important Bird and Biodiversity Areas (IBA) of great hornbill in Nepal are, Parsa Wildlife Reserve, Mai Valley forests, Chitwan National Park, Bardia National Park and Barandabhar forests and wetlands. The IBA of these species in Vietnam are Yok Don and Kon Cha Rang.
Ecosystem and habitatThese great hornbill species have high forest dependency. These species occur in altitudes from 0 to 2000 meters.
These great hornbill species inhabit natural ecosystems like tropical and subtropical moist montane forests, tropical and subtropical moist lowland forests, wet evergreen forests, primary evergreen forests, mixed deciduous forests and dense old growth forests in hilly regions.
Diet and feeding behaviorThe diet of these great hornbill species is mostly fruits. Figs, wild fruits, berries, flowers, buds, small mammals, small birds, small reptiles and large insects are their primary food.
The great hornbills forage along branches, hopping and gleaning insects by tearing up the bark. They also catch rodents and lizrds on the branches. The prey is tossed in the air and swallowed. They have been observed to prey upon flying squirrel, Indian scops owl, jungle owlet and Sri Lanka green pigeon.
Reproduction and breeding habitsThe breeding season of the great hornbill is from January to April in its entire range. During the breeding season, they become highly vocal and make loud calls. These species are monogamous and highly territorial during the laying season. Fights among the males may involve aerial casque-butting.
The great hornbills nest on large, tall and old trees rising above the canopy. They nest in natural holes and cavities in the old trees. After selecting a nesting hole, the female seals up the opening with its feces and fruit pulp. A small vertical slit-opening is kept for receiving food from the male and for voiding feces.
The typical great hornbill clutch contains one or two eggs. The chicks hatch out after 38 days of incubation. After entering the nesting hole, the female undergoes a complete moult. The hatchlings lack down feathers.
The female great hornbill and the young ones are totally dependent on the male for feeding them. The death of the male during this period may lead to starvation and death of the whole family.
Migration and movement patternsThe great hornbill species are non-migrant resident birds.
Post breeding, the hornbill juveniles may disperse and establish in new locations within the range. They may make local movements for feeding and breeding within their range.
Conservation and survivalThe global population size of the great hornbill (Buceros bicornis) is estimated to be around 13000 to 27000 individual birds. The overall population trend of these hornbill species is considered to be decreasing. Throughout its range it is reported to be scarce to locally common. The generation length is 18.4 years. Their distribution size is about 10,300,000 sq.km.
The great hornbill (Buceros bicornis) is approaching the thresholds for being Vulnerable, under the range size criterion, under the population trend criterion and also under the population size criterion. Logging and forest clearance, hunting pressure due to casques collection as trophies and trapping for pet trade are the main threats that may endanger the survival of these hornbill species.
IUCN and CITES statusThe IUCN (International Union for Conservation of Nature) has categorized and evaluated the hornbill species and has listed it as "Near Threatened". CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) status is ‘Evaluated’ for the great hornbill (Buceros bicornis) and is listed in Appendix I.
1.Image source: https://commons.wikimedia.org/wiki/File:Great-Hornbill.jpg
Image author: Kalyanvarma | License: CC BY-SA 3.0
2.Image source: https://commons.wikimedia.org/wiki/File:Pleased_to_meet_you_(10400572063).jpg
Image author: Steve Wilson | License: CC BY 2.0 as on 3/21/17
3.Image source: https://commons.wikimedia.org/wiki/File:Great_Hornbill_(female)_by_N.A._Nazeer.jpg
Image author: N. A. Naseer / www.nilgirimarten.com / firstname.lastname@example.org | License: CC BY-SA 2.5 IN
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