The Great Hornbill (Buceros bicornis)

also known as the Great Indian Hornbill or Great Pied Hornbill, is one of the larger members of the hornbill family. It is found in South and Southeast Asia. Its impressive size and color have made it an iconic species

Great hornbill ,male 121-150 cm,female 112-125 cm. Male 2610-3900 g; female 2157-3350 g. Very large hornbill with black band across white plumage areas on head, neck, wing coverts and base of tail usually cosmetically stained yellow with preen oil.

Male has black-rimmed red eyes and flat casque, forked at front with black edges. Female has white eyes with red rim that flushes brighter while breeding and smaller casque without black-lines.

Juvenile has blue-grey eyes, the small casqueless bill grows to maturity over five years. The voice is a loud and reverberating “kok”,often as pair duet, that can be heard over 800 meters in the forest, along with other guttural sounds.

great hornbill

Ecology and habits

Found in primary evergreen and moist deciduous forests. Occurs at sea level, but prefers hills further inland between 600 and 1,000 m elevation, in the Himalayan foothills and northern Thailand recorded to 2,000 m.Feeds in the canopy of large trees, often a resident pair or a family group together. Although largely sedentary, it ranges somewhat for food outside of breeding season. Flocks might congregate in fruiting trees or at communal evening roosts – up to 200 have been reported together on one occasion before 1927.

Occasionally descends to the grounds to pick up fallen fruits. Roams widely in search of fruiting trees, sometimes crossing high over open areas. It flies with heavy wing-beats, 3-4 flaps and a long glide; the massive wings produce a loud whooshing sound.

In Khao Yai NP food eaten and delivered to the nest is mainly fruit, especially many different kinds of figs but also lipid-rich fruits such as those of the Meliaceae ( Aglaia , Dysoxylum , Chisocheton spp) However, Polyalathia viridis (Annonaceae) and Cinnamomum subavenum (Lauraceae) and Horsfieldia glaba (Myristicaceae) appear to be high among non-fig fruit items.

Flowers and buds are also taken, as well as many animals such as small mammals, birds and reptiles,as well as large insects and other arthropods. When hunting, this hornbill hops along the branches and pokes into crevices and bark for prey,grabbing it with its huge bill and tossing it in the air for a better grip, before flying off to deliver it to the nest.

A survey in Khao Yai NP in Thailand found that the diet by weight during breeding was 57% figs, 29% other fruits and 14% animal food with 30.5 g per observation-hour; a later survey in southern Thailand found a 54:41:5 ratio with 47 g per observation-hour brought to the nest.

Generally, in the non-breeding season there are fewer lipid-rich fruits available, and it relies even more on figs.

great hornbill

Breeding ecology

The nesting season runs form January to June throughout is range, and the species is territorial and monogamous. During breeding, the birds becomes very vocal. communicating with loud slow calls kok..kok..kok more rarely, aerial casque-butting has been recorded.

The nest is in a very large, live hardwood tree, and predominant trees used are Dipterocarpus gracilis and Cleistocalyx nervosum (Myrtaceae) in moist evergreen forest of Khao Yai NP shorea faguetiana , Hopea odorata , Neobalanocarpus heimii (Dipterocarpaceae) and Syzygium (Myrtaceae) in tropical rainforest in southern Thailand and Tetrameles nudiflora (Datiscaceae) in mixed deciduous forest and Dipterocarpus turbinata and Cleistocalyx nervosum in hill evergreen forest of Huai Kha Khaeng WS.

A hole in a limestone cliff has also been used. The cavity is a natural hole in those trees at 6-45 m above the ground depending on forest type. The female enters and seals herself inside, using mainly faeces for plaster material, also some chewed pieces of wood, bark and food debris, but little if any soil. An elongated 20 x 5-cm vertical slit is left open. 1-4, usually 2, eggs are laid at 4-5 days intervals; incubation is 38-40 days.

The male brings food at 30 g per hour for the female and her chicks. Usually, 3-5 visits are made per day, starting late morning,with each visit lasting 15-20 minutes; visits with animal food are shorter.Up to 185 items are delivered daily; the male has been know to deliver up to 50 grape-size fruits in one feeding, regurgitating them individually from his gullet.After the chicks hatch, the number of items delivered increases up to five-fold, but not the number of visits.



The male forages over a 1.3-4.5 km forested area around the nest,flying up to 3 km away.The female emerges when the chick is 14-59 days old or 85 days on average (range 62-121 days) after sealing in; after that she helps the male with the feeding.The chick then re-seals the nest entrance and fledges after 72-96 days. Total nesting cycle is between 102-144 days; in  captivity it is shorter. Radio tracked breeding male in breeding season in Khao Yai NP, daily movement was 4-14 km which covers 0.7-6 km; throughout the entire breeding season a covers about 7 km on average.

A survey from Khao Yai NP, Huai Kha Khaeng WS and southern Thailand found a nesting cycle of 120,123 and 111 days +- 7-10 days respectively. After fledging,the chick remains near the nest, a radio-tracked chick remaining within 2 km for several months.

The chick is depending on the parents for food until it is up to 6 months old and the casque begins to form. The tight bond between the pair, and the long and complex breeding cycle of this species, makes it difficult to breed in captivity,although there have been a few successes.

Longevity in captivity recorded to over 41 years and in the wild up to 30 years.