The great hornbill was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae.

[5] The species was formerly broken into subspecies cavatus, from the Western Ghats, and homrai, the nominate form from the sub-Himalayan forests.

[6] Variation across populations is mainly in size, Himalayan birds being larger than those from further south, and the species is now usually considered monotypic.

[citation needed] The most prominent feature of the hornbill is the bright yellow and black casque on top of its massive bill.

[citation needed] The casque is hollow and serves no known purpose, although it is thought to be the result of sexual selection.

[citation needed] The wing beats are heavy, and the sound produced by birds in flight can be heard from a distance.

This anatomical feature was noted by Richard Owen, who dissected a specimen that died at the Zoological Society of London in 1833.

[16] The great hornbill is native to the forests of India, Bhutan, Nepal, mainland Southeast Asia and Sumatra.

[23] Great hornbills are usually seen in small parties, with larger groups sometimes aggregating at fruit trees.

Great hornbills also forage on lipid-rich fruits of the families Lauraceae and Myristicaceae such as Persea, Alseodaphne and Myristica.

[29] They forage along branches, moving along by hopping, looking for insects, nestling birds and small lizards, tearing up bark and examining them.

A rare squirrel, the Travancore flying squirrel (Petinomys fuscocapillus) has been eaten, and Indian scops owl (Otus bakkamoena), jungle owlet (Glaucidium radiatum) and Sri Lanka green pigeon (Treron pompadora) have been taken as prey in the Western Ghats.

[33] The female hornbill builds a nest in the hollow of a large tree trunk, sealing the opening with a plaster made up mainly of feces.

[36] Roost sites are used regularly and birds arrive punctually at sunset from long distances, following the same routes each day.

[38] [39] The Sema Nagas consider the flesh unfit for eating, believing that it produces sores on their feet, as in the bird.

When dancing with the feathers of the hornbill, they avoid eating vegetables, as doing so is also believed to produce the same sores on the feet.

[1] Conservation programmes have attempted to provide tribes with feathers from captive hornbills and ceramic casques to substitute for natural ones.

Their extreme selectivity for mates and their long and strong pair bonds make them difficult to maintain for breeding.

[46] The great hornbill is called homrai in Nepal and banrao in Mussoorie, both meaning "King of the Jungle".

Norman Kinnear described William as follows in the obituary of Walter Samuel Millard:[49] Every visitor to the Society's room in Apollo Street will remember the Great Indian Hornbill, better known as the "office canary" which lived in a cage behind Millard's chair in Phipson & Co.'s office for 26 years and died in 1920.