The great hornbill is listed as Vulnerable in the IUCN Red List and Appendix I of CITES. It is also protected under Regulation of Minister of Environment and Forestry No. 20 of 2018, Law No. 5 of 1990 and Government Regulation No. 7 of 1999.
A great hornbill measures 95-105 cm in length and weighs 2.1-3.4 kg. Its casque is dark yellow, flattened but broadens and curves upward with a branched tip. The species has a heavy beak with dark yellow upper mandible, with a lower mandible that is white at the base and yellow at the tip.
The great hornbill’s plumage is predominantly black on the face, back, lower breast and wings. Its crown, neck, upper breast, abdomen, thigh and tail are white. Breast white with yellow tinge. Tail with black traverse bands and yellowish white lines on wings.
Adult male and female great hornbills can be distinguished by the physical characteristics. Male great hornbill has black circumorbital skin and red iris, while female has smaller, red circumorbital skin, whitish iris, and lacks the black coloration on its beak.
Figs, nutmegs and stone fruits are the primary foods for the great hornbill. During breeding seasons, the species will eat eggs, insects, worms, snails and crabs, as well as small amphibians, reptiles, mammals and birds. This hornbill species can tear or cut tree barks. Larger preys are killed by slamming on branches, which the bird later softens with their beak before ingesting the prey.
The great hornbill is usually solitary in certain territory. The species nests in natural vertical tree cavities located 8-35 m above the ground. The cavity opening is then sealed using their own feces, softened wood chips and tree barks, food remains and some soil if available. The female seals the opening from the inside while the male does the same from the outside. A pair of great hornbills require 3 days to seal the cavity opening, with 2 additional days by the female.
Breeding season take place on January-April with a nesting period of 113-140 days: 1-4 days to prepare and lay eggs, 38-40 days for incubation, and 72-96 days for the chicks to develop.
Females can lay 2 eggs, but only 1 egg survives into adulthood. When breeding, the male visits the nest to feed its mate fruits for 15-20 minutes every 2-3 hours, with a total frequency of 3-5 visits.
Great hornbill abundance is closely linked to the density of large trees that the species use for nesting. Sadly, habitat loss due to logging, land clearing and lowland forest degradation is a looming threat for the great hornbill. In addition, the species is targeted by poachers. Their meat is consumed and made into traditional medicine, and the bird is kept as pets.
Great hornbills can get loud in the early breeding season and when flying to their nests. They produce loud calls which can be heard from 800 m away. When flying, the hornbill flaps its wings 3-4 times quickly, heavily and loudly, followed by a long whistle and then soar with the end of the wings lifted and tail feathers spread open like a fan.
There have been reports of hybridization between the great hornbill and the rhinoceros hornbill both in the wild as well as captivity.
