The Great Hornbill (Buceros bicornis) is also known as the concave-casqued hornbill or great pied hornbill. It can be found in south-west India, south China and Indochina south to Peninsular Malaysia and Sumatra (Indonesia). The Great Hornbill is not found in Borneo. The life expectancy for Great Hornbill living in captivity are in the range of 50 years. In the wild, their lifespan can reach a range of 35-40 years (Paruchuri, 2011).
The total length from head to tail of a Great Hornbill is between 95 and 120 cm, and its wingspan is between 151 and 178 cm. They are typically 3 kg in weight (Paruchuri, 2011). They are easily recognized by their vivid colours. The body, head, and wings are primarily black, while the abdomen and neck are white. The tail is white and a subterminal black band crossed by the white tail. A preen gland located close to the tail releases coloured oil, which the bird spreads across the feathers during grooming. Due to this, the beak, neck, casque, tail, and wing feathers have yellow to red colour (Lim et al., 2020). The only differences between males and females are that the males have red irises while the females have white ones, and males also have significantly longer bills and casques (Paruchuri, 2011).
Buceros bicornis has a loud voice, but not during nesting season. 'Roaring' and 'cackling' are the sounds they make. The loudest voice is heard when the Great Hornbill has a large number of individuals in its night roosts. The shelter is a place for the "information center", where they will exchange information to inform about the suitable feeding location. In general, the Great Hornbills are mainly frugivores. Their diet consists mainly of fruit including figs (Ficus spp.). Among the fruits consumed are Meliaceae (Aglaia, Dysoxylum, Chisocheton spp.), Annonaceae (Polyalthia spp.), Lauraceae (Cinnamomum spp.) and Myristicaceae (Horsfieldia spp.). However, they also occasionally prey on small birds, small reptiles and insects (Paruchuri, 2011; Poonswad et al., 2013).
Great Hornbills are monogamous and have a unique breeding behaviour. Generally, hornbills are not able to construct their own nest like other birds. They depend on naturally occurring tree cavities or those made by other animals such as the Malayan sun bear, woodpeckers and barbets. During their breeding season which occurs from February and June, the Great Hornbill pair will search for a suitable tree cavity in tall, old-growth trees after courtship. Once located, the female will enter the cavity and begin sealing the entrance of the cavity with her own faeces or regurgitated food/fruits leaving a small slit to all for food transfers and ejecting faeces outside. The male occasionally helps with cavity-sealing work. After this process, the female begins laying eggs. For large hornbills like the Great, a pair usually produced a single egg/chick, or two at most. The entire nesting cycle takes about 100 to 140 days in the wild to complete. This cycle is reportedly shorter for Great Hornbills in captivity. (Kemp, 1995; Poonswad et al., 2013).
Poaching/hunting and habitat loss are the main factors that threaten Great Hornbills across its range countries. Great Hornbills are now globally threatened with the status of Vulnerable in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species (BirdLife International, 2022). Great Hornbills are listed as a Totally Protected Species in the Wildlife Conservation Act 2010.
To retain the extant population of Great Hornbills in range countries, several priority conservation actions need to be undertaken. Remaining, intact, old growth forests where Great Hornbills are found need to be protected to prevent from further loss and fragmenting. In Peninsular Malaysia, Important Hornbill Landscapes (IHL) can assist in determining key sites for conserving Great Hornbills and their forest habitat (Yeap & Perumal, 2020). Poaching and hunting need to be addressed strictly through law enforcement and prosecution. The involvement of local communities and indigenous peoples that live in or near forests with Great Hornbills can be engaged in conservation as forest and/or hornbill guardians, working alongside government counterparts (BirdLife International, 2022).
