Bird of the Week – Great Indian Hornbill
Great Indian Hornbill (Buceros bicornis) – also known as Great Pied Hornbill – is one of the largest and beautiful member of the hornbill family. It is endemic to the forests of Indian subcontinent, the Malay Peninsula, Sumatra and Indonesia. This bird has a considerably longer lifespan among birds, studies confirm in India it lives around 35 years and may go upto 50 years in captivity.
The Great Hornbill is the State bird of Chin state in Myanmar, and Kerala and Arunachal in India. The conservation status of this beautiful bird is rated as ‘Nearly Threatened’ by IUCN 3.1 and is in the Red List.
Size and Colorization
The Great Indian Hornbill is a large bird with an average length of 95-120cms and a wingspan of 150cms. The average weight is measured as 2.5 to 4 kg and is the heaviest among other hornbills.
The most eye-catching feature of the hornbill is its bright yellow and black casque on top of its large bill. When viewed from front the casque appears U-shaped and from top it is bowl-shaped with two ridges along the sides that form points in the front. The casque is hollow and the purpose is unknown but some believe that it’s the result of sexual selection. Male hornbills have been known to indulge in aerial casque butting, with birds striking each other in flight.
The female hornbill is shorter than the male and has blue eyes instead of red and with the orbital skin in pink. There is a red color in the back of the casque in females while the underside of the front and back of the casque is black in males. Male has a brighter yellow beak and primaries by spreading the preen gland secretion which is yellow.
The young birds have no trace of a casque on birth, it takes about 5 long years to have a full developed one.
The wing flaps are heavy and the sound produced by birds in flight can be heard from a distance. The flight involves stiff flaps followed by glides with the fingers splayed and up-curled.
Habitat and Roosting
In South Asia they are found in a few forest areas in the Western Ghats and in the forests along the Himalayas. Their distribution extends into Thailand, Burma, Malaya and Sumatra. Their habitat is dense mature forests in high altitudes. They are highly dependent on larger stretches of forest unlike many of the smaller hornbills. The habitat lost and hunting has really affected these beautiful species.
They found to be using the same roosting sites and are very punctual. Birds will arrive by sunset from long distances, following the same routes each day. Several tall trees in the vicinity may be used, the birds choosing the highest branches with little foliage.
Food and Feeding
In the wild, the Great Hornbill’s diet consists mainly of fruit. They highly attached to Figs as a main food sources. They are primarily frugivorous although they are opportunists and will prey on small mammals, reptiles and birds especially to feed their newborns. They are normally seen in small parties with larger groups. They don’t consume water in its direct form but obtain from their diet of fruits. They are important dispersers of many forest tree species.
The Great Indian Hornbills are known to form monogamous pair bonds. Great Indian hornbill forms a pair for many years and in some cases, for the entire lifetime. They are mostly seen in groups of 2-40 individuals.
Their nesting behavior is very interesting compared to other birds. They prefer large tall trees in mature forests to build a nest. Female hornbills build nests and the opening is sealed with a plaster made up mainly of feces. Only a small slit will be there to be fed by her mate. She remains imprisoned in her nest until the chicks are semi-developed. The male feeds his family for the entire period until their chicks are ready to take off.
During the breeding season they become very vocal. They make loud duets. These calls begin with a loud “kok” about once a second given by the male and joined in by a female. The pair then calls in unison turning into a rapid mixture of roars and barks.