THE ROBINSON LIBRARY
|The Robinson Library >> Order Coraciiformes|
Buceros bicornis (aka Concave-Casqued Hornbill, Great Indian Hornbill)
One of the largest members of its family, the great hornbill is 36-48 inches long, has a wingspan of 60-70 inches, and weighs about 6.6 pounds.
Vividly colored and easily recognizable, it has a black face, chin, back and lower breast, the back with a metallic gloss. The crown, neck, upper breast, lower abdomen, thighs, upper- and under-tail coverts are white. The wings are black with white tips to the greater and median coverts forming a white band across the wing, and white tips to the primaries and secondaries, forming a white terminal band.
Males and females are similar except that the irises of males are red while those of females are white, and males have slightly larger bills and casques.
Distribution and Habitat
Great hornbills are native to mainland Southeast Asia, the Malay Peninsula, and Indonesia, and are breeding residents in Bhutan, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Thailand and Vietnam. In India, they and several other hornbill species live in the Western Ghats mountain range and forests in both the northeastern and southern regions.
They live mainly in wet, tall, evergreen forests. Old-growth trees that extend beyond the height of the canopy are preferred for nesting. The height of the tree and the presence of a natural cavity large enough to hold a female and her eggs are more important than the type of tree. They can be found at elevations of up to 6,600 feet.
Great hornbills are feed primarily on fruits but will take small mammals, birds, amphibians, reptiles, and insects as well. They can use the tip of their bills as fingers to pluck fruit from trees or animals off of the ground, and the edges of the bills are notched like a saw for grasping and tearing. They are especially fond of figs, and great hornbills have been known to protect fig trees from other birds.
Male casque size is important in attracting and fighting for mates. Males compete for females by butting into each other in the presence of a female prior to the breeding season, probably as a display of superiority in competition for a mate. Mates, or potential mates, also perform duets where the male calls, the female replies, and they continue on in a loud volley. Once formed, a breeding pair remains together throughout their lives.
During the breeding period, which lasts between February and May, the pair chooses a tree in which to lay the eggs. This tree is usually a very tall, old-growth tree and the same one is used every year if possible. After finding a hole in the tree that is large enough, the female uses both her own feces and her mate's to cover the entrance from the inside, thus confining herself inside. She makes a small slit through which the male provides food. While inside the hole, the female lays and then incubates on average two eggs. The male provides the female with both whole and regurgitated fruits during the incubation period, which usually lasts between 38 and 40 days. Protected within the tree, the female completes a full molt which renders her flightless for a period of time.
After the chicks hatch, the female remains confined in the tree for around five weeks, when she emerges to help the male gather food for the growing young. The young re-seal themselves within the cavity after the female leaves. For the next two weeks, both parents provide food for the young. After the young emerge, the parents continue to feed them until they reach roughly 15 weeks of age, at which point they are considered independent.
Great hornbills can live 35-40 years in the wild.
Great hornbills tend to stay in small groups of monogamous pairs and their offspring. They are active during the day, and at night they gather in large communal roosts which may contain hundreds of individuals. Great hornbills are most vocal within these roosts, which are thought to be "information hubs" where individuals can share information regarding good feeding sites, nesting trees, etc.
A non-migratory species, the great hornbill generally moves within an area of about 5.5 square miles.
Except for the time during nesting season, great hornbills vocalize very loudly. The sounds they produce can be described as "cackling" or "roaring." The location of individuals can be identified by sound alone due to their vocalizations combined with the characteristic "whooshing" sound produced by their flight. This unique flight sound is produced from the lack of flight feather coverts.
|The Robinson Library
>> Order Coraciiformes
This page was last updated on June 20, 2018.