Great Pied Hombill

Abstract

The Great Pied Hornhill Buceros bicornis is one of the largest and best known of all the true hornhills. In recent years, this species has been called the Great Indian Hornhill. The scientific name "bucerus" means "having ox's horns." This species of hornbill has a large block-like casque above its mandibles. It has a hlack line at the junction to the hill itself. In adult males, the casque is double pronged in the front and ranges from mostly yellow to redorange in color. In adult females, the casque is smaller and lays parallel to the mandihle. The eye coloration in males is red while the eyes of the female are white.

The Great Pied Hornbill ranges from northeast India along the base of the Himalayas to Assam, China, Viet Nam, Laos and Cambodia. It ranges south through the Malay Peninsula to Indonesia including Sumatra and many other islands as well as. There is also an isolated population in India following the southwestern edge of the peninsula.

There are 54 recognized species of hornbills (Kemp, 1995) which are divided into two genera, Buconndae, the ground hornhills (two species) and Bucerotidae, the true hornhills (52 species). All hornhills belong to the order Bucerotiformes. They were originally classified in the order Coraciiformes which now include the kingfishers, rollers and bee-eaters.

The hornhills are unique among all birds in that the females, from within the nest, seal up the entrances to the point where only a narrow vertical slit remains. Through this slit, the females, and later the young, are fed by the male. Old food and feces are discarded out through this slit. During this time of concealment, the females of most homhill species molt their flight feathers which grow in again hefore the bird leaves the nest. During this time she will incubate her eggs and

brood her chicks. An exception to the rule, the two ground hornbills do not seal themselves into nests.

Hornhills, as a group, have a geographic distribution that includes subSaharan Africa, India and much of southeast Asia including Indonesia and New Guinea. All hornbill species are omnivorous in their dietary habits with the two ground hornhills heing mainly carnivorous while one other group, Aceros, is mainly frugivorous (fruit eating).

Hornbills are an Old World order and though the toucans of Central and South America fill the same ecological niche, they are not closely related. This is specially true in their breeding biology.

The Great Pied or Indian Hornbill has been exhibited in zoos for many years. They are very hardy after they are acclimatized, hut care must he given where temperatures become so low that frostbite may cause damage to their toes or even their hills. But the cold weather is not ideal if reproduction is a goal.

I do not know when the first captive breeding of the Great Indian Hornbill was accomplished, but there is an early account of a successful breeding of this species at Jurong Bird Park in Avicultural Magazine 0978) by P.K. Choy, the Director. Another success

was at the St. Louis Zoological Park in the Aoiculiural Magazine (1987) by Bruce Bohmke, then Curator of Birds.

These are two excellent accounts of successful reproduction in captivity. Artificial nests are supplied and this seems to be a great stimulus for bonded pairs of hornbills. Great care is usually given to avoid disturbing the nest once the female has sealed herself inside. Recent studies now show that this may not be as important, but the male should generally be kept away during nest inspection as he can cause quit a disturbance. Most first-time nests, however, are not disturbed even though there is the urge to check for fertility or to see if there are any chicks.

Pair bonding appears to be very important in the success of hornbill reproduction, especially for the large species. Most are housed in large planted aviaries. It appears that the nest opening and where it is placed on the nesting log is very important. Having had the pleasure of listening to Pilai Poonswad of Thailand at the two Delacour/IFCB symposia 0983, 1987) in Los Angeles, has given me a real appreciation for the large Asiatic hornbills. In one of her proceedings, Pilai Poonswad has illustrated nest openings found in the wild. Most are long, narrow, vertical slots that appear like very flattened, vertical diamond shapes. Obviously, they follow the contour of the tree opening or cavity. Several zoos have modified their captive nests to follow these natural designs and their success rates have improved.