The Helmeted Hornbill - A Large and Bizarre Bird of Asian Forests

The helmeted hornbill is one of the most bizarre birds in existence. The bird has a huge bill, which is red or yellow in color and has a large, solid protuberance called a casque on the top. The helmeted hornbill also has a big patch of featherless, leathery skin on its neck, which is blue in females and red in males. The birds are mainly black in color, but the belly and leg feathers are white, and the tail is white with a black band near the end. There are tufts of brown feathers extending from the back of the eyes, and the central tail feathers are almost as long as the rest of the body.

Some aspects of the hornbill's behavior are also very strange. Its call is a noisy series of hoots followed by a laughing sound which is often described as “maniacal”. The birds - especially the males - perform dramatic aerial displays that frequently end in noisy collisions as the casques of different birds collide. The force that's created sometimes pushes the birds backwards, and they need to regain control of their flight. During nesting the female is sealed in a tree hole with a plaster made of some combination of mud, clay and sticky fruit, leaving only a small opening so that the male can feed the female with regurgitated food.

Helmeted hornbills (Rhinoplax vigil, or Buceros vigil) live in evergreen forests of Southeast Asia, in Myanmar, Thailand, Malaysia, Sumatra and Borneo. Males weigh about 3.1 kilograms (or 6.8 pounds), while females weigh around 2.7 kilograms (5.9 pounds). The total body length, including the tail, is about 1.6 meters, or a little over five feet. The helmeted hornbill population is categorized as "near threatened" by the International Union For Conservation of Nature (IUCN).

The diet of helmeted hornbills consists mainly of fruit, especially figs. They also eat small animals, including mammals, reptiles and smaller birds. The hornbills use their strong beaks to dig under bark to find insects. The weight of the casque helps the birds use the beak like a hammer, while the two beak tips act like tweezers as the bird picks up food. The tongue is too short to reach food that is picked up by the end of the beak, so the food is passed to the back of the throat with a jerking motion. Helmeted hornbills prefer to forage high in the tree canopy.

Hornbills have good vision, and it's believed that they can see the tip of their own beaks, which is unusual in birds. Air rushes through their wings as they fly, making the flight a noisy event, especially when a group of hornbills are moving together. Arboreal (tree-living) hornbills hop along branches or over the ground, moving both of their feet together.

The hornbill spends part of its day preening its feathers to keep them in good condition. The yellow beak is colored red by an oily secretion from the preen gland, which is located at the base of the tail. The bird uses its beak to rub this secretion over its feathers.

The dense casque of a helmeted hornbill means that the head accounts for ten percent of the bird's weight. The aerial displays and casque collisions, often referred to as "jousting", are often seen around fig trees, which are the hornbill's favorite source of food. The jousting is thought to be a way to compete for the figs.

Males seem to joust far more frequently than females. Before he takes flight, a perched male hits tree branches with his beak and rubs the beak from side to side over the branch. He may also call. Then he takes off towards another bird, who is also flying. Loud clacks travel through the forest as the birds' casques hit each other. A bird may actually flip upside down as a result of the collision, which takes place when he is gliding rather than when his wings are flapping. After colliding, the birds return to a tree branch, and then often take off for another meeting. The displays and collisions may occur repeatedly, and the whole event may last for as long as two hours.

A breeding pair of helmeted hornbills are territorial. After courtship and mating displays the pair choose a tree cavity for a nest. The female enters the cavity and then seals the opening, sometimes with the male's help. He brings her useful materials to help her, such as mud, clay and fruit. A narrow slit is left as an opening through which the male feeds the female and the youngsters. The female stays inside the hole for several months. When the eggs have hatched and the young hornbills are old enough to be left alone in the nest, the female breaks out of the nest and then rebuilds the wall until the young are ready to fly.

The solid casque of helmeted hornbills is in demand as an ivory substitute. It’s made of a protein called keratin, which is also found in human hair and nails, as well as in mammal claws, hooves and horns. The material in the casque is often called hornbill ivory or golden jade. Hunters kill the hornbills for both their casque and their long tail feathers. The casque is carved to make ornaments and jewelry and the feathers are used to make head and clothing decorations.

Deforestation is also affecting the helmeted hornbill population, removing the trees in which it lives. The hornbills are somewhat protected from this stress, however, as they prefer to live in remote forests. Nevertheless, the population is decreasing.

There are many other members of the hornbill family of birds. They all have large beaks and sometimes have a casque. Only the helmeted hornbill has a solid casque, however - in other hornbills the casque is spongy in texture, and the beak is usually curved downwards. The function or functions of the casque are still being discovered. Its formation indicates reproductive maturity and it's usually larger in males. In at least one species of hornbill the casque acts as a resonating chamber for sound. In helmeted hornbills the casque reinforces the beak.

The first two neck vertebrae of hornbills are joined together, and the birds also have strong neck muscles. These features are thought to have developed in order to support the heavy beak.

All hornbill females incubate their eggs within a hole that is partially sealed by either the male or the female, with the exception of the two species of ground hornbills. The females of these species nest close to the ground in tree holes, earth banks or crevices in rocks. They are fed by the males as they incubate their eggs but the nest hole isn’t walled in. In addition, the ground hornbills have a slightly different anatomy from arboreal hornbills, and walk or run over the ground instead of hop. Some researchers think that since ground hornbills have important differences from other hornbills they should be classified in a different family.