Hornbills
Bucerotidae
INDEX
WHAT ARE HORNBILLS?
HORNBILL FEATURES
SOCIAL BEHAVIOUR AND REPRODUCTION
HORNBILLS, MAN AND CONSERVATION
HORNBILLS OF ARDASTRA
WHAT ARE HORNBILLS?
Hornbills are a family of birds in the same order as the kingfishers and bee-eaters, called the Coraciiformes. The hornbills are restricted to parts of Africa and Asia (old world), which is typical for most birds of this order. The hornbills are NOT related to the Toucans, which are only found in Central and South America (new world). There are about 54 species of hornbills in the world, which occupy a wide variety of habitat from the Namib Desert to the lushest S. E. Asian rainforest. They have been known to mankind for a long time and feature in many ancient customs and myths.
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HORNBILL FEATURES
Hornbills have many characteristics that make them unique and interesting birds. They are conspicuous creatures with their large curved bills, distinctive colors, varied calls and rushing wing beats. A large casque often surmounts their already large bills and it is this heavy bill characteristic that may be the reason why hornbills are the only birds with the first two neck vertebrae fused together.
Scientists are not absolutely sure of the purpose of the casque. Some postulate that it evolved to provide support for the long curved bill, which is subject to much stress as hornbills have extremely strong jaws.
The hornbills also use their bills to manipulate objects with great skill. Considering the strength of their bill, this is important when dealing with small poisonous animals, which form part of the birds' omnivorous diet. Snakes, centipedes and scorpions are caught and held in the tip of the bill, and squeezed as they are manipulated backwards and forwards. Similar behaviour occurs with fruit or seeds with hard shells, with the food being rubbed against rough bark or stone to remove indigestible material.
In addition to the practical, the bill and casque could also be instrumental in communicating the age, sex and status of a bird. The casques are usually hollow and this cavity within the casque also suggests that it could perform an acoustic function, giving resonance to the hornbills' distinctive calls.
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SOCIAL BEHAVIOUR AND REPRODUCTION
The other most distinctive characteristic of hornbills is their unique breeding habits. Hornbills are monogamous birds (stay with the same partner for life) and almost all species nest in a hollow or cavity, chosen mostly by the female, but with a little help from her partner. The female investigates cavities in trees and rocks, and once a suitable venue is found, she starts spending more and more time in it. The male brings her food, and even offers food to the empty cavity when she is not in it! Once mating has taken place and the female is ready to start laying eggs, the female moves in, and she begins to seal herself in using surrounding mud, food items and faecal material. A narrow slit is left, through which the male will feed her during her confinement.
Incubation takes 23 - 42 days, depending on the species, during which the female normally moults completely. She often keeps one eye pressed to the entrance slit, and any foreign objects are attacked, with her sharp bill.
When the chicks are ready to fly the mother will break open the cavity. By this time she has grown new feathers, and although a little stiff at first, she can fly immediately. When the chicks emerge, they can fly, but remain in the area around the nest for a few days, still being fed by their parents while they hone their flying skills.
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HORNBILLS, MAN AND CONSERVATION
Hornbills have been known to mankind for a long time and feature in many ancient customs and myths. Many Africans regard them as sacred birds and some species even thrive in very densely populated areas. Members of some West African ethnic groups used stuffed heads of ground hornbills as camouflage for stalking game and the feathers are often used for head dress adornment. Breeding individuals of some smaller species are taken for food or for the preparation of medicines. In Southeast Asian societies, the hornbills are especially important and the Rhinoceros hornbill is recognised as the god of war. Also throughout Asia, the bills have been used for making jewelry, belt buckles and ornamental carvings, which may account for why so many Asian hornbills are endangered.
Many Hornbills are relatively large forest birds and require large expanses of forest, with many old trees for nesting, in order to maintain a viable breeding population. While tropical rainforests are being felled at 95 square miles per day to supply the first world with pretty doors, furniture, scaffolding and disposable chopsticks, the future is not terribly secure for any Hornbill, or other large forest residents.
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HORNBILLS OF ARDASTRA
Ardastra has two species of hornbills; the Von der Decken's hornbill and the Trumpeter hornbill.
Von der Decken's Hornbill - Tockus deckeni
This is a small, tree dwelling hornbill, which is found from Central and East Tanzania, through Kenya to Southeast Ethiopia and Somalia. The male and female are almost identical apart from the color of the bills, the female has an all black bill and the male has an orange and red bill.
These hornbills are omnivores but their diet largely consists of meat. They will eat small animals, insects and carrion.
Trumpeter Hornbill - Bycanistes bucinator
The Trumpeter hornbill, named for its call, is also a tree dweller, and can be found in the forested regions of Africa. The male and female are almost identical, however, the male is larger and has a much larger casque, which serves as no other purpose other than ornamentation.
They are also omnivorous but their diet consists mostly of fruit.
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