Hornbills (Family Bucerotidae) are a group of birds whose bill is shaped like a cow’s horn, but without a twist, sometimes with a casque on the upper mandible. Frequently, the bill is brightly colored.
Both the common English and the scientific name of the family refer to the shape of the bill: “buceros” being “cow horn” in Greek.
The Bucerotidae family includes 57 species. Nine of these species are endemic to the southern part of Africa. Their distribution ranges from Africa south of the Sahara through tropical Asia to the Philippines and Solomon Islands. Most are arboreal birds of dense forest, but the large ground hornbills (Bucorvus), as their name implies, are terrestrial birds of open savanna.
The female lays up to six white eggs and, during incubation, the female (of all species except the two ground hornbills) is locked within the nest cavity by a wall made of mud, droppings and fruit pulp. There is only one narrow aperture, big enough for the male to transfer food to the mother and the chicks. When the chicks and the female are too big to fit in the nest, the mother breaks out and rebuilds the wall. Then both parents feed the chicks. In some species the chicks themselves rebuild the wall unaided.
Hornbills are omnivorous birds, eating fruit, insects and small animals.
In the Sibley-Ahlquist taxonomy, hornbills are separated from the Coraciiformes, which also includes kingfishers, bee-eaters and rollers, as a separate order Bucerotiformes.
Some species have different plumages for each sex. The blue throat of the Abyssinian Ground Hornbill pictured here shows it to be an adult female.
Most species’ casques are very light and contain a good deal of air space. However, the Helmeted Hornbill has a solid casque made of a material called hornbill ivory, which the Chinese valued greatly as a carving material, as did the Japanese, who often used it to make netsuke.
PHOTO CAPTION: Abyssinian Ground Hornbill (Bucorvus abyssinicus)