Hornbills are distinctive birds with large, brightly colored beaks that set them apart from every other order of birds. The 54 species of hornbills are classified in the order Bucerotiformes and divided into two families. In other classification systems, they are included in the Coraciiformes and the family Bucerotidae. All hornbills are found in the old world, from Africa to India and across Asia. There are no hornbills in the Americas, where their niche is filled by Toucans, or in Australia. Across their distribution, hornbills occur in many different habitats, from deserts to rainforests. Most however occur in tropical and subtropical forests. Two of the species are ground-dwellers ( the Abyssinian and the Great Southern Ground Hornbill) and the rest are arboreal. These include the black hornbill and the rhinoceros hornbill.
Their strange horny beaks are used to gather food, allowing them to get prey items at the ends of branches which they otherwise would not be able to reach. Hornbills are omnivorous and will eat both plant and animal matter. Some have specialised to become exclusive insectivores or frugivores or predators of small mammals and reptiles, while others are generalised feeders and take what they can get. In general the birds that live in deserts and open country are carnivorous or insectivorous, while the frugivorous species live in the forests. However some insectivorous species also live in the forests. The beaks are enhanced in many hornbills with the presence of a large structure on top of the beak known as a casque. It gets larger as the bird gets older and may be an indication of sexual maturity and dominance.
For the most part hornbills are medium sized birds, but the largest, the Great Southern Ground Hornbill, stands a meter tall. In general, the males are larger than the females. Both sexes are noisy social birds and they often travel in large feeding flocks. However they are monogamous and the mated pairs have a very different breeding and rearing strategy to most birds.
The female hornbill seals herself in a cavity in a tree or a rock and leaves only a small opening through which her mate feeds her and the young. This provides protection from predators but the nest crevice does become rather filthy over the period in which she is locked in. The male has a huge workload gathering enough food to satisfy both the female and their brood. Sometimes he is assisted in this task by older offspring.
The female starts incubating as soon as the first egg is laid. so incubation time is increased from the time the first egg is laid till the time the last egg hatches. Larger species lay fewer eggs, usually only one or two, while smaller species have been known to lay up to 8 eggs. Incubation and rearing also takes longer in bigger birds and in the largest species, the young do not mature sexually for several years.
A number of hornbill species are now kept in captivity. They are large birds so they need large aviaries and they are long-lived so people need to consider whether they have both the time and the room to keep these active, intelligent birds. http://wn.com/Avicultural_Society_of_America has information about keeping these birds.
Hornbills, being large birds, need large areas of habitat in which to feed. As such they are threatened by activities such as land clearing and deforestation. They are fascinating birds with colorful and unique life styles that deserve our protection.
For more information: http://www.earthlife.net/birds/bucerotiformes.html http://creagrus.home.montereybay.com/hornbills.html
