Wakowwako What?

Kak-kak, Rowwow, or perhaps...Wakowwakowkow?

You know you are in the presence of a hornbill when you hear a strange but distinctive, loud and somewhat unpleasant noise(Clearly they're not passerine birds...but then, not all passerines are songbirds). That is, assuming you don't see these, often, large birds with their peculiar bills first. It is not for no reason that these fascinating birds are named after their bills.

The nitty-gritties

There are currently 54 living species of Hornbills in the world and they fall under the order Bucerotiformes which, in turn, is further subdivided into 2 families and 9 genera. They can be found from Africa all the way to Asia. They are not found in the Americas. What you can find in the Americas is the Toucan. While at first glance they may look somewhat similar, they are actually not closely related. It is possible that their similarity in appearance is a case of convergent evolution. Both birds appear to share a similar ecological niche, hence their ranges do not overlap.

Within their extensive range, they are found in a wide variety of habitats. Most occupy some sort of forest with the remaining few inhabiting the savanna or steppe. Of those found in the savanna or steppe, all but one of the Hornbills is found in Africa.

Interestingly, there is a wide range in the size of Hornbills as well- the smallest weighing around just 100g, while the largest weighs a hefty 4kg. They can all be said to be omnivorous. What differs is the proportion of their diet consisting of prey or plant matter. For some, such as the ground hornbills of Africa, mostly other small animals are consumed, whereas at the other extreme, there are hornbills that are largely frugivorous. This further attests to the incredible diversity present within the Bucerotiformes.

All hornbills form their nests in holes, preferring natural cavities. It is only amongst the hornbills that the female seals the entrance to the nest. She only leaves only a narrow vertical slit for feeding and the removal of waste. Also, the interior of the nest is not significantly altered. There is, however, an exception to this "Sealing Clause"- sealing of the entrance is not carried out by the ground hornbills.

As mentioned, these birds are relatively conspicuous. This has left them known to mankind for a quite a while and as with many(if not most) things known to the human race, we have ensured that we have found some use for them in our lives. Can't possibly just leave them be, can we? :) In the Philippines, for instance, a skull of a Great Philippine Hornbill is included in some of the ceremonial head-dresses. Also they feature in many ancient customs and myths.


Reference
Kemp, A. (1995). The Hornbills. United States: Oxford University Press Inc., New York.