The Hornbill

Published on: 08/07/2022

Photo title: Yellow-billed Hornbill

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Photo Credits: Daniel Crous

Evolution is a fantastic concept. Throughout the worlds natural areas people immerse themselves in the wonders of evolution, reveling in the skill with which it has crafted shapes, colours, characteristics and pretty much everything else. Evolution is defined as; “the process by which living organisms have developed from earlier forms during the history of the earth”. Natural selection may be seen as the primary tool used by evolution to guide the development of different species in their respective directions. Natural selection ensures that the evolution of each species is always towards a more favourable outcome. Basically, what this means is that on a biological scale, the natural world is embroiled in a constant state of warfare, with each species trying to outcompete the other. Animals and plants grow defense and attack mechanisms, tools for better gathering of food or for better defence of territory. Predators develop hunting advantages, prey animal counter these with defense mechanisms of their own. It is constant and always at play all around us, almost as though a global cold war is in motion, with each entity working on itself without really firing shots at others.

I love to challenge myself, when I find something in the wild that is intriguing or seems out of place, I like to find out exactly how and why such a thing exists. Evolution through natural selection is almost always part of the answer. Take for example the comical Hornbill, the obvious feature on this charismatic bird is the overly large bill. Heavy, large and attached to the front of the face, that bill cannot be easy to handle and surely tips the scale unfavourably on size versus usability. The hornbill doesn’t need the large bill for feeding, nor does it really use it much for defense of itself or territory, though it can be formidable weapon. Why then do hornbills across the globe carry such a large beak? The answer arrives when you delve a little deeper. Hornbills nest in holes in trees, usually a space cleared out by another animal and then taken over by a breeding pair. The pair of hornbills inspect the hole thoroughly, identifying every entrance and exit point. They clean out the interior and start to line it with feathers and fluff. Once the interior is complete they fetch mud from the nearest water source and pedantically plaster up all but one of the nests entrances.

Tockus leucomelas -Kalahari Desert Botswana -8

Photo title: Yellow-billed Hornbill

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Photo Credits: Daniel Crous

Here it gets interesting, the female bird now climbs into the nest where she will remain until the chicks are hatched and ready to leave. The male bird closes the female into the nest with plastered mud, until only a small circular hole remains, just the size of the birds beak. The female remains safely sealed into the nest, with only a small hole to defend against predators such as lizards and snakes. The nest is well regulated in temperature and is entirely weather proof and safe, perfect for a batch of ungainly chicks to gain their strength in. The male hornbill goes into over-drive, he spends almost every minute of daylight catching food and bringing it back to the nest where the female is entirely reliant on him for sustenance. He now needs to feed himself, his mate and all of their chicks. If he cant, they will perish from starvation inside their tomb. Using his perfectly adapted bill, he passes crickets, worms, mice, and anything else he finds through the hole to his family. When the chicks have grown to a suitable size to start learning to fly, the male and female break down the nest they spent so long assembling, releasing the young family from their prison. The young chicks now perch on the edge, starting to take their first awkward flights, they need to learn to fly with a large horn between their eyes!

This wonderful sequence of evolution, carved from natural selection is taking place all across the Kalahari and southern Africa during summer. With the abundance of summer food, it is the only time the male hornbill would be able to find enough food to keep his family alive during nesting. So, one day, while reading a book in front of your tent in the Kalahari, you may notice a hornbill busily flying back and forth along a certain route. On closer inspection you notice he is picking up ants from a source he has found and is carrying them back to a specific tree. When he lands in the tree a peculiar beak shape pokes out of the tree to take the offered food. You have found his nest, his family and the wonderful reason he has such a large bill.

Daniel Crous

Daniel Crous has been lucky enough to call Botswana home for his entire life. His folks ran safari camps in the 80's and his early childhood was spent in the heart of the Okavango Delta. Life outdoors has always been his calling, safaris in Botswana are one of the purest forms of such a life. His Dad handed him his old film camera when he was about 12, documenting the wilderness around him has grown from passion to profession. He is equally passionate about the conservation of the land we live in and all of its creatures, including its people. He now takes extreme pleasure in leading others to some of the incredible experiences available here.