Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"

Here's another hornbill for you, this time a Black-casqued Wattled Hornbill, Ceratogymna atrata. This is a species I haven't seen yet, as it occurs in rainforests in equatorial Africa, where I haven't been yet. It is Africa's second-largest true hornbill, only the Yellow-casqued Wattled Hornbill being bigger. It reaches 90 cm/3' in total length, and a weight of 1.6 kg/3.5 lbs. The two species of ground hornbill are much bigger, but they belong to a separate hornbill family.

The two species of wattled hornbill are characterized by the bare blue skin they have around their eyes, and the naked skin on their inflatable throats as well as long, dangling, blue wattles, which no other hornbill species in the world have. They differ in a few details, such as the colour, size and shape of the casque, and a few features of the plumage. The black-casqued wattled hornbill has a huge, somewhat cylindrical casque on top of its bill, the largest of any African hornbill. This casque is actually slaty grey rather than black, and can look bigger than the bill itself, making up most of the volume of the head! But it is not heavy, being mostly hollow. It probably plays a role in amplifying the hornbill's far-carrying, trumpeting calls.

In the dense equatorial forests where visibility tends to be low, these calls are the hornbill's way of announcing its presence and proclaiming ownership over its territory. The trumpeting, somewhat nasal braying call of the male can be heard up to 2 km/1.25 miles away. The call of the female is not as loud or as deep. The female mostly just calls with a single wailing note, but the male also has squawking and fluty-tooting calls. Both sexes make a chuckling noise as an alarm call when they suspect danger. If they fly off, their wings make a loud whooshing noise, which also alerts other birds.

Apart from being quieter, the female of this hornbill species looks quite different from the male. Her casque is only half the size, or even less, of his, while her bill is also shorter. She also has a reddish brown head and face. Like the male, she has a crest of long, wispy feathers on her head, and she also has the throat wattle. Both sexes also have glossy black feathers on their entire bodies except for the tips of the outer tail feathers which are white. Only the central tail feathers are all-black, but this can usually only be seen in flight, not when the tail is folded closed. The female is slightly lighter than the male as well. The wattled hornbills are the most sexually dimorphic (meaning the sexes look different) of all African hornbills, in this respect resembling some of the large Asian hornbills. In those the situation is the opposite, however, in that the females tend to have black heads and necks while those of the males are buff or reddish brown. In the other African hornbills the male and female have similar plumage, the only difference, if there is one, being in the size and shape of the casque.

Like other forest hornbills, this is primarily a fruit eater. These huge hornbills usually live in pairs or small family groups of 3-5 birds. They have fixed roosts in trees, from where they fly out every day in search of food. In trees heavy with fruit, up to 40 of these hornbills might gather. They will dominate other hornbill species, but themselves will be dominated by monkeys. Favourite fruits of theirs include figs, oil palm fruits, various berries and many others. They will sometimes descend to the forest floor to pick up fallen seeds. They occasionally eat insects as well, such as winged ants and termites, beetles and caterpillars. In one nest the remains of a crab was found. They sometimes raid the nests of small birds for eggs or chicks. This hornbill needs access to drinking water, but fortunately this is easily found in the rainforest.

Like other hornbills this species nests in large cavities in trees. Not much is known of their breeding behaviour. They might nest any time of the year, there not being hot or cold, wet or dry seasons in the equatorial forests. There might be regional differences, though, in when the hornbills prefer to nest. The female enters the cavity, and then she and the male together wall it up, leaving only a small slit through which the male will feed her. In the wattled hornbills, the material for building the wall is a combination of mud, their own droppings, and sticky food items. The male swallows all this and then in his gullet forms it into sticky, round balls, which he regurgitates to the female who uses them as 'bricks' for building the wall. She remains inside while brooding the eggs and chicks, while the male brings her fruit and seeds, regurgitating them to her through the slit. She and the chicks break out at last when they are ready to face the world.

This hornbill species is not in immediate danger of extinction. It has a very large range from equatorial West Africa to Central Africa, as far east as western Uganda. It can survive in both undisturbed lowland forest as well as in some disturbed environments such as coffee, cocoa, oil-palm and other plantations. It can extend into moist savannah along the corridors of tall trees lining rivers. It is also found on the island of Bioko. In some regions it is hunted, and in others it is threatened by the felling of the forests. It is still common over much of Africa. Apart from humans, it is preyed on by crowned eagles and other forest predators. In captivity these hornbills can live for twenty years.

Colours of Wildlife Archive

Willem

05.05.14 Front Page

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