Colours of Wildlife: Crowned Hornbill

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Crowned Hornbill

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!"

Crowned Hornbill by Willem.


Today I bring you another close-up bird portrait. This is a Crowned Hornbill, Tockus alboterminatus (or Lophoceros alboterminatus). If you've kept up with this column, you'll have seen many hornbills already. They're really some of my favourite birds, and we're blessed with several species here in South Africa. What's interesting about the hornbills of Africa, is that most of its hornbills are quite small compared to the ones in Asia. Also, the small hornbills of Africa are often savannah-dwellers rather than rainforest denizens. Lastly, they're also not quite as beautifully and boldly coloured as the Asian ones. Many of the Asian hornbills actually use 'make-up'. Their bodies make a colourful oil that they exude from their preening glands on their rumps. They rub their bills on the glands, which transfers the colours to their bills, and then rub their bills against their feathers. This way they add yellow and red tones to the whites of their plumage.


As far as I know, this phenomenon doesn't occur in any African hornbill. Thus, the plumage of our hornbills lack the red and yellow hues, instead mostly being black, white, and brown. The crowned hornbill is typical in this respect. Its body is mainly dark brownish grey, relieved by a white belly, and tips to the outer tail feathers. It also has white streaks above and behind its eye, and a crest of shaggy feathers. But it has a colourful bill. This is bright red, with a bright yellow base. These colours are inherent to the bill, not the result of tinted oils. It has a striking yellow eye as well. The crowned hornbill also has a ridge on the upper bill, larger in the male than in the female, stretching from the base almost to the tip. This starts to look like the much larger casques found on the larger forest-dwelling hornbills. But it is still one of the smaller hornbills, reaching a length of 53 cm/21".


Also, unlike most of the smaller hornbills, it is a forest dweller. It inhabits forest and tall, dense woodland in central and eastern Africa from Ethiopia down to South Africa. In fact, it is the most southern-occurring hornbill in the world, entering the forests of the Eastern Cape, though apparently not abundant in the Knysna-Tsitsikamma forests. They occur in pairs or small groups, numbering up to seven birds. In fine forest habitat they are resident year-round, but in woodland experiencing a particularly dry season, they may move out to lusher habitat. In some regions of East Africa they may be regular migrants.


In the forest, the hornbills choose roosting sites. These are usually long, horizontal, bare branches with clear views above, below and to the sides. They also favour perches over water and/or in a sheltered valley. Each group may have up to six roosting sites in its territory. The hornbills will be careful when approaching their roosts, first checking for predators such as hawks. If they spot one, they will utter an alarm call and dash for cover. They will take their perching places as the last light of the day disappears, spend the night and move out again to feed the next morning.


Crowned hornbills are omnivorous. They eat plenty of fruits from tall forest trees. These they pluck from twig tips using their bills, sometimes even as they hover in flight. They eat plenty of invertebrates as well, including ones avoided by most other birds, such as poisonous caterpillars and grasshoppers. They squeeze these in their bills and wipe them against branches to get rid of the noxious juices. They even eat some vertebrates, such as baby birds of other species, or small lizards, snakes and even mammals such as golden moles. Bits that they can't digest, such as seeds or hard insect exoskeletons, they regurgitate in pellets almost like those of owls.


Like other hornbills, these need holes in trees for their breeding. They are thus dependent on mature forest where there are trees large enough to have suitably-sized cavities. They form loyal couples. A pair will defend a territory about two hectares in size. They display around their nesting sites by uttering their whistling calls, pointing their bills upward and rocking forward and backward with each whistled phrase. As the breeding season approaches, the male will start bringing food to the female to assure her that he will provide for her; she will inspect the breeding cavity and seal visible cracks; finally she will seal herself inside, leaving only a narrow slit through which the male passes food to her. She uses her droppings and a variety of debris such as pieces of bark, insect remains or fruits as the sealing material. The male will bring her things like bark flakes, flowers and snail shells as material for lining the nest. She loses the flight feathers of her wings and tail, growing new ones through her incarceration. She lays two to five eggs, usually late at night. They're laid at intervals so that the chicks are of different ages. The egg shells are thrown out after the chicks hatch. The male now has to provide for the chicks also. About a month after the first chick hatches, the female, now with wings and tail regrown, breaks out of the nest. From here on, she helps the male feed the chicks. If there's not enough food, it's usually the youngest, smallest chicks that die. The chicks finally break out about fifteen days later. They may stay with the parents for six to eight months, but at the onset of the next breeding season, they move away, forming temporary small flocks or eventually finding their own mates and establishing their own territories.


At present, crowned hornbills are still widespread and reasonably common in suitable habitat. They're thus not considered endangered.

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