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!"

The Zebra Duiker, Cephalophus zebra, is one of the prettiest antelopes in Africa. Its name reflects its neat black stripes. It is in no way related to zebras – except inasmuch as both are placental mammals! Its genus name, Cephalophus, means 'crested head'. This refers to a tuft of hair that most duikers have on top of their head between their horns. But the zebra duiker doesn't have such a tuft, the hair on its head being short and dense as on the rest of its body.

The duikers are a tribe of antelope, the Cephalophini, only found in Africa. This is a diverse group, but easily recognizable. The name, meaning 'diver' in Afrikaans, refers to their diving into dense vegetation to flee from humans and predators. It is difficult for English speaking people to pronounce but you can get close enough if you say 'doiker'. Most duikers are small, only the very largest species such as the Yellowbacked Duiker reaching medium-size. They have stout, compact bodies with arched backs, carried on thin legs. They have simple, short, straight horns. The probably closely resemble the ancestors of all bovids – that is to say the ancestors of all antelopes, cattle, sheep and goats. They also have prominent scent glands below their eyes, that exude gooey stuff that they rub on twigs and branches to mark their territories. Most duikers are forest dwellers – in some forests several different species occur together, partitioning their lifestyles by exploiting different foods and sections of the forest and being active at different times to avoid competing with each other. They have large and complex brains. Duikers are interesting among antelope in that they will eat meat: they will scavenge carrion and on occasion even catch and eat birds and other small animals. There are 21 recognized species at present, but new discoveries are being made – Walter's duiker, Philantomba walteri, was described as recently as 2010. Many duiker species are rare and endangered.

The zebra duiker can be considered one of the endangered ones. Its natural habitat is moist rainforest in western-equatorial Africa, where a massive amount of deforestation has already taken place and the surviving forest has been divided into man smally patches. Zebra duikers can live in forest that is re-establishing itself after having been cleared, but is very vulnerable to predators and hunters in open habitats. It mostly lives in the lowlands although in a few places it ranges into low mountain forest.

Zebra duikers are unusual in that the males as well as the females sport the short, stout and very sharp horns. As in other duikers these are positioned well back on the head and pointed to the rear. They also have very thick bones at the front of the skull and face. Like other duikers they have a large facial scent gland. They have additional glands at the heels of their hind legs and in their groins. They have large, moist snouts, large eyes as well, but their ears are small compared to those of more open-living antelopes. Among the duikers this one falls about in the middle size-wise, reaching a shoulder height of 40-50 cm/16"-20", and a body weight of 20 kg/45 lbs. The female is slightly larger than the male, but the male usually has slightly longer horns.

The thick skull of the zebra duiker might be an adaptation for breaking open the hard shells, crusts and rinds of large forest fruits, which they butt with their heads and snouts. Fruit is a major part of this duiker’s diet. It is dependent to a large extent to monkeys, fruit bats and birds for dislodging fruit from the canopy so that it can pick them up off the forest floor. In eating these fruits, these duikers actually perform the trees a service. The seeds are adapted to have hard coatings, so that they can pass through the duiker's digestive system intact. But the acid, digestive juices and warmth weaken this coat so that the seed can germinate more easily once it comes out. And in the duiker's faeces it can sprout and has a good dollop of fertilizer to give it a head start. If such seeds are not eaten they have a much poorer chance of germinating and establishing themselves. Apart from fruit these duikers also feed on fallen flowers and leaves.

Another possible use for the thick skulls is that zebra duikers head-butt each other in their displays. This might be males fighting males for territory, or for access to females. But as the female also has the thickened skull and the horns, she also most likely takes part in defending herself, her territory and her mate. The short horns are not very dangerous, but still the duikers often end up with scratches on their heads and faces. When a female accepts a male they form a closely bonded pair. They stay close together and lick and rub against each other, smearing their scents all over each other to strengthen the bond.

The conspicuous stripes of this duiker might be to break up the outline of the animal's body, making it harder for a predator to get a fix on it. It might also be an adaptation to enable a pair to easily see each other in the forest. They might also help youngsters to stay in touch with their mother. These small antelopes are slow breeders. They only get a single lamb at a time, after a gestation of 220-230 days. For the first three weeks of its life its mother will 'park' it in the forest, safely hidden in a dense clump of vegetation, while she goes out to feed. The juvenile is rather bluish in colour, the rich golden-reddish brown coloration starting to emerge at the age of two months. It reaches adulthood in about nine months although the male reaches sexual maturity only after two years.

Many duikers of central Africa are hunted heavily by humans, this being a serious threat to their continued existence. Duikers are in fact a staple of the 'bushmeat' trade, along with many species of monkey. This duiker, however, is so adept at hiding from humans that it is rarely hunted. It is much more at risk from the continued destruction and fragmentation of its forest home.

Colours of Wildlife Archive

Willem

15.07.13 Front Page

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