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!"
This time I’d like to tell you more about that most maligned member of the swine family (or Suidae in Latin), the Warthog! It is often called ugly, and yet it has its own kind of charm. They must be beautiful to themselves, at least! Me, I love them; and baby warthogs are certainly cute! Its name in Afrikaans is ‘Vlakvark’ which means ‘Plains Pig’.
I include for you something I hope you find interesting. Some years ago I found a warthog’s skull in the bush during a nature exploration. It was quite clean and also complete, with lower jaw, only missing the lower front teeth and one lower canine, so I took it home. I used it for an art concept that I call a ‘Skullscape’ – you can see it at the end of this article.
There are actually two warthog species. This is the common warthog, Phacochoerus africanus, which is widespread in sub-Saharan Africa, except for the rainforest belt and the desert regions of southern Africa and northeast Africa. In those two desert regions the other species, the desert warthog Phacochoerus aethiopicus occurs or used to occur … the southern population has gone extinct, so only the northeast African ones remain. They are similar enough to be virtually indistinguishable in the field, only details of the teeth and jaws differentiating them from each other. Only the common warthog occurs in South Africa, and it is indeed common in the bushveld, being easily seen in most of the game reserves in the North and East of this country.
Warthogs are of course characterized by their warts! Underneath the eyes there is a pair of sideways projections, sometimes reaching almost 15 cm/6” in length. In the boars there is a second, smaller pair of projections further along the snout. These are not really warts, but are connective tissue covered in thickened skin, the ones on the cheeks also being supported by bony projections of the skull. Their function is protection of the eyes and face, often from other warthogs, since males fight each other face-to-face using their wickedly curved, sharp tusks! These tusks are the second most striking feature of warthogs. They are the canine teeth, which are the eye teeth in humans, and the sharp biting teeth in dogs, cats and other carnivores – in fact most mammals have them. The warthog’s upper canines are the longest, and curve outward, upward and, when sufficiently developed, inward again. The lower canine fits snugly below the upper when the mouth is closed, and is smaller, only following the outward curve of the upper canine for a short distance. But the lower canines continually rub against the uppers in a way that whets them to a deadly sharp edge and point! So they are in fact the more dangerous. Warthog boars have more pronounced ‘warts’ as well as longer tusks than sows.
In other respects warthogs are more typical members of the pig family. They have the typical large head carried on a short, very thick neck. The tip of the snout is the typical round, flat, mobile disk, called a rhinarium, shared by all extant members of the pig family. In the warthog this rhinarium is turned downwards, so that you rarely see it straight-on as you could with a domestic pig. The warthog also uses this for rooting around in the soil, although it doesn’t do this as much as other pigs do. The warthog has the typical barrel-like porcine body, but wild ones are never fat like domestic pigs are (which is true of other wild pig species also). The body is sparsely covered in coarse, bristly hair apart from the mane and ‘beard’ (see below). A warthog boar can reach 85 cm/33” at the shoulder with a bodyweight of 150 kg/330 lbs; the sow is smaller, reaching 75 kg/165 lbs in bodyweight.
Then there are a few other unique features of warthogs. Their legs are quite slender, and they are indeed fast runners. They have long, thin tails with a tuft of hair at the tips, and whenever they break into a run the tail goes straight up like a flag. Indeed it has a similar function, being a signal to other warthogs that there’s danger to run away from. It also certainly helps wartpiglets to follow their mother in long grass. There is a prominent, erectable mane of long hair from the top of the head down the neck and over the back. There is also a ‘beard’ or set of whisker-like bristles growing along the side of the jaw. My pencil sketch illustrates one with a particularly fine mane and facial hair. Warthogs have eyes set very high on their skulls, right at the top in fact. Because their necks are so short and thick they cannot lift their heads very high, so having eyes as high as possible on the skull gives them the best view over the tops of the tall savannah grasses. They still don’t have great visual acuity, instead listening to the calls of the oxpeckers (tick-and-flea-eating birds) that attend them to warn against approaching predators.
This is a pig that has become specialized for a lifestyle in open savannah. All other pigs (except for the closely related desert warthog) inhabit forests. Becoming specialized for grazing has involved changes to their teeth, the last molars having become longer, deeper and more durable, taking the burden of chewing the tough grass. Warthogs can tolerate hot and dry conditions quite well, not needing access to drinking water, but they do appreciate mud to wallow in, which helps protect their skins from the intense tropical sun as well as from parasites. Although warthogs eat a lot of grass, including grass roots that they uproot with their snouts, they also eat herbs, the leaves and bark of some shrubs, succulents, berries, fallen fruit and some animal foods … they have been known to scavenge carcasses. Mostly they prefer fresh, short grass, for instance sprouting after a bush fire or growing in a moist place beside a river, but they’ll also strip off the flower- and seedheads of taller grass. Feeding or rooting they often ‘kneel’ which as I’ve said in the entry on the Red Hartebeest actually means they go down on what in us humans would be the wrists. They develop thick, prominent callouses on their wrist joints as protection against skin damage from all this ‘kneeling’. They ingest a lot of soil, from which they perhaps derive some much-needed mineral supplementation; they’ve also been seen chewing on bones.
For shelter, warthogs retreat into holes. They may use natural cavities or often take over old aardvark burrows, sometimes widening them with a bit of their own digging; they can dig such holes by themselves if nothing convenient happens to be available. A warthog exits its hole face-first of course, but also it enters the hole by reversing into it so its head with its deadly tusks still face outwards, so as not to present any vulnerability to a predator. Any predator, deciding to explore a hole and small enough to fit into it, would quickly realize its mistake when coming upon a set of warthog tusks, not to mention the living hog backing them up, a distance down. But with a lion it’s a different matter: they’ve been known to dig warthogs right out of their holes and kill them. But this is very difficult with sufficiently deep holes. For the warthogs these holes also provide welcome shade during the hottest savannah summer days, as well as protection against the cold during some of the winter nights in the higher or more southerly parts of their distribution. Warthogs will drag dry grass into their burrows to provide better insulation.
The burrows are also safe places for raising a family. Family is important to warthogs: a sow and her offspring (the males while they’re still immature but the females for much longer) will remain together and sometimes link up with other family groups, often relatives of theirs. These extended families will have territories averaging 4 square km/about 1.5 square miles within which there may be as many as 100 different burrows, only a few being in active use at a time. Warthog families will rotate their use of the holes, never living very long in any particular one. Adult boars don’t remain long with their families, though; they typically wander around solitary, fighting each other for access to sows. A boar that has managed to establish his dominance will seek out a sow in estrus and court her by champing his jaws, grinding his teeth, drooling, and making ‘chug-chug-chug’ steam locomotive noises. She will play hard to get, running away at first, but usually she cannot resist his dashing good looks and his charming performance for very long, and will eventually relent. The boar might hang around her for a while after they mate, helping defend her in her pregnant state, and afterwards their children while they’re still small. Her gestation lasts up to 170 days at the end of which she gives birth to two to eight piglets. Unlike other wild piglets, which have very pretty stripey coat patterns, wartpiglets are plain brownish. They grow quickly, beginning to graze at three weeks and weaning between 2 to 6 months’ age. They follow their mothers, often trotting in a straight line behind her, their tails raised high just like hers. Typically she will chase them away when she falls pregnant again. Her sons might then form small bachelor herds that stay together until they mature at the age of four years, while her daughters might go on to form families of their own. But if she miscarries or loses some of her babies she will welcome her ‘old’ family back again – the girls, at least, which may remain with her until they’re three years old. She will also sometimes adopt and suckle foster piglets. If all goes well for them warthogs can live for 18 years.
Although, as I’ve said, a warthog in its burrow is safe from most predators, out in the open they can be caught by the larger ones such as lions, hyenas, leopards, crocodiles, wild dogs and cheetahs. But the babies can be caught by a variety of smaller predators and even large eagles and owls. In general the species’ survival can be considered safe at the moment.
The pig family today is more diverse than most people, being acquainted mainly with domestic pigs, realize. There are a few more species in Africa which I also hope to feature in this column for you, and there are several species in Asia. In the past, though, pigs were extremely diverse. Their fossils seem to have preserved well; pig skulls and especially pig teeth are some of the most abundant mammal remains in fossil sites in Africa, Europe and Asia. The family doesn’t seem to have made it to the Americas but there they are replaced by the very similar peccaries. The warthog belongs to a lineage of African pigs that have produced some very striking species, such as Metridiochoerus which had very long, fairly straight tusks, varying from pointing sideways to apparently facing forwards in some species. Then there was the more distantly related genus Notochoerus which reached the size of a rhino! Another strange prehistoric pig was Kubanochoerus, found in Africa and Eurasia. This one didn’t have particularly large tusks, but instead had a prominent, forward-pointing bony horn in the centre of its forehead! There were other pig-like prehistoric artiodactyls (even-hoofed mammals) that are sometimes called giant pigs, the Entelodonts, but these actually constituted a quite different family that is completely extinct today. Modern pigs are intelligent, versatile and adaptable, and might over coming millennia (provided we humans don’t totally trash the Earth) diversify into many new, fascinating species.