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 Red Hartebeest, Alcelaphus buselaphus caama, is another species that has three scientific names, just like the Painted Reed Frog. That’s because it too is a member of a variable species with several subspecies. Hartebeests range widely over Africa with different populations being different in colour, shape and size; currently about eight different subspecies are recognized of which this one is the most southerly. The most northerly, the Bubal Hartebeest Alcelaphus buselaphus buselaphus which used to occur in North Africa, is extinct today. Some of the surviving ones are rare; the Red Hartebeest is not, fortunately.

I know these hartebeests well. There are some in our local municipal game reserve, where I frequently see them, and in many other places also. They like open landscapes such as grassland or grassy semi-desert. These are large and striking antelope exceeding 150 kg/330 lbs in bodyweight. They have long faces; indeed they typify the group they belong to, the long-faced antelopes or Alcelaphines of which the Wildebeests are also members. The long faces offset their short, thick necks, which give them an ox-like appearance. Indeed, the name ‘Hartebeest’ comes from the Dutch words ‘hert’ (deer) and ‘beest’ (cow or ox). Note: in Afrikaans we call this a ‘hartebees’ without the ‘t’ at the end, but the plural is ‘hartebeeste’. They have thick bodies set on long, thin legs, and their tails are like a hairbrush with hair only on the back side. Finally they have weirdly lyre-shapes horns set on a tall, bony ‘pedestal’ that rises on the skull above the eyes. These horns are very strange in their formation; compared to an antelope like the Impala which also has lyre-shaped horns, that of the red hartebeest is twisted right round so that they now face back to front!

Their unusual shape coupled with the open habitats they inhabit make them easily identifiable even from a great distance. They also tend to live in herds which can be quite big. If you see them up close you can appreciate their rich colour markings: the body is reddish brown, and they have glossy black on their faces, legs and tails. They are the most colourful of the hartebeests.

Hartebeests and the long-faced antelopes are interesting as a group because they illustrate rapid diversification. Long-faced antelopes have evolved fairly recently in Africa, being known from about eight million years ago which is not a long time geologically speaking, and have spread out to fill a variety of niches. They are mainly grass eaters and avoid dense forests, but several occur in dry or even desert regions while others inhabit dry woodland. Some members have spread to the middle East and Asia, but have become extinct, only the sub-Saharan African species remaining today. Almost all the living long-faced antelopes consist of species-complexes, where different populations can be considered subspecies or sometimes even full species. Figuring out their classification is an ongoing puzzle for zoologists. These different groups have evolved quite recently and indeed evolution in the long-faced antelopes is ongoing. The different subspecies might be seen as representing a burst of speciation; the ones that survive might soon become fully fledged species. An important factor in this speciation has been climate change associated with the Ice Ages. While there never was much ice in Africa, there were nevertheless fluctuations in rainfall causing periodic spreads and retreats of forests, savannahs, grasslands and deserts. Hartebeests prefer grasslands, and if regions of grassland became separated by intrusions of forest, animals in the two separate regions would have evolved independently and come to differ from each other. If grasslands dried out to semi-desert or desert, without more suitable habitat being available nearby, the hartebeests might have adapted to the drier climate. When the climate changed too much extinction might have resulted, and many extinct long-faced antelopes are indeed known from Africa and Asia, but if the changes are gradual enough, adaptation can be successful, and the many different forms that exist today prove that hartebeests are good at adapting and surviving.

I’d like to say something here about the concept of ‘survival of the fittest’. Charles Darwin coined the phrase and his idea of ‘fitness’ was not what today we think of in terms of ‘fit’ humans, but instead meant ‘well adapted to the environment and able to meet all likely challenges’. Darwin saw this as the driver behind speciation: ‘unfit’ members would be more likely to die and less likely to reproduce, so that the ‘fit’ members would predominate … what he called ‘natural selection’. He saw changes as being very gradual, and so, as the environment gradually changes, the species in them would gradually change as well.

Today it would seem the real picture is more complex. Now the next bit is my personal view and I’m not sure just how well substantiated it is, but I think evolution happens more because of a ‘drifting’ in features that have little impact on survival. The drift might be slow and gradual, but more rapid and drastic changes are also possible. So: two populations of hartebeests become separated from each other. As time goes by there is a kind of ‘drifting’ of features … in the one group the horns become taller and more narrowly-set, and in the other group the horns become wider and more spread-out. These aspects have little impact on survival. What causes one group to have the one kind of horn and the other to have a different kind may have nothing to do with adapting to the environment; instead, bulls in one group may develop a preference for a different style of fighting than bulls in the other group, or maybe the cows in the one group develop a preference for bulls with a certain kind of horns. Or maybe something else. But at any rate what does seem to be true is that populations of animals are never static, they don’t remain the same; over large expanses of time they will fluctuate and these fluctuations will cause a kind of slow change in features irrespective of other factors.

Then as I said there is also the possibility that some changes may happen in bigger ‘jumps’, a view sometimes called saltation. This is because the genes of animals don’t just specify specific small features; there are genes that are responsible for collections of features or for entire patterns of growth and development. A single change in such a gene could therefore result in a drastic change in an entire organism. Evolution by this means would happen much more rarely, since such a drastic change is more likely to quite mess up an animal – what we would call a harmful mutation than to leave it functional. But this can happen, and over very long spans of time I am sure it does happen. Also such mutations might be more benign when they affect structures not immediately necessary for survival. A higher-order mutation in a hartebeest population might for example be responsible for a striking difference in horn shape, which might become established in a small population within a few generations. An attraction to novelty has been demonstrated in some species: males that have striking novel features are favoured by females irrespective of whether these features are beneficial or not. I hypothesize this is a general truth for many species, and on its own might help novel mutations to become established and so drive evolution.

So, natural selection is not what drives the change; it is just the shears that prunes away the ‘sick’, that is to say maladaptive and dysfunctional, branches of the tree of life. What drives the change is the natural tendency to vary and to fluctuate, a kind of adventurousness that is intrinsic to life. To boldly go … that is what life is, it reaches out, it goes everywhere it can, it does everything it can, and then tries for even more than that. Life strives for novelty, life will test the limits of what it can get away with. And life out there is actually quite forgiving; most environment will have very wide parameters within which species inhabiting it can fall and still survive. When we look at species modern or ancient, what we see is not exactly fine-tuned machines perfectly able to survive; instead we see species with a bewildering variety of weird features with bizarre or even incomprehensible uses, and often we are amazed that they manage to survive at all. But that is because life is not as harsh as it is often made out to be; there is leeway for experimenting and trying out strange stuff. Much of the strange stuff might later turn out to have benefits for survival, or might turn out to open up new possibilities for revolutionary future developments … or not. But so long as they don’t actually cause catastrophic harm, they’re allowed. Nature is in fact very permissive. And this is good … for us and for everything else. But every several million years or so times do become hard, and that is when mass extinctions happen, and then only the fittest survive. The tree gets pruned heavily, but afterwards fresh new growth sprouts out again.

Back to our subject! In the wild you will usually see red hartebeests from a distance. They are very wary, especially in regions where they are hunted. They will typically stand with their bodies side-on but with their heads turned right towards you. During the hottest time of the day they might rest in the shade of bushes and trees, sometimes sitting or lying down. They can be surprisingly inconspicuous then, but they remain on the alert. Hartebeest eyes are set at the sides of their heads, and this together with their wide pupils give them a very large field of view: they can see what’s in front of them, what’s to the side of them and even a bit of what’s behind them, all at once. Their large nostrils indicate they have a good sense of smell as well, and their small ears will prick as they listen for suspicious sounds. At any sign of danger they will gallop away with a rather stiff-legged gait. They can reach 80 km/h, 50 mph. They will fight a predator if cornered. With their powerful necks they can wield their sharp horns with deadly force. Hartebeest cows will defend their calves with great ferocity.

But hartebeest bulls mainly use their horns for fighting with each other. Fighting is usually a last resort, being preceded by intimidating displays. Most people will say they are ‘kneeling’ while they fight but actually they drop down on what in us humans are the wrists. Then they lock horns and wrestle each other. A victorious bull might force his opponent’s head sideways and manage to stab him in the neck, sometimes even killing him. Females sometimes fight each other too.

But these antelopes are also cooperative. In a herd there will always be at least one member on the lookout for danger while the others graze. Hartebeests will take advantage of the climate, moving around from one region to another to follow the rains and the growth of fresh grass. On this abundant food source they grow quickly, young hartebeests reaching sexual maturity at the age of two years. They can live for up to twenty years in the wild.

Colours of Wildlife Archive

Willem

25.02.13 Front Page

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