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!"

Today I have for you one of South Africa’s most magnificent antelopes – the Gemsbok, Oryx gazella! The name has nothing to do with its jewel-like beauty. ‘Gems’ is Afrikaans (via Dutch) for the Eurasian mountain goat the Chamois, Rupicapra rupicapra. Why this huge antelope of the sand dunes reminded the Dutch colonists of a lightly-built Chamois living in the Alps, I have no idea! The scientific name is interesting also; this species is also known as the Southern Oryx. It is not a gazelle at all! Gazelles are small, graceful antelopes, while oryxes are on the large side. But they all live mainly in deserts and other open habitats. There are four living species of oryx, the others being the Beisa Oryx of northeast Africa, the Scimitar-horned Oryx that used to live in the Sahara Desert – now sadly extinct in the wild but still present in captivity – and the Arabian or White Oryx, which also almost went extinct, but is now benefiting from active conservation projects.

I also feature today a painting by my father, Peet van der Merwe, showing three Gemsboks on a desert dune. The single gemsbok drinking water is by me!

The Gemsbok’s distribution is centred around the Kalahari Desert of South Africa, Botswana and Namibia. This is not a true desert, but a dry savannah with sparse grass and trees growing on deep sand. Because rain sinks down into the sand as soon as it falls, there is hardly any surface water available, and the only rivers are in the far north and south, leaving an immense dry region in between. Rainfall is very unpredictable; there can be years where it hardly rains at all, and then every several years there are abundant rains that fall in a few, massive thundershowers. This ‘desert’ hosts surprising amounts of large mammals; it is one of the last great wild regions remaining in Africa, its harshness having kept most humans out. There are still a few of the San people or Bushmen living in the Kalahari and sticking to an almost-traditional lifestyle.

The Gemsbok is one of the most drought-tolerant of the antelopes. It has a slow and adaptable metabolism, and it actually burns fewer calories during normal activity than most other antelopes. Behaviourally, it is up and about during the cool morning and afternoon hours, spending the hottest part of the day resting up, in the shade of a large tree such as a camel thorn if that’s available. If there is no shade, as often happens in the desert, it will turn its body so as to present the least amount of surface area to the sun. It also helps that its coat is mostly light in colour, reflecting most of the intense sunrays. It will often scoop out a hollow in the sand for itself to rest in. It has a system of branching blood vessels in its nose; blood circulates through these while a gemsbok breathes, and moisture evaporating from them cools the blood on its way to the brain, thus guarding this most vital organ. Because the brain is safe, a gemsbok can allow its body temperature to rise a few degrees above normal without ill effect, shedding the heat again during the cool evenings and nights. They can tolerate overheating for a few hours before having to start increasing heat loss through evaporation, which they accomplish by panting rather than by sweating. At other times they breathe very slowly to minimize water loss.

A gemsbok also has broad hooves that give it good traction on the loose Kalahari sands. The bold black markings on its face and body are visible from a great distance. The males, standing on the top of sand dunes, are therefore able to advertise their ownership of the large territories they need for finding enough food. During years of abundant food they’ll put on fat stored beneath their skin, which they can feed on during times of shortage. Gemsbok are grazers, but will eat anything that’s available, eating leaves of trees and shrubs or herbs if necessary. Especially valuable to them are the large, juicy, melon-like fruits of the Tsammas, Naras and Gemsbok Cucumbers (all three these species are members of the Pumpkin family). They also dig up tubers: there are many tuberous plants in the desert. During rains they absorb the water from the soil and store them in the deep tubers that won’t rapidly dry out. Some of the tubers of the Kalahari can grow incredibly huge, but are also often very deep underground. The gemsbok use their big hooves for digging. They will also dig in the beds of rivers and the many very short-lived streams that flow after heavy rains; in this way they can access the precious subterranean water. But if they can’t get at any subsurface water, they can still survive for very long just from the moisture they get from the plants they eat. But they very much appreciate access to drinking water. Gemsbok bulls will even fight for it!

Fighting in fact seems to be in the blood of these antelopes. Both the bulls and the cows sport the very long and sharp, straight horns. These are like spears and used to similar effect! There are lions, hyenas and leopards in the Kalahari, but a single gemsbok can certainly finish off one of these. You can see from the depth and thickness of a gemsbok’s neck that it has the strength to wield these more-than-a-yard-long spears with deadly force. Interestingly, the horns of the male tend to be shorter than those of the female, but thicker. Female gemsbok can have horns that slightly curve backward, while those of the males are ramrod-straight.

But gemsboks also fight against each other. Bulls and cows defend territories, those of the bulls being smaller. That is because bulls occupy single territories, while cows group into herds that graze over large ranges. Gemsboks are fairly sedentary, sticking to a certain patch year-round rather than moving around a lot like some other desert species. Some males are non-territorial and will join the female herds. The territories may be abandoned during especially dry years, the animals moving out in search of food, willing to face the risk of conflict over starvation. Fighting between gemsboks is mostly ritualized sparring, during which they will test one another’s strength but try to refrain from actually inflicting injuries. Still, injuries and deaths do occasionally happen. To protect them against each other, gemsboks have very thick, tough skin enveloping their necks and shoulders.

But part of the gemsbok’s energy-saving strategies is to minimize actual fighting. They therefore try to settle disputes as much as possible by displays. Here their bold markings are used to good effect. Just standing motionless on a high dune already shows other gemsbok that you are there and that the territory is yours. Other signs of a region being occupied are the hollows in which the gemsbok rests, and the neatly deposited piles of dung. Scent is also a factor in the dung piles and in scrapes, since gemsboks have scent glands on their feet. Two gemsboks that actually meet and dispute a territory will use displays in which they raise and lower their heads showing off their horns; circling each other, walking parallel to each other, and lightly head-butting each other. Most of the time it goes no farther than this. The gemsbok who decides his opponent is too much for him will bow his head, or lift his chin, or crawl towards the other one on bent legs.

For these hardy antelopes, breeding can happen any time in the year. The cow carries the calf for nine months. At birth it is a rusty brown colour that helps it blend in with the reddish desert sand. For the first month or two it will hide itself by lying flat while its mother goes out to feed before returning to nurse it. The calves reach adulthood at the age of two years, and female calves stay with their mother’s herd for a year or so, while the young bulls move out. In the wild a gemsbok can live for twenty years.

Although the gemsbok today still occurs over a very large area, its range has contracted somewhat. Previously it was found further in the south, in the Karoo region of South Africa. It has been eliminated here and in a few other regions by hunting and because of pressure from sheep and cattle farmers. Apart from the Kalahari itself, it also occurs in the Namib Desert of Namibia and Angola, which is indeed a true and very harsh desert, as well as in some other dry woodland regions of Namibia and into southern Angola. It is present in many game and nature reserves, and also on game farms.

Colours of Wildlife Archive

Willem

16.12.13 Front Page

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