Mhudi
Page 9
A highly respected ecologist was recently commissioned to compile an independent ecological management plan for one of the regions in Balule. His waterhole strategy was, in my opinion, a tad on the radical side. He recommended that water points in the lowveld should be placed at 30-kilometre intervals. Try to visualise the whole area from the railway gate in the south to the Olifants train bridge in the north without any waterholes. The only water available would be the Olifants River itself. The hardest to swallow was that the region that commissioned this report was only 3 200 hectares in extent. You would need a reserve area of at least ten times that size to qualify, as per his recommendation, for even one water point!
Before man’s manipulation of the lowveld, the Olifants River was nature’s winter waterhole in our area for hundreds or thousands of years, so why not take advantage of this and emulate nature, as was being suggested by the respected consultant ecologist? Realistically speaking, given that Adam and Eve ‘have left the building’ and the system is no longer pristine, implementing this radical policy would require massive sacrifices and a rather strong stomach.
Imagine the carnage on the railway line with herds of game crossing twice each day to and from water. Eventually, fences would need to be re-erected just to keep the game off the tracks. Those animals utilising the riverine area would soon denude all the available vegetation in the proximity of the river and they would then be forced to move back across the railway line to feed. Elephant would concentrate on the trees and shrubs on the river in winter, no problem with that, it’s perfectly natural. But, then, so is the ever-increasing wasteland of Chobe!
In ten years’ time, given the rate of increase in the elephant numbers on the reserve, this would eventually result in the only prominent features on the Olifants River flood plain being shareholders’ lodges and the odd leadwood tree. Due to the lack of vegetation, game would move away en masse for months at a time, much as they did hundreds of years ago, only this time they would encounter national highways, fences, farmland and other unnatural barriers. Then and there, they would die attempting to cross them, or end up piled against the fence, like the eland and wildebeest did in their thousands when the Kuki fence was erected in Botswana.
The veterinary fence that was erected on the Kruger National Park’s western boundary in the 1960s also took its toll, accounting for thousands of dead animals, mainly wildebeest. Before the removal of the fence between the Kalahari National Park and Botswana’s Central Kalahari, thousands of animals perished trying to migrate in search of water. So, despite the huge conservation drive to remove fences and create Transfrontier Parks, there are still many thousands of kilometres of these barriers still in existence.
If we give due consideration and logical thought to the conditions necessary for adopting an ‘au naturel’ approach, it becomes increasingly apparent that we must be realistic about a possible reduction in or even closure of waterholes on our reserve. Which waterhole? When? For how long? All questions and all undoubtedly wildly varying answers will need to be carefully considered. Also, I believe that the modern approach to water provision on privately owned land needs to be tempered with moderation, which, until we know the answers, would be preferable to a radical approach either way.
The management of a private reserve requires the maintenance of an interdependent balance between the ecological well-being of the reserve and the enjoyment of the members/owners. Without this symbiosis, neither will be happy and as in any healthy longer-term relationship, there needs to be a certain degree of compromise and sacrifice. ‘Appropriate’ and ‘adaptable’ are another two words that come to mind.
Until we have specific and researched answers to all aspects of the waterhole issue, we can, in my opinion, distribute our water points at an optimum spread of one per 1 000 hectares. Each waterhole needs to be large enough to water at least 100 LSU (Large Stock Units) at a time, with bird baths and conventional cattle troughs not featuring in the equation at all. This use of LSU as a statistical measure will be examined further in later chapters.
With specific reference to the larger open system’s private nature reserves, the following are three leading ecologists’ viewpoints which may be taken as unofficial waterhole management/distribution guidelines. What I find particularly interesting is that despite nearly 30 years separating one of these reports, the recommendations are pretty much six of one and half a dozen of the other.
A management report submitted 30 years ago for the Sabi Sand Game Reserve recommended, as a rule of thumb, that water points not be closer than three to four kilometres to one another, and one water point to serve an area of between 900 and 1 600 hectares. The Balule management plan compiled by the Agricultural Research Council (ARC) stipulates that a distance of three kilometres between waterholes be regarded as an absolute minimum. An unofficial guesstimate for an area such as the Timbavati is one water point per thousand hectares. This opinion was given by a well-respected ecologist at a meeting with landowners of Timbavati, where they met to discuss this very issue. Currently Olifants has seven water points that almost fit the criteria as recommended and they are spread quite evenly over the area. At this stage we are pretty close, with one per 900 hectares. But … Shhhhh! Don’t mention the river.
I have long held the belief that the even distribution of ample water points in a closed system is the more logical management option; in other words, saturation as opposed to isolation. This has tended to be a safe position to hold for fear of being branded a conservation Neanderthal and being relegated to their beetle-browed dead-end branch on the tree of evolution. Happily, and without scientific backing, I am now ‘coming out’ on this issue. There is now overwhelming evidence to suggest that one of the prime factors contributing to ideal conditions for the spread of disease amongst wildlife populations, is exacerbated by unnaturally concentrating animals in a small area, and that is exactly what isolated waterholes do. They also concentrate larger numbers of game when they’re at their most vulnerable physically, when their resistance is lowest, namely in the winter months. Therefore it is no coincidence that we find the majority of anthrax cases manifesting in the dry months. Conversely, when the rains arrive and there is an abundance of surface water, the game spreads out, their physical condition improves and the disease disappears.
Evenly spreading a population over a number of waterholes means that the concentration of faeces, urine and saliva is relatively diluted. This also minimises the spread of other parasites which may further contribute to animals’ already poor condition, due to lowered nutritional levels of the winter vegetation. Fewer hooves stirring up the surrounding soil in which the anthrax resides, means less airborne spores, thereby reducing the risk of infection through inhalation.
Besides the obvious influence that water distribution has on the spread of diseases, the saturation theory has other merits worthy of consideration. I believe that an area saturated with well-planned and evenly distributed water points is a better veld management technique in a closed system, than the rotational grazing method. In my opinion the latter practice is better suited to animal husbandry. This technique isolates the water points, forcing game to concentrate on a particular area, which can have long-term detrimental effects, with possibly irreversible damage.
The basis of the saturation theory is that animals won’t travel any further than they have to, to obtain water. An even distribution of water points should therefore result in an even distribution of animals. This even spread of game then applies an even amount of pressure over a larger area.
Spreading a given biomass, or number of animals, over a large area should reduce the damaging effect that the same biomass would have had if it was concentrated on a smaller area. This all presupposes, of course, the all-important qualification – that the biomass does not exceed the carrying capacity of the total area. This is critical to the whole concept of saturation.
Evenly spreading a number of waterholes over a given area will reduce the distance an an
imal has to move to obtain water, therefore it expends less energy. By reducing its energy requirements, the animal utilises proportionately less fuel and maintains better physical condition over a longer period of time, given the same energy intake. This further reduces demand on the veld.
In large game reserves that have isolated waterholes, like Etosha Pan, for example, the wagon wheel effect is clear to see. This feature is made up of well-worn game paths, caused by the relentless hooves of thousands of animals travelling great distances, focusing into the waterhole and then radiating out again. These paths can develop into dongas on sloping areas, resulting in serious soil erosion. Most of the larger reserves are able to absorb this level of utilisation and resulting consequences, but smaller closed systems cannot sustain this pattern of usage.
The key issue to which I alluded is, then, not so much waterhole management as it is animal biomass management. And, ‘that’s my report and I’m sticking to it!’
Controlled water points are a definitive management tool if used wisely, but I suspect, as with fire management, the tendency is to overdo things a little because the short-term results can be quite spectacular. Before-and-after photos produce dramatic evidence and speak volumes in a presentation portfolio, but I am of the opinion that the long-term effects of an intensive regular burning programme may negatively affect the animal species diversity. This observation applies for the most part to invertebrates, small mammals, reptiles and birds, and to a lesser degree the vegetation, particularly the woody component.
‘Locores’ meetings are always interesting and varied. In essence they are informal gatherings of ecologists, local landowners and managers to discuss issues of common interest relating to conservation. The venue for the meeting to which I am now drawing your attention was a successful rare antelope breeder’s game farm, which specialises in roan, sable and tsessebe antelope. Nearly all this farmer’s emphasis is placed on managing the farm’s vegetation with these antelope and their specific needs in mind. Besides an extensive ongoing bush-clearing programme, it requires a burning regime that would be far too radical to apply in an open system such as ours. It was, nevertheless, an absolute model of a farm in terms of grass production. I have to admit to being really envious because, relatively speaking, Olifants was sparsely covered, and our grass species composition is rather shy on perennials. Anyhow, I wasn’t really comparing apples with apples, so back to the point, which is to do with one of the effects of fire, or rather, too much fire.
We took a short break at midday, lolling around in their lush grass which appeared to have largish patches of bare earth between the tussocks. There was virtually no dead material, old grass, leaves or that sort of stuff, and what struck me as strange to the point of being disturbing was the lack of insects or signs of insects. When you stuck your face down at creepy crawly level, it was quiet and sterile. That’s what worried me then, as it still does now.
Before the pyromaniacs amongst you advocate regular burning, as man has had a positive influence on the creation and maintenance of savanna habitat by doing just that, we need to remember that the use of fire by man is a relatively modern discovery. In terms of man’s intentional influence on the ecology, it is a recently discovered management tool. Unconscious of the ecological ramifications, and with only survival in mind, primitive man used fire to make hunting easier for himself, inadvertently creating conditions that favoured grassland rather than woodland. Later, this practice was applied in similar fashion to provide green pasture for his domesticated animals.
Unfortunately we have no reliable records to tell us what the area looked like before this regular manipulation by man and his fires. Nor do we have accurate data on the frequency of natural fires at that time. In all probability, these fires would have been irregular and burned in natural mosaic patterns, following seep lines, river courses and ridges. I believe this would be preferable to neatly cut fire breaks, which facilitate neatly burned blocks and covering tightly defined areas as prescribed by modern fire management techniques. Almost always, these are burned along property boundaries irrespective of what diverse ecosystems the fence or break traverses. This can’t be good.
In all fairness, fires are classified in terms of their intensity and alternating the intensity and frequency of a burn is fundamental to fire management. So you will hear of the use of a hot burn, a cold burn or even a wet burn in terms of achieving the desired results. Well, desired by their practitioners, that is.
These questions must have raised enough concern to cause scientists to revisit burning policies in the National Parks. Kruger National Park’s fire ecologists have been experimenting with allowing natural fires to burn themselves out. Although some of these fires do tend to cover large areas, they’re at least following natural firebreak lines dictated by the characteristics of the terrain. The infrequency of these fires will allow the natural cycles of some organisms to complete the process necessary for survival that otherwise may have been interrupted or destroyed by regular fires initiated under a rigorous fire management programme.
Observations During Drought
October 2008
October is often referred to as ‘suicide month’ in the South African bush and it’s not difficult to see why. I refer to IR Tannehill, an American meteorologist, who wrote, ‘Drought is unique among spells of weather, it creeps upon us gradually, almost mysteriously, but its consequences are a terrible reality. Drought is one of the best examples of our helplessness before the broad-scale phenomena of nature.’ Although this was written more than 60 years ago, it could have been written yesterday.
Having lived through a few severe droughts in my time doesn’t make it any easier to accept the present state of affairs. It remains difficult to imagine that this relentless drought will break, that the test will soon be over, and the prevailing hazy grey landscape will change dramatically. In a matter of days following the first good rains, the bush will transform itself from what once resembled a worn-out old witch’s broom to lush green growth, vibrant with the promise of life. This process of extreme desiccation followed by good rainfall is essentially an ecological necessity in this environment and contributes in its own way to what makes Olifants the sought-after slice of paradise it is. Knowing this helps us get through this depressing phase and keeps many of us confidently optimistic.
Olifants Game Reserve is blessed with an abundance of big game, but often in the scramble to chalk up the Big Five, the smaller animals don’t get the attention they deserve, in particular the smaller antelope species, of which we have four, namely the klipspringer, the common duiker, Sharpe’s grysbok and the steenbok. I have never seen a red duiker here and strongly suspect that the ‘red duiker’ that gave the drive to Grootdraai its name was a quick glimpse of a young bushbuck doe. So I am sticking to four until proven otherwise.
The prevailing drought has resulted in extremely sparse vegetation, which has now exposed the smaller, normally more easily concealed antelope mentioned above. These little guys don’t hang around long, which can make positive identification difficult. Knowing a little about the habitat type each prefers, however, will at least narrow down the possibilities somewhat. Let’s deal with the most confusing of these, namely Sharpe’s grysbok and the steenbok.
The similarities in their appearance are confusing. Both are a light rusty red, weigh approximately the same and in both species, only the male carries small pointed horns. How then do you tell them apart, when all you get most of the time is a quick glimpse? The most reliable rule of thumb clue lies in habitat association. Each of these two antelope occupies a specialised niche in the environment. So specific are their respective requirements that their home ranges hardly, if ever, overlap. To this end, it would be safe to bet that if a small reddish antelope is seen in the hilly, rocky terrain of Grootdraai, ten-to-one, it’s a Sharpe’s grysbok. Olifants North, similarly, would have more Sharpe’s grysbok than steenbok.
A little red antelope seen in the sandy open country on
the east of the old main access road would, ten-to-one, be a steenbok, and if you see a little red antelope drinking water, hundred-to-one it would NOT be a steenbok. Later, as you get good at this and manage to get your binoculars trained on them, you will also notice that the grysbok has marginally shorter legs and white flecks in its fur, as if it had been lightly dusted with coconut icing.
Drought conditions, and the subsequent response to resource stress, bring out the survival instincts in all wild animals. How each adapts and copes is key to their survival. As an example of this, let us focus on the often-overlooked steenbok. These little antelope are completely at home in an arid environment and besides the common duiker are probably the most widespread antelope species in Southern Africa. In the Kalahari Desert they draw all their water requirements from the vegetation they eat and those we come across on Olifants rarely utilise waterholes. I have never seen a steenbok drinking water in the 35 years I’ve been in the bush.
Knowing this, I was intrigued to find a pair of steenbok at Hide Dam. Eventually, after frequent sightings, I began to wonder if, due to the prevailing drought, all the available vegetation was so dry that even they needed to supplement their moisture intake.
Closer observation, however, revealed that they were eating a water herb Ludwigia stolonifera that was growing in the shallow water at the edge of the dam. In Elsa Pooley’s Wild Flowers of KwaZulu Natal, she states that this plant is visited by ants. I’d love her to see what other species also ‘visit’ this plant in severe drought conditions! The water level of this dam is maintained by pumping water from the Olifants River by means of a four-kilometre underground pipeline and the pump mechanism employed would prohibit even the smallest seed from slipping past the tight fitting rotor and stator. I suspect, therefore, the seeds of this plant were ‘flown in’, more than likely on the legs of the wading birds that this body of water attracts.