Kruger National Park New Elephant Management Plan
In 1995, following pressure from animal rights groups, The South African National Parks Board agreed to stop elephant culling in Kruger National Park and to review its elephant management strategy. The last elephant culling exercise of the 20th Century in Kruger, therefore, took place in 1994.
The suspended elephant management programme was initiated in 1967. Its objective was to maintain the game reserve’s elephant population at 7 000 by culling the population’s annual increment every year. Seven thousand was then thought to be the maximum number of elephants the game reserve could sustainably support.
Since 1995 there has been a huge amount of scientific thought given to formulating a new elephant management plan. Nevertheless, two years into the new millennium, it is still not complete. In the meantime, Kruger’s elephants have increased without control. I have calculated that, increasing at a rate of 6.8 percent per annum – which is the known incremental rate - the Kruger elephant population will reach 11 850 animals this year.
The new plan proposes that the park be divided into six blocks for management purposes.
There will be two small botanical reserves, one in the extreme north and another in the southwest. These areas contain plant communities that are deemed important enough to be afforded very special protection. Elephants, therefore, will be allowed to live in these areas only in very low numbers.
The rest of the park will be divided into four near-equal-sized blocks. This means they will each be approximately 5000 square kilometres (c. 2000 square miles) in extent. Each block will be managed separately according to the assessed impact that the elephants have on the vegetation.
The success of the new plan is dependent upon individual elephants not wandering all over the park but remaining wedded to their home ranges. The fact that adult Kruger elephants have shown great fidelity to their home ranges was confirmed by the results of the satellite tracking of many radio-collared elephants over several years. Furthermore, it is known that it takes some significant disturbance to make an elephant leave its established home range and to seek a new place to live elsewhere.
The objective of the new plan is to force variably changeable vegetation growth cycles in each block as a consequence of manipulated elephant impacts on their habitats – but only up to certain upper and lower limits of acceptable change. The rationale behind this strategy is that certain plant and animal species are known to thrive on degrading habitats whilst others prosper on recovering habitats; and that these same species merely exist in stable environments. Concomitant with this idea is the thought that the ecosystem will operate more dynamically in a hugely fluctuating environment. The proposed new management plan, therefore, will create conditions that will allow the almost complete spectrum of all possible ecological circumstances to come into operation in all corners of the park - over time - and that the man-manipulated vegetation-growth-cycle fluctuations will be repeated again and again over time, too.
The previous management strategy, by comparison, tried to maintain a stable elephant population in an unchanging habitat. This did not altogether work. We know this because, throughout the culling era, progressive habitat degradation is known to have occurred. It failed, therefore, because the park was carrying too many elephants.
A study conducted in the Satara area of the park in 1944 showed that the average number of mature top canopy trees was then 13 per hectare (2.4 acres). As there were no elephants in the Satara area at that time we can presume that 13 trees per hectare represents the probable climax-state of the woodland in that region of the park.
All vegetation communities constantly strive to reach their maximum possible state of growth. When this is achieved we say the vegetation has reached its climax state. This represents, therefore, what we might call its 100 percent growth potential. When animals reduce the climax state byfeeding on the vegetation, and/or when animals break it down as elephants do, we say that it has been reduced to a sub-climax state. The various degrees of sub-climax can be measured as percentage units of the 100 percent climax maximum. And, as the most important and the most obvious component of a woodland or forest complex is the number of top canopy trees present, top canopy trees represent the most measurable raw factor of important changes that take place in the climax states of woodlands and forests.
The first group of elephants took up permanent residence in the Satara region of Kruger in about 1960 – following visitations by pilot bulls a few years previously. For some six or seven years the new residents did not exceed 300 - 400 animals. Nevertheless, by 1965 these few elephants had reduced the number of top canopy trees to 9 per hectare.
The Satara elephants then started to increase but when culling commenced in 1967, the population stabilised. Nevertheless, by 1974 the tree population had been reduced to 3 per hectare, and by 1981 it was down to 1,5. This information, alone, tells me that 7000 elephants is far too high a number for Kruger to carry. An elephant population that does this kind of progressive damage to top canopy trees is NOT sustainable.
I have no information regarding what the mature tree population in the Satara area is now. The numbers of elephants, however, was clearly excessive throughout the culling era (1967 - 1994) and since culling ceased in 1994, there has been a 69 percent increase in Kruger’s overall elephant numbers, to date. I must conclude, therefore, that the damage to top canopy trees at Satara has become progressively worse every year since the last assessment was made in 1981.
The new elephant management programme envisages that elephant populations in the two central management blocks will, initially, be allowed to increase in number without constraint. This means they will be allowed to devastate their habitats. In the northern and southern management sectors, on the other hand, the elephant populations will be reduced in number at a prescribed rate - by annual culling. The management objective in this case will be to allow previously damaged habitats to start growing back towards their climax.
When certain defined upper and/or lower thresholds-of-change have been reached in any one block, the management strategy for that block will be reversed. This means that, in each case, the elephant populations which had been allowed to proliferate uncontrollably, will be reduced in number; and that the elephant populations that had been reduced in number will be permitted to expand.
The merit of the new Kruger elephant management plan rests on the assumption that when elephant numbers fluctuate around what we might call an ecologically optimum population density, biological diversity benefits. The trouble is we don’t yet know what the optimum elephant population density is for Kruger. The new management plan will get round this problem, however, by causing the elephant populations, in all four management blocks, to constantly fluctuate between prescribed high and prescribed low extremes - through this magic density number - upwards and downwards, over time, and all the time.
This new idea is a departure from the old insofar as the previous management objective was primarily elephant-centred. Nevertheless, preventing species loss was a major management objective, too. And no species were lost because the slow deterioration of the habitats has not yet – even now - reached its logical conclusion.
The new management plan, by contrast, is species-diversity-orientated. This makes infinitely more sense because our big game national parks were created, primarily, to maintain the nation’s biological diversity. They were NOT set aside as purely elephant sanctuaries!
The limits of environmental change that are going to be permitted in the new plan - which will include radical habitat changes - have been termed ‘Thresholds of Potential Concerns’ or TPCs.
The parameters for these TPCs are currently being worked out. And it is because they have not yet been fully determined – so I have been told - that the new Kruger elephant management plan has not yet been put into operation. The TPCs are complicated and they take into account a multitude of biological and botanical realities. One of the more simple-to-understand upper TPC’s, for example, is going to be a permissible maximum level to which the numbers of top canopy trees will be reduced – which the scientists know will happen when the elephant populations are expanding. One of the lower TPC’s is going to be the extent to which regenerating woody scrub vegetation is going to be allowed to invade the grasslands (bush encroachment) – which is expected to happen when elephant populations are forced to decline. And, in between, there is going to be a range of other measurable phenomena, such as changes that occur to the strengths or weaknesses of certain ‘indicator’ bird species populations that are known to vary – upwards AND downwards - with trends in habitat change.
The commutations are likely to get very complicated and capricious biomass changes in other large herbivore species are likely to seriously affect predictions. For example, as the elephant populations decline in the actively managed blocks so macro-grazing species such as buffalo, wildebeest, zebra and white rhinos are likely to increase – and they may substantially alter the course of events in the prediction models in one direction. Changes in the biomass of the browsers – such as eland, kudu and impala - on the other hand, will likely change the models in another direction. Fire could play a major role, too. And all the time the constantly changing circumstances within this hugely dynamic state of affairs will have to be very carefully and constantly monitored.
I am particularly concerned about how the TPC’s are going to be determined for top canopy tree removals because top canopy trees are fundamentally so very important to a whole range of plant and animal communities. I understand the figure of 80 percent is being mooted as the upper TPC for this aspect of the planned programme. In this regard there are two considerations that worry me.
My first worry concerns what happens when the 80 percent level of top canopy tree destruction is reached. It will not simply stop at that level even IF the elephant population is suddenly and drastically reduced in number. Even by half! In other words, there will be a carry-over of tree destruction beyond the 80 percent TPC. And there will be no replacement trees coming through until the elephants are so reduced in number that regenerating tree saplings are able to ‘get away’ from the annually declining number of elephants – which will, without doubt, take many, many years. This, I understand, is one of the vexing questions with which the scientists are now wrestling and which is causing the delay in implementing the new plan.
My second worry concerns how the baseline parameter for this important TPC is going to be determined. On what 100 percent figure, for example, will the Kruger scientists base their permissible 80 percent top canopy tree destruction TPC limit?
In this regard, I must point out that, in the Satara study, elephants reduced the climax top canopy tree population by a staggering 89.5 percent between 1960 and 1981 - a period of just 21 years! And that this trend must have advanced even more during the next 21 years - which brings us up to the present time. Finally, I believe various degrees of similar top canopy tree destruction must have occurred all over Kruger National Park as the game reserve’s pioneer elephant population expanded into all the many corners of the park. I believe, therefore, that my concerns are valid!
In the new Kruger elephant management model it has already been decided that the northern and southern elephant management blocks will initially have their elephant populations reduced at the same rate at which they are now expanding. This will entail reducing each year’s standing population by 14 percent. The first 7 percent will take off the annual increment. The second 7 percent will represent the reduction. The number making up the 14 percent, therefore, will get smaller and smaller as the population size diminishes by 7 percent each year.
In those populations that are being culled, therefore, the population will be halved – and halved again repeatedly - every ten years. And in those populations that are not subjected to culling, the populations will double their numbers every ten years. Ironically, the new elephant management plan for Kruger National Park – although it came about because of animal rights objections to the culling of elephants - will probably end up killing more elephants every year than was the case before.
In my opinion, far too many assumptions have been made in support of the proposed new Kruger elephant management plan. There are also far too many probable and unpredictable natural intrusions that are likely to interfere with management predictions.
I have particular grave concerns, for example, regarding the hundreds of years of time it will take to replace many of the sometimes enormous and ancient riverine-forest hardwood trees that the elephants will remove during each and every elephant high-population cycle. I must also cite my concerns for the giant and unique baobab that is one of the first trees to be eliminated when elephant populations exceed the carrying capacity of their habitats. And baobabs, most authorities agree, reach an age of at least 2000 years. Some even support an improbable age of 5000 years! The man-manipulated cycles envisaged in the new plan cannot possibly have taken these kinds of time-scales into proper account.
What can be said of the new elephant management plan is that it is ambitious. I also – with respect - believe it to be scientifically pendantic in the extreme. And I have no idea at all why THIS elephant management plan should have been adopted given the nature of the animal rights challenge that brought it into being.
Furthermore, I believe that there will be great risks in its implementation. There will be risks with regard to unnecessary topsoil losses. There will be risks to the long-term health and vigour of plant communities – including risks of plant species losses. And there will be risks to the health and vigour of animal populations – including risks of animal species losses, too.
Against this risk factor must be weighed the fact that the game reserve’s previous elephant management plan experienced NO species losses at all – despite its deficiencies. In my humble opinion, therefore, it will be much more beneficial – even now - for the sake of Kruger’s species diversity, if the game reserve’s elephant population was to be simply reduced to 4 000 or 5 000 animals; and stabilised at that kind of level.
Nevertheless, I consider the new elephant management plan for Kruger National Park to be a sophisticated and serious experiment based upon sound scientific ideals. It is, however, one that is fraught with far too many uncertainties, and far to many important and unacceptable risks. I will not be surprised, therefore, if it is abandoned before it is even implemented. Conversely, if it is implemented, I will not be surprised if an altogether new elephant management plan, that has more realistic and more attainable objectives, will soon replace it. What I am quite sure of is this: IF elephant population reduction is not implemented – soon - irreparable damage will be inflicted upon the ecosystems of Kruger National Park and species of plants and animals will start to disappear.
I shall, therefor, watch the development of this extravagant experiment with very great interest – and with some degree of consternation, too - as what is left of my life ebbs away into eternity.