According to research by SANParks, elephants have reduced the numbers of top canopy trees in the Kruger National Park by more than 95% since 1960, and this figure increases annually. But the scientists who are now dictating the elephant management programme in the Kruger argue that the perception this statement projects is false. They say that the situation is far more complex.
They are right, of course, but there can be little doubt that the park’s excessive elephant population over the last 50 or so years has been the primary cause of top canopy tree destruction, and the current ‘non-intervention’ (no culling) management programme is seriously exacerbating the problem. The five scientists responsible for the ‘non-intervention’ policy state: “Society must ultimately judge the balance between local disappearance of some rare plants or the loss of a more substantial component of ecosystem diversity, and the lives of the elephants killed to prevent this loss.”
This is a highly unscientific and problematic statement. How is ‘society’ meant to make a judgement on this issue when 99% of people have had no training in the science of wildlife management? All too often, members of the public and animal rights NGOs make demands based on emotion rather than considering the outcome carefully. Let’s take a closer look at the situation.
Elephants became a permanent feature in the Kruger only towards the end of the 19th century. The numbers of top canopy trees and hence the nature of the park’s woodlands and riverine forests were thus established under an ecological regime that excluded elephants. The arrival of elephants, however, had no serious effect on the vegetation until their numbers started to explode during the mid-20th century. Since then, their impact has been dramatic.
If we want to have elephants in the Kruger – and surely everyone does – we have to agree on a compromise between the number of top canopy trees and the number of elephants. The current management regime in the Kruger favours the development of an ecosystem in which the number of big trees is seemingly unimportant, while a stable elephant population, without the need for culling, is paramount. It is this attitude that is responsible for the massive destruction of top canopy trees.
And here is the irony: this approach aimed at protecting the elephant is condemning hundreds of calves to death through agonising starvation as the vegetation diminishes. Despite the programme’s obvious cruelty, I am far more concerned about something else: its effect on the long-term biological diversity of the park. Maintaining biodiversity is surely the most important aim of our work in the Kruger, and it is being ignored by the very people who should be most concerned about it.
Top canopy trees are the largest trees in a woodland. Beneath their foliage lies a microclimate of dappled sun and shade. This creates cooler, wetter conditions, vital for second-storey plants – some of which are small trees. Together, these layers create yet another microclimate lower down, where there is even less light, and conditions are cooler and wetter yet. And so on towards ground level.
Thousands of species of animals – including birds, snakes, lizards, insects, spiders, slugs and snails – have adapted to these specialised shade habitats. The diversity of plants is no less impressive, and the food webs are breathtaking in their complexity. It is here where the bushbuck and nyala live; where the tiny Livingstone’s suni survives; where pythons, puffadders, chameleons and other reptiles thrive; where monkeys, squirrels and bushbabies abound; and where specialised bird species such as robins and twin-spots fossick for food in the under-storey plants and leaf litter on the ground.
Some animals, by contrast, are totally arboreal and require continuous canopy tree-tops in which to survive. In such pristine habitats, the vast majority of raindrops strike leaves, twigs or the carpet of dead leaves rather than falling directly on the ground. Consequently, soil erosion is rare and practically every raindrop is absorbed and soaks into the ground. Under these ideal conditions, the death of a top canopy tree creates a gap that allows sunlight to penetrate closer to the ground.
Those plant species that cannot tolerate these conditions perish, and with them so do many organisms that depend on those plants. The extra sunlight, however, promotes an environment that encourages the growth of new saplings. In time, some of these become the new top canopy trees, and so the system recovers. The problem is that over the last 50 years, more than 95% of the park’s top canopy trees have been removed by elephants.
And because they have disappeared so swiftly, the saplings have been unable to replace them fast enough. Indeed, the saplings, too, have been eaten. The under-storeys have therefore simply died away, and the animal species associated with them have disappeared. The unique, layered habitats have changed into more open, arid and uniform scrub-type terrain. Habitats change all the time in nature. But what has happened in the Kruger over the last half century is not natural, and is certainly not desirable. And there is worse to come.
Control by starvation
Some years ago, SANParks did away with artificial waterholes in the Kruger, forcing the animals to live close to natural permanent water. This occurred before the scientists introduced their no-culling regime, but it fitted in neatly with their new plan to lower elephant numbers by starving the animals to death. The plan stipulates that no elephants will be culled. Indeed, they will be allowed to multiply – doubling every 10 to 15 years – in time stripping the riverine habitats of all vegetation.
In order to stay alive, the elephants will then be forced to walk ever-greater distances to and from the water in their search for food. In Botswana, elephants now walk a total distance of 50km a day to find enough food to stay alive. There is no reason to believe this will not happen in the Kruger; indeed, the scientists are banking on it!
The plan is expected to have three effects:
1. The age at which elephant heifers have their first calf will increase from 12 years to possibly 18 years.
2. The interval between calves will increase from four years to six years or possibly more.
3. Lactating mothers will gradually stop producing milk and their calves will not have the energy to keep up with them on the daily trek. The mother elephants will have to make this double journey every day to stay alive. And so their calves will be abandoned – to die from starvation or be attacked by predators.
The scientists who developed the strategy state that the most important factor determining the rate of elephant population growth is the number of calves that survive their first 12 months. They believe that by restricting plant nutrition levels in the Kruger – through a system that effectively starves the calves to death – they will be able to stabilise the park’s elephant population growth ‘naturally’.
Effect on the park
What will happen to the park during this process, particularly during the dry season? Firstly, all the big trees near the rivers will be ring-barked or pushed over. Then the under-storey plants will be eaten down to the ground or die of desiccation. The grass will be the last to go. (Remember that all the other herbivores are grazing and browsing too.) Finally, the soil will be pulverised by animals walking to and from the same overused river pools.
The end result will be a stressed system that cannot provide enough nutrition. Many animals will die. And all this will occur as a matter of course during an average dry season. Should there be a drought, many thousands of animals will perish. This is no wild-eyed, alarmist prediction; over the last 50 years I’ve seen it happen – several times!
And what happens when the rains return? Surely everything returns to normal? Unfortunately, it’s not as simple as that. Because the riverine vegetation has been stripped away, thousands of tons of rich topsoil now lie exposed on or near the river banks. The rain then simply washes it away, along with few bits of remaining vegetation, leaving behind rocky, barren ground.
It is commonly believed that tree roots ‘hold the soil together’. But the main cause of erosion is the impact of raindrops on exposed soil, and erosion is greatest on steep slopes such as river banks. The habitats in the reserve with the greatest biological diversity are riverine forests and evergreen thickets along the rivers. These are also the most fragile habitats.
Yet elephant and other herbivores will be forced to concentrate here during the six-month-long dry season.
Once the soil has gone, these habitats can never be rehabilitated, and the animals that once thrived in them will become locally extinct. Find this hard to believe? Visit the Chobe National Park in Botswana, the Mahango Game Reserve in Namibia or the Lundi River area of the Gonarezhou National Park in Zimbabwe. You will see the results of elephant populations being allowed to proliferate without control.
A national park is not a zoo set aside for the uncontrolled proliferation of elephants. It is a sanctuary whose principal purpose is to maintain the area’s biological diversity. The Kruger, arguably our greatest natural treasure, is losing its rich fauna and flora rapidly because of a blind refusal to control elephant numbers by culling. I fear that, soon, it will start to look like the desert it is destined to become.
Email Ron Thomson at [email protected] or visit www.ronthomsonshuntingbooks.co.za
- This article first appeared in African Outfitter magazine, which promotes fair hunting, biodiversity and sustainable wildlife utilisation.
- The views expressed in our weekly opinion piece do not necessarily reflect those of Farmer’s Weekly.