Kruger Park’s biological diversity is in serious trouble! Part 7.

Elephant Management in Kruger National Park (7)

I would like you now to imagine that the perennial plants which grow in a game reserve (representing the sanctuary’s many different habitats) can be likened to a hedge in a well-groomed garden. Every year the hedge is trimmed with a pair of shears by the gardener; when he cuts off all that year’s new growth. The hedge then takes on the same shorn appearance that it had at the same time the previous year; and in all other previous years. So the gardener returns the hedge to its “man-desired” stable state every year.

NB: I refer to the hedge (after trimming) as representing the “parent” plant stock; and those parts of it that were trimmed off as the annual plant growth surplus. Both the parent plant stock AND the annual growth surplus are edible; but in a   well-organised game reserve – where all animal populations are within the carrying capacities of their habitats – (theoretically) only the annual plant growth surplus is ever eaten.

If the gardener does not cut off the new hedge growth every year, the hedge will expand in length, breadth and height – growing bigger and more bulky every year – until it reaches the maximum of its growth potential. Woodlands do the same thing when they are unused by herbivorous animals. Botanists refer to this maximum growth potential as being the woodland’s ‘climax state’.

A wildlife manager strives to manage a game reserve in much the same way that a gardener manages hedgerows – except that the wildlife manager allows the animals to do “the hedge trimming” for him. Nevertheless, their desired objectives are the same. The wildlife manager’s goal is to have the game reserve habitats return to exactly the same state they were in at the beginning of the previous year’s growing season; and as they were at the beginning of all previous growing seasons. If he can achieve that objective, the biological diversity of the game reserve will remain forever safe.

This is not difficult to do when the herbivorous animal populations are not excessive. (“Excessive” means there are more animals than the habitats can sustainably carry).

When an elephant (or any other animal species) population becomes excessive, however, they eat ALL the annual plant growth surplus AND they start to eat the parent plant stock, too. If they didn’t, they would die. Even though that is an undoubted fact, the excessive numbers of elephants, every year, eat more and more of the parent plant stock until there is nothing left. The “hedge” disappears. When that stage is reached the elephants and everything else will die.

I return your attention now, to man’s conservation priorities.

Man’s FIRST conservation priority is for the sustainable and wise use of the SOIL – because without soil no plants will grow.

His SECOND conservation priority is for the sustainable and wise use of PLANTS – because without plants there would be no animals.

And his THIRD (and last) conservation priority is for the sustainable and wise use of animals. Animals come last on this hierarchical conservation priority list, not because animals are NOT important, but because they are LESS important than the soil and plants.

Plants provide the environment with many beneficial things; one of the most important of which is that they protect the soil from erosion by the sun, the wind and (especially) the rain.

“A raindrop impacts with bare ground, loosening the surface soil particles, and washing them away into the sea.”

So when elephants remove all its plant cover protection, the soil is laid bare. The most important element (the soil) of the environment will then be exposed to total destruction. Thus, can too many elephants change once healthy national park ecosystems into deserts?


 Elephants that are contained in a game reserve by fences cannot disperse, but fences are not the only thing that contains elephants within a game reserve. When human population densities exceed 15 people per square kilometre (or 40 people per square mile) elephants will vacate even the best of habitats – even when there are no physical barriers (like fences) to restrict their movements. Natural dispersals will then not happen so the elephant population will become ever denser. And the more concentrated the population becomes the more permanent damage will they do to their habitats. THIS is the bind that the Kruger National Park is in today!


Today there are about 750 million people living in Africa south of the Sahara Desert. By the end of this century – by the year 2100 – there will be more than 4 billion people living in this same region (UN Statistics). So the influence of heavy human population pressures on dispersing and excessive elephant populations is not going to get any better.


When elephants cannot disperse (due to fences) or won’t disperse (because there are too many people living outside their game reserve boundaries), once they have eaten all the annual plant surpluses, they start to eat into the parent plant stocks of their habitats. This begins a spiral of destruction that cannot be halted without massive elephant population reduction. There is, however, no shortage of food at this early stage of what will soon become a massive population explosion. And because the food is still not a limiting factor, they will continue to double their numbers every 10 years; and, exponentially, their population explosion becomes huge.

You will note in Figure 5 above, that it took 50 years for the population to reach the 80 percent level of its habitat carrying capacity; and only another three years to exceed the 100 percent barrier.

You will also note that just as soon as the population exceeds the carrying capacity of its habitat, the ecosystem starts to lose soil; plants; and animals. Consequently, its overall biological diversity comes under very severe threat.







Ron Thomson

I am NOT a ‘trophy hunter’ - and never have been. I am not involved in the trophy hunting safari business. I am also not a game rancher. But I have ‘administratively controlled’ professional hunters and safari outfitters in my capacity as a government game warden. I am an 80 year old ex-game warden with 60 years of continuous experience in hands-on wildlife management, and national park management, in Africa (1959 to 2019). In breakdown, I have 24 years experience in the management of national parks in Rhodesia/Zimbabwe - and in the management of the wild animal populations that lived inside those national parks; one year as the Chief Nature Conservation of the Ciskei in South Africa; three years as Director of the Bophuthatswana National Parks Board in South Africa; and I worked for three years as a professional hunter in the South African Great Karoo (taking foreign hunters on quests for plains game trophies). I discovered, however, that professional hunting was not my forte. I worked as an investigative wildlife journalist for 30 years in South Africa. I have written fifteen books and hundreds of magazine articles on the subject of wildlife management and big game hunting in Africa. Five of my books are university-level text books on wildlife management. I am a university-trained ecologist; was a member of the Institute of Biology (London) for 20 years; and was a registered chartered biologist for the European Union for 20 years. I have VAST experience in the “management hunting” of elephants, buffaloes, lions, leopards and hippos (as part of my official national park work in the control of problem animals); and I pioneered the capture of black rhino in Zimbabwe’s Zambezi Valley (1964 - 1970). My university thesis was entitled: “The Factors Affecting the Survival and Distribution of Black Rhinos in Rhodesia”. Look at my personal website if you want any further details about my experience:

Ron Thomson has 280 posts and counting. See all posts by Ron Thomson

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