The African Elephant
The two most iconic big game animals in Africa are the elephant and the black rhinoceros but under all the non-intervention elephant management programmes that have been imposed on Africa since 1989 – ostensibly to ‘save’ the elephant from an imagined threat of extinction (which does not exist) – the black rhino is now under severe and genuine threat because there are too many elephants.
The Botswana wildlife management model – or rather Botswana’s total lack of any wildlife management programme – is a good example demonstrating that when elephant population numbers are NOT kept within a sustainable state of balance with their habitats: (1) They eliminate ALL plant foods (edible grasses and browse plants) within an approximate 25 kilometre (10 mile) radius of permanent water; (2) They destroy all the natural habitats within that zone; and (3) They leave a virtual desert in their wake.
Leaving the obvious lack-of-food factor out of the equation for the moment, the very open state of the vegetation surrounding every waterhole – in any and all African national parks that contain elephants – is visually stark and blatantly obvious even to lay people who have untrained eyes. And the degradation is especially noticeable to people (like me) who know what these habitats looked like 50 years ago.
If, at the height of the dry season, you examine the plants that grow within that 25 kilometre radius of the water – in every direction – you will find very few that are edible. And the closer you are to the focal water supply, the more desert-like become the surroundings. This – after 50 years of elephant population MIS-management – surely, stands to reason! And IF, at the beginning of every six-month’s long dry season, there are a few edible food plants growing – derived from the odd seed dropped in the dung of wandering herbivores – within a few short weeks the elephants will have eaten them all up. They would have pulled them out by the roots and consumed the roots, also! And by the end of every dry season there will, again, be no edible plants left at all.
Why would an elephant walk up to 25 kilometres every day to find food, if it was passing edible food plants growing all around it along the way?
Elephants do one of four things when they kill mature trees: (1) They eat the tree’s leaves and they eat the bark off their branches – which branches they rip off the trees with sheer brute force; (2) They prise off (with their tusks) and eat, the inner cambium bark that surrounds every standing tree trunk – which ‘ring-barks’ the tree and kills it altogether; (3) After pushing over a tree they will often dig up its roots and eat them – thus removing important root-stock from the ground (from which many tree species can rejuvenate); and (4) They push over and/or break down mature trees for a behavioural reason that has nothing to do with feeding.
When young elephant bulls leave their maternal breeding herds (at an age somewhere between 12 and 15 years) they enter the world of the big bulls where rank means everything; but when they join ‘the big-boy herds’, the youngsters have NO rank at all. Adult bulls live quite apart from the cows – except that the bigger bulls, when they are in musth (breeding condition), will visit the cowherds to mate.
Once they enter the big bull communities, the younger bulls fairly quickly achieve a loose subaltern rank as a consequence of play-fighting – which they do at every opportunity. This sparring quickly tells each one of them which animals are the strongest within their age class. As the small bulls grow into young adulthood, however, they start to push over trees for no other purpose than to demonstrate their personal strengths to their peers. Tragically, the rate at which these ‘rank-symbolic’ trees are destroyed is entirely a factor of numbers. The more numerous the population-as-a-whole becomes, the bigger becomes the size of each bull herd; the greater becomes the number of bull herds; and the more trees – pro rata – do they push over to determine their rank within those herds.
The biggest elephant bull herd I have ever seen numbered 109 (in Namibia’s Mahango Game Reserve on the Kavango River).
Let’s look at this in another way:
If 100 bull elephant s lived in a particular woodland for 10 days, they would do infinitely more damage to the mature trees in that woodland – simply by pushing them over for rank-attainment purposes – than would 10 elephant bulls do, if they lived in that same woodland for 100 days. In both cases we are looking at 1000 days of ‘elephant pressure’ on the same woodland. The difference between these two examples is ONLY the population density factor. When comparing the respective damage done to the trees, however, the differences are huge
It would appear that maturing bulls, constantly looking to achieve greater rank, are always prepared to demonstrate their strength to the other bulls in the bull herds; and they constantly stimulate each other to push over more and more trees. It would seem that when one bull hears and/or sees another bull pushing over a tree, that audible and/or visual stimulus causes other bulls to start pushing over trees, too – to thus compete! This is common elephant bull behaviour. And nothing is eaten off these trees!
The smaller the bull herds are, the less destructive is their behaviour.
Elephant bulls in the 20 to 40 year age group do most of the damage to mature trees. Bulls aged between 40 and 60 have already established their rank so they don’t normally get involved in the rank challenges.
So it is not just what the elephants ‘eat’ that causes damage to the habitats, it is also what seems to be an imperative and destructive behaviour pattern concerned with elephants negotiating their rank positions. And because this is linked to bull densities, the bigger a population becomes the greater, pro rata, becomes the overall habitat damage.
The cow herds – comprising mature cows, sub-adult cows, immature bulls and juveniles of both sexes – are less inclined to damage mature trees but they eat anything and everything else that is palatable. Thus the breeding herds – as do the big bulls – eat edible grasses and woody plants of all kinds – from seedlings to quite large saplings – so they all contribute greatly to the ultimate total destruction of the habitat.
Every elephant in the population, therefore – when their numbers exceed the carrying capacity of the habitat – contributes towards turning their national park sanctuary into a desert.
In South Africa’s Kruger National Park – since 1960 – more than 95 percent of the very big top canopy trees have been eliminated by the park’s grossly excessive elephant population. When the big trees are knocked down, and their shade is gone, the then unprotected understory plants die out because they are exposed to the desiccating rays of the hot African sun. This state of affairs has caused a major decline in the populations of big eagles – like the Martial Eagle; and also of the giant Ground Hornbill. These very large bird species breed nowhere else BUT in the hollows and crotches of very big trees. Without these trees, these big birds cannot, and will not, breed! And if someone researched this phenomenon properly, I am quite sure they will find hundreds of other major bird and small mammal species that have been similarly adversely affected. For many of these large birds, Kruger National Park represents their last stronghold – their only long term haven for ultimate survival! THIS is one way – a major way – how excessive elephant populations in Africa are adversely affecting the biological diversities in our national parks.
The picture I have just painted is one of destruction. It is one of creating deserts – of reducing woodland habitats to wide-open scrubland with little or nothing for herbivorous animals to eat at the height of every dry season. It is a story of major habitat change in which the closer to the water you get, the less likely is it that you will encounter woody plants of any kind, let alone those that animals will browse upon; or grasses and forbs that animals can eat. And most ‘other’ animals eat the same grass and/or the same browse plants that the elephants eat – and which the elephants totally eliminate. And something everyone can surely understand, the lesser species of animals cannot walk the prodigious distances that elephants can walk each day. So they are forced to remain, for the last three months of every dry season, in barren deserts where no food at all is available anywhere near the water.
All these factors are the reasons why, when elephant populations reach the final stages of their population growth patterns, there is no life-sustaining plant-life left in their habitats at the end of every dry season: No edible grass; no edible browse; and no vegetative cover to protect the soil (or to shelter animals). This is why, at this stage in the elephant population development cycle, all those other species of animals that once shared the elephants’ habitat, go into decline and ultimately disappear. They become locally extinct.