The future of big trees and elephants in the Okavango Delta
As one travels through the Okavango Delta, one cannot but be awed by the beauty of the waterways, the large tree islands and the massive grey elephants as they wander from island to island, some with a family of youngsters playing in the water, or chasing egrets through the water.
|By||CORRESPONDENT||Fri 29 Mar 2019|
Any visitor would think this is paradise and just what the “wildest parts of Africa” should be like! And they would be correct. Except for one basic thing. A large portion of these trees are dead!
For many reasons, too many to discuss here, Botswana has become the haven for elephant and for most keen lovers of the wilderness that’s great news – but in reality there is a price to pay for having the large elephant population densities in Botswana.
Elephants are known to devour anything between 200-300 kg of vegetation daily; large portions of this, season depending, is the bark from trees. These trees once “ring barked” are effectively dead, and within a year dry up and sometimes stand there dead for many years.
For the past 35 years, I have spent a great deal of time in Chobe and the Okavango. More and more one is faced with the situation of a tree island consisting of the following example, five dead trees, three ring barked trees but still with leaves on them, and the remaining live trees are two Motswiri (leadwood) trees and four palm trees. Looking carefully, the observer will notice that there is no sign of any young trees to replace the canopy trees either – they are dead or dying!
The ecological importance, totally separate from the aesthetic value of these great trees, is immense. They play a vital role in moving water from one place to another, they create shade for game and people and they provide fodder, nesting for birds and a host of insects.
Our government has an obligation to protect this world famous wetland for its people and the wildlife, and part of that wildlife is the trees and all that goes with it.
The time has come for us to realise that we should be actively protecting our forests and woodland and investigate why elephants are targeting certain species for their bark. There seems to be four main species within the lower part of the Delta: Knobthorn (Makoba), Camelthorn (Mogotlo), Leadwood (Motswiri) and the Birdplum (Motsentsela) and in other parts of the Delta the Baobab tree is also mercilessly attacked. A recent suggestion was to analyse the bark from these “commonly” targeted trees, determine just what it is that the elephant need from this bark, and then produce a “lick or block” much like
farmers use for cattle etc.
These blocks could then strategically be placed by volunteers of lodge operators to alleviate the pressure on the canopy trees. This would be a “short term” solution to a massive problem, but it could at least give our tree assets of the Okavango a chance until a better, long term solution could be found.
It is important to realise, that once these trees are gone, they are gone forever.
Dr. Peter Apps, well known scientist and author says the following: “The analysis for nutrients is pretty straightforward for a lab that does food and feeds routinely, but we would also understand what the elephants are lacking in their diet, and that might be trickier, although analysing food and dung and what changes with the seasons would be a start.” He states further: “This is the kind of non-lethal management that they need to be supporting.”
We do not know all the reasons why elephant aggressively feed on the bark, but a recent study has clues. One of the most extraordinary recent case histories featuring what would seem to be a bona fide example of an animal herbalist, concerned a pregnant female elephant in Kenya’s Tsavo Park. After spending almost a year observing the unchanging daily feeding ritual of this particular animal, ecologist H. [Holly] T. Dublin was puzzled one day when the elephant wandered much farther afield than usual, not feeding until she came upon a small tree belonging to a species related to borage that she had never seen by Dublin to include in her diet before.
Watched by Dublin, the elephant almost entirely devoured the tree, until only its stump remained. Four days later, she gave birth to a healthy calf, and investigations by Dublin revealed that tea made from the leaves and bark of this particular species of tree seemed to induce uterine contractions, since it was often drunk by Kenyan women specifically to induce labour or abortion.” (Shuker 2001:218)
In a nutshell, it is upon us to protect the Okavango as a viable ecosystem for the future generations, not only of our children, but the children of the trees.
*Ronnie Crous is general manager of a leading safari operator in northern Botswana. He has been living in Botswana since 1981 and been involved in conservation activities in Namibia and Botswana for the last 30 yea