There are few land mammals that command the presence and have the intellect of elephants, the largest land mammal with whom we so fortunately share our planet. There have possibly been more wildlife books, articles and documentaries published on elephants than on any other wild mammal, yet they still rank as one of the most misunderstood animals. What we call destruction by elephants is often the exact opposite. Join me on an important rethink of the many positive effects that these bush architects have on their environment
Most waterholes in a wild ecosystem were engineered by elephant action over millennia. All mammals eat soil to acquire mineral salts. Browsers tend to eat more soil than grazers, and elephants eat more of it than any other herbivore. The depressions they create fill with rainwater to form small waterholes. When these begin to dry up and turn to mud, warthogs may wallow, expanding the hole and sealing the bottom off in a process called puddling.
The following year, after the rains, when the dry depression has increased in size as a result of more soil being eaten and ongoing wallowing, it may be puddled by buffaloes and then rhinos and, years later, by elephants. It’s estimated that each adult elephant excavates about a ton of soil a year from the various licks and waterholes – about 2.3kg of silt when drinking, and two bucketful’s of mud each time they wallow in, kick and throw it over their bodies. This sealing process enables the pan to hold water for much of the dry season and benefits all forms of wildlife.
Because of their size, longevity, and intelligence, elephants are the main highway builders of the bush. With their expansive knowledge of home ranges, garnered over millennia, they have created U-shaped highways linking feeding areas to waterholes and rivers – highways that other wildlife use. When flying overhead, it’s common to see their trails like spokes in a wagon wheel radiating out from a waterhole. For hikers, there’s no easier way to travel than on an elephant highway. Elephants follow the best contours to each summit and valley, often taking you through tunnels of impenetrable jesse-bush bushwillow (where an encounter with a black rhino used to be a strong possibility).
Elephants eat large quantities of acacia and other pods. The warmth of their belly swells the seed, and their stomach movement rasps and scours it, all of which assists in the germination process. All trees can germinate on their own, of course, but the process is favourably accelerated by passing through an elephant’s belly. Germinated seeds, embedded in the bolus, are often dropped in the dung pile a good distance from where they were eaten.
The Lower Zambezi River, on the Zambian side downstream of the Chongwe River, is a good example of this redistribution and replanting process. Tens of thousands of Faidherbia albida have grown over the past 30 years, all the way down to the Mushika River, a distance of around 80km. They are pioneer trees of such areas and proliferate on sand banks and sandy islands. Their gardeners are elephants, which move to the islands daily to feed off the pioneering sedges and Phragmites reeds. While there, they deposit their load, which includes Faidherbia seeds from the mainland.
As these islands are without baboons and impala, which pluck and nibble off all the young shoots, these young seedlings have the opportunity to grow into adulthood, and have produced forests that now line the channels of the river terraces. Over time, the river changes its course and these islands join the mainland, where the trees drop tonnes of pods that feed multitudes of herbivores and omnivores, from tiny gerbils to the next generation of elephants.
In agriculture, pruning is undertaken to remove parts of plants, such as old branches, buds, or even roots. For a while, the plant may not look its best, but pruning encourages healthy regrowth and helps increase the yield or quality of flowers and fruits. In nature, wind, ice, snow and salinity can cause plants to self-prune. This is called abscission. In all wild areas that are home to elephants, the vegetation looks modified at the end of the dry season, the culmination of a year’s pruning. Four months into the rainy season, these stark wooden statues explode into green leaf, making the same trees almost unrecognisable. Elephant pruning ensures that a tree is kept down at browse level for all leaf eaters, from dik-diks at the base to giraffes, which shape its canopy.
Of course, most humans would prefer to see a majestic grove of cathedral mopane trees rather than an orchard of scrub mopane modified by elephants. But what can feed from such a high canopy? These trees have grown out of the browse level of even giraffes. So which grove is the more useful?
When elephants push over a mopane tree, the tap root often remains intact. The tree continues to grow on its side, with new branches coppicing towards the sun. This tree is very much alive and offering food to a much wider range of creatures down at this level. So the state of vegetation of a national park or elsewhere should not be judged at the end of the dry season. It’s what you see at the end of the rainy season that reflects its true health.
There’s further value in elephant action on trees: woody species encroach on grasslands and, if left unchecked, this process can take over grassy areas and dry vlei lines. By pruning and killing encroaching trees, elephants help protect the grassland for grazers, and help to create balance.
Gonarezhou National Park in Zimbabwe has one of the highest densities of elephants in Africa.
Niassa Reserve in Mozambique, once home to more than 13 000 elephants, now sadly have seen an 85% drop to only 2 000 due to poaching.
South Africa’s Addo Elephant National Park is home to around 600 elephants, and has some of the densest concentrations of elephants in Africa.
Due to laws and policy, Botswana hosts the world’s largest free-ranging elephant population. Visit the Chobe National Park to see these giants.
The rare desert-dwelling elephants of Namibia can be seen in the Etosha National Park.
Extract from The Last Elephants, Penguin Random House.
This article is featured in our August-September 2019 issue of Places Magazine. Fly fastjet to South Africa, Zimbabwe or Mozambique.