I would like to take the opportunity to write something on what most perceive as a negative aspect in the natural cycle of life on the savannas of Africa with particular reference to the amazing Kruger National Park in the north eastern corner of South Africa.
The Kruger National Park was proclaimed 31 May 1926, when two separate game reserves, the Sabi game reserve to the south and the Shingwedzi Game reserve to the north, were joined by incorporating the corridor of land that separated them into one pristine, unified chunk of savanna in what is known as the Bushveld in the Lowveld of the Mpumalanga and Limpopo provinces in South Africa.
The Kruger National Park is the largest and oldest national park in the country and will be celebrating its 100th birthday next year, and what an icon it has turned out to be.
It is just short of 2 million hectares in its original form (and is as we speak as new land is incorporated under different management principals) and finds itself wedged between the eastern escarpment formed by the northern Drakensberg Mountains to the west and by Mozambique in the east.
The Lowveld and the Kruger Park are prone to droughts that tend to come in fairly predictable cycles approximately every ten years or so these droughts tend to last for a year or so and can be devastating to all biotic (living) communities from the grassland of the central plains to the thickly wooded savannas in the southern sections of the park but it is when a shorter ten year cycle overlaps in time with a longer, say fifty year cycle that the real face of a drought appears.
In definition a drought is a prolonged period of abnormally low rainfall that leads to a shortage of water. That prolonged period of time is critical to the effect a drought has on the land.
In the context in which I write, we are talking about two different droughts that take place in these low lying savannas.
The collective area is referred to as the Lowveld, the low lying area that borders the similarly low lying and coastal areas of neighbouring Mozambique to the east. The entire area lies at an altitude of between 170 and 600 meters above sea level between (ASL)
The area falls within the summer rainfall region which is true of the entire country of South Africa except for the south western extremity of the country, around Cape Town which falls within a proportionately smaller winter rainfall area.
Under normal rainfall conditions the annual dry winter periods in the Kruger National Park undergoes a natural cyclic drought where there is little to zero rainfall over a period of approximately 6 months after the seasonal winter drought the rains arrive after the spring days lengthen, heating the atmosphere producing the anticipated rains.
The arrival of the austral winter causes a cyclic winter drought with shorter days, longer nights and lower temperatures resulting in less daylight hours. The combination of these factors has a profound impact on the vegetation that affects the entire ecosystem from the smallest insects to the largest mammals, something the park is world famous for.
This then is the annual cycle, a drought period that all life has adapted to accommodate and live with over the millennia but there is another type of drought cycle. A longer and far more severe drought that occur on a less frequent but inevitable basis.
These droughts last longer than the annual, seasonal droughts and have a massive impact on the spring growing season when limited rains fall especially in the low lying areas at the start of the spring when the weather starts to warm and the days get longer after the cooler winter months.
When these dry conditions begin to make themselves felt, it becomes a period of great stress and anxiety for all forms of life on the land, including mankind as the drought begin to impact the environment.
African villagers throughout the region have crops to sow and later harvest, herds of cattle, sheep and goats to feed and water and have to search further and further afield for both enough water and grazing to satisfy the thirsty herds.
But these people, the salt of the earth, have seen it all before and know how to get through these difficult times. Farmers and wildlife managers and those living close to the soil become obsessed with the weather.
Fervently they watch the weather reports or listening to them on their radios, at villages and towns throughout the country people meet, greet and talk about the weather, comparing notes and predictions on when the rains will break while the daily temperatures continue to rise. Small cotton wool size clouds quickly develop into huge, white billowing thunder heads before dissipating once again without a drop falling each evening.
Disappointment turns to anticipation the next day and the day after, each day followed by disappointment once again until finally there is a massive accumulation of clouds accompanied by a rumble and crashing of thunder, split by eye watering lightning strikes snaking sharply across the sky. Powerful winds can be heard whispering at first then rustling and sowing through the trees as the wind gathers speed, gathering in volume until it thrashes the trees and bush with leaves, twigs and branches flying everywhere before passing, leaving silence once again in its wake.
The rains might still not arrive, the promise passing with the rush of the wind.
When the rains refuse to arrive, the land prepares itself for the hardships brought on by a prolonged drought. A stillness descends over the bush, a quietness that spreads like a calming blanket enveloping the land, this is the second hibernation, the warm hibernation, after the winter hibernation, it slows the cycle of life down to an idle, slowing everything down into a survival mode as the effort to preserve precious resources, to preserve energy, to preserve life itself to hang on to life for as long as it may be necessary before the anticipated rains finally arrive, and arrive they will.
The spring hibernation is different from the winter hibernation, here some of the trees have started to send out their buds, thorn trees like the Knob thorn develop their sweet inflorescence that fills the air, bees and other insects arrive for the local scented bounty. A light dusting of rain might stimulate some of the shrubs and trees to send out new leaf growth in anticipation, but they have been fooled, and the shimmering heat remains day in and day out, distant clouds pop up gather height and spread wide with dark underbellies and then drift off on the wind to dissipate in the distance once again.
The new leaves slowly wither and die the promise of spring and the production of life giving food for the herbivores disappears into the heat haze while the antelope, buffalo and herds of wildebeest and zebra start trekking in search of the promise of food over distant horizons, the familiar scent of far off rain, softly drifting on the breeze gently tugging them, pulling them by their noses across those distant horizons search, searching for the fresh green shoots born of the promise that was before them.
The more sedentary impala and kudu who are restricted in their movements, probe ever deeper into the thorn thickets searching for blades of grass or a shriveled, brown, hidden fruit lying in the tangle of stems and trunks.
Slowly the herbivores loose condition, ribs appear under shaggy unkept coats, hips protrude. Later bellies extend bloated with indigestible food, and lack of water, eyes become glazed and the daily trek to the last water in the dried riverbeds become longer and further from the feeding grounds, longer again as each pool in turn succumbs to the baking, unshaded, relentless heat of the African sun.
Crocodiles leave dried and dusty river beds in search of somewhere to hide, darkly, resting patiently in excavated dens away from the desiccating heat of the sun.
Hippos, vulnerable to the power of the sun, sweat sun protection. They leave drying mud wallows and puddles of water, puddles too small to offer their huge bulk, under tender skin, the relief they crave. The skin, sagging over protruding bones, vertebrae clearly visible can be counted through the thick hides as they seek protection from the intense gaze of the unforgiving sun and they search for alternative respite, a shallow pool or sticky mud wallow but in most cases, there is none.
Herds of buffalo walk head bowed, nose all but touching the dry, dusty, red dirt. The dust lifting from each breath, shuffling behind each other as they part walk, part stumble, hooves lazily click, click, clicking against pebbles and stones on their long walk to the waterhole. Coats are a dull brown with ribs, hips and necks scrawny form the lack of good grass.
These long droughts are used by nature to level the playing fields for those on the veld (field). During the normal rainfall years when the rains fall as they should in the spring, through to the summer, when grasses grow tall with trees full of leaf and flower that the herbivores, the impala, kudu, waterbuck, wildebeest, buffalo and their companions the zebra are fat and full of energy. Shiny coats cover plump rumps and glossy legs and thighs. Fat saturated muscle gives them the advantage over their predators the lion, hyena, leopard, cheetah and wild dog.
This is a lean time for the predators, the carnivores, the animals that need to eat the flesh of others to survive. They now need to work harder to get enough to feed themselves and their young, the tables have been turned and they in turn grow lean and succumb to infections of parasites that further weaken them making it even more difficult to find the energy and stamina to complete the chase successfully, to hunt and stay healthy which they must do to survive..
There is more than enough quality food for all of the herbivores to go around, and the thick green cover provided by the vegetation makes it easier for the prey animals to conceal themselves and to avoid being caught in their panicked flight from their enemies.
But conversely, with the advent of a serious drought the scales are inexorably weighted once again in favour of the predators, this is the fearful symmetry of nature and soon, once again, it is the predators that have the advantage over their prey who lose condition becoming weak and vulnerable to their enemies.
This continuous cycle of feast and famine has a massive impact on the vegetation and soil in a protected area. Herbivore population over a series of good rainy season, breed successfully and their populations grow exponentially where these increased numbers have a growing impact on the vegetation they eat, especially the vegetation closer to the regular watering points they use.
When the wet cycle is broken by a number of dry years, these increasing herbivore numbers exert pressure on the food resource, grazing and browse and the abundance of herbivores becomes a burden to the system as food and water resources dwindle, the weakened ones die off or are caught as food by full bellied predators and so the cycle continues.
The big winners during the prolonged droughts and the gigantic tussle for survival between the predators and their prey are the scavengers, vultures, jackals and hyenas are the main scavengers in the ecosystem but there are many others mostly unseen, the flies and their larva, the Dung beetles and bacteria that gobble up carcasses with invisible speed right there where they lie in the bush.
It is the large scavengers that provide the vital function of cleaning up the carcasses of fallen animals, too many for the carnivores to consume the carcases are soon pecked clean by the hundreds of vultures, while hyenas clean and crush even the largest bones turning them into characteristic white droppings that form, territorial “fence posts” of almost pure calcium, deposited along the well-trodden foot paths and tracks that form the seemingly chaotic maze of a functioning and invisibly structured ecosystem.
It is a magnificent symmetry, a balancing act of infinite variation but always the same as the huge, living, breathing, consuming, excreting, multiplying beast of the ecosystem is alive and well, the sum of all the biotic, the living, components as well as the abiotic, the lifeless components, drawn together in a living body, that creates a near perfect system of perpetuation where nutrients flow from soil to leaf and tree to antelope or elephant through the lion to hyena on, into a fly, an egg and maggot, a chrysalis and back to a fly to die and rest momentarily in the dusty soil at a dying, drying water hole before being drawn up by an ephemeral plant growing quickly before withering away, goaded into life from a shrivelled seed by life giving moisture of the first rains to break the deadly drought, the fragile plant giving precious energy when delicately nibbled by the sheer perfection of a tiny Steenbok.
Words and images by Alan Fogarty
