There is something strangely beautiful about a fire moving across the African savanna.
A line of flames travels through the dry grass. Smoke rises into the sky. Within hours, an area that was golden and covered in tall grass can be black and almost completely bare.
As a guide, I have seen this many times. And every time, the same question comes to mind:
Is this destruction, or is this part of the natural cycle of the savanna?
The answer is not quite as simple as either.
Fire has shaped African grasslands for thousands, perhaps millions, of years. Lightning has always started fires, particularly during dry seasons. But people have also been deliberately using fire for generations. To improve grazing, clear vegetation, influence animal movements and manage the landscape.
Today, controlled burning is still an important management tool in many savanna ecosystems, including parts of the Serengeti–Mara.
But controlled fire is a mixed blessing.
Why burn a savanna?
There are several reasons why conservationists, National Park managements and communities deliberately burn grasslands.
One is to remove moribund grass: old, dead organic material left over from previous growing seasons. If too much old material accumulates, it can cover the ground and prevent new growth from developing properly.
Fire can also be used to control bush encroachment. When grasslands become too heavily grazed, experience drought or lose their natural balance, woody plants can begin spreading into areas that were previously dominated by grass.
A third reason is to encourage healthy grass cover, which can help protect soil and conserve water.
After a fire, new shoots emerge. These young grasses can be highly nutritious and attractive to grazing animals.
This is one reason why recently burned areas can become magnets for Wildebeest, Zebra and other grazers.
But the result depends heavily on how, when and where the fire is used.
Not all fires are the same
Three things are particularly important when deciding whether and how to burn:
The season.
The amount and condition of dry material available to burn.
And the animals present. Particularly grazers that feed on newly emerging shoots.
Timing matters enormously.
Ideally, a controlled burn may be carried out close to the arrival of the first spring rains, when there is still enough dry grass to carry the fire but new growth will soon follow.
The condition of the grassland matters too. A healthy area with dense perennial grasses can respond very differently from an already degraded area or a place receiving very little rainfall.
Burning a poor grassland simply because it has become dry does not necessarily make it healthier.
And there are situations where burning is best avoided! For example when conditions are already poor, rainfall is very low, or the timing is too early or too late in relation to the rains.
In other words, fire is a tool, not a treatment that works everywhere.
Hot, cool, fast and slow
Even the way a fire moves makes a difference.
A head-fire travels with the wind. It can move very quickly and generate considerable heat, particularly above the height of the grass. Because much of this heat is carried above ground, the fire can sometimes pass quickly over perennial grass without completely killing the plant below the soil surface.
But a fast-moving fire can also be dangerous because it can trap animals — or people — that are caught in its path.
A back-fire, on the other hand, burns against the wind. It moves more slowly and generally burns with less intensity, but develops its hottest temperatures directly at ground level. As a result, the plant material burns very thoroughly and completely.
Then there are cool fires, usually conducted under cooler, calmer conditions. These can be useful when the objective is primarily to remove old grass while minimising damage to the vegetation.
Hot fires, particularly under hot and windy conditions, can produce much greater intensity and may be used where controlling woody vegetation is an objective.
For the person standing beside a fire, these distinctions may not be obvious.
For the ecosystem, they can make a considerable difference.
What happens to the animals?
This is where the story becomes complicated.
A Zebra can see a fire coming and run.
A Wildebeest can move away.
A Buffalo can move.
But a beetle cannot simply jump into the next Landcruiser and drive away.
Neither can a snake, tortoise, rat, frog, spider or ground-nesting bird.
Some animals escape by moving ahead of the flames. Others hide underground or in cracks and survive the heat. Some insects can fly away.
Others will not survive.
And even animals that survive the fire may lose food, shelter or nesting habitat.
This is one of the easiest things to overlook when looking at fire from a safari vehicle. We naturally notice the large animals. We see wildebeest returning to the fresh green grass and perhaps predators taking advantage of the open terrain.
We rarely see what happened underneath the grass.
Nests may have been destroyed.
Young animals may have been killed.
An insect population may have been temporarily wiped out.
A small mammal may have survived the flames but lost the vegetation it depended upon for food and protection.
Fire is therefore not experienced equally by all species.
And yet, some animals benefit enormously
Only a few weeks after a burn, the same landscape can look completely different.
Fresh green shoots appear.
Grazers arrive.
Insects return.
Birds follow.
Predators may take advantage of the concentration of prey.
For large herbivores, recently burned areas can provide exactly what they need: short, young and nutritious grass.
This is particularly interesting in ecosystems such as the Serengeti–Mara, where grazing, rainfall, grass growth and fire all influence one another.
Large herds consume enormous quantities of grass. By doing so, they also reduce the amount of dry material available to burn.
Fire then removes some of what remains and stimulates another phase of growth.
The animals are not simply responding to the landscape.
They are helping to shape it.
Fire and the great migration
The relationship between fire and the great wildebeest migration is sometimes misunderstood.
The migration does not happen simply because people burn the grass.
Rainfall, soil nutrients, fresh plant growth and grazing pressure all play enormous roles in determining where the herds move.
Fire is one part of this much larger system.
Recently burned areas can provide attractive grazing, but the wider landscape needs a mixture of habitats: short grass, tall grass, recovering areas and places that have not burned at all.
This mixture is important because the Serengeti–Mara is not just a habitat for wildebeest.
It is home to thousands of other species.
And what is beneficial to one species may be disadvantageous to another.
Perhaps the most important thing is: “what NOT to burn”
This is one of the principles of good fire management.
A landscape does not necessarily need to be completely burned.
Leaving unburned patches provides refuge for animals and preserves different types of vegetation. Over time, burning different areas at different times can create a mosaic of habitats.
Some patches may have recently burned.
Others may be covered in tall grass.
Some may contain dense shrubs.
Others may be heavily grazed.
This variation is important.
A completely uniform landscape, whether completely burned or completely unburned, can support fewer ecological niches than a landscape containing many different conditions.
Firebreaks and controlling the flames
Controlled burning also means controlling where the fire can go.
Firebreaks are used to reduce the chance of fire spreading from one area into another. Roads, rivers and deliberately cleared strips of vegetation can all act as barriers.
This is particularly important when fires are burning under dry or windy conditions.
Because once a fire becomes too large or intense, it may no longer be a management tool.
It becomes a wildfire.
And that distinction can be very important for both people and wildlife.
But what is a "natural" fire?
This may be the most difficult question of all.
A lightning strike is clearly a natural source of fire.
But humans have been deliberately burning African landscapes for thousands of years.
So if people light a carefully controlled fire today, is that automatically unnatural?
Perhaps not.
The bigger question is whether we are maintaining an ecological process that belongs in that landscape — or whether we are changing it too much.
Modern protected areas are very different from the landscapes of the past. Wildlife numbers have changed. Livestock grazing has changed. Human settlement has changed. Some areas are now protected from fire, while others are deliberately burned.
There may therefore be no perfect historical version of the savanna that we can simply recreate.
Instead, conservation often becomes a question of balance.
A mixed blessing
Controlled fire can remove old grass, encourage fresh growth, maintain open grasslands, recycle nutrients and create valuable feeding areas for grazers.
It can also destroy nests, insects, small mammals and vegetation that other species depend upon.
The difference may come down to timing, frequency, intensity, location and scale.
A carefully timed, low-intensity fire through healthy grassland is not the same thing as a hot fire racing through a drought-stricken landscape.
A small patch of recently burned grass is not the same as thousands of hectares burning at once.
And one fire is not the same as burning the same area again and again.
Perhaps this is why fire is such a fascinating part of the African wilderness.
It is neither simply destruction nor simply renewal.
It is one of the forces that continually reshapes the savanna.
The flames may disappear within hours.
But the consequences can remain for months or years.
And somewhere between the blackened ground, the returning insects, the first green shoots and the herds moving in to feed lies the real story of fire:
Not whether it is good or bad, but whether we understand when it is needed, where it belongs, and what we might lose along the way.
