Lions are the undisputed kings of the African savanna, but their reign is being challenged by a seemingly insignificant enemy: a tiny invasive ant species.
In this article, we will explore how these ants are altering the landscape and the food web in an East African wildlife area, and what this means for the future of lions and other animals.
The Ant Invasion and its Consequences
Geranimo/Unsplash
The ants in question are known as the big-headed ants (Pheidole megacephala), and they are native to southern Africa. However, they have been accidentally introduced to many other regions of the world, including East Africa, where they have become a major pest.
These ants are small but voracious hunters of insects, and they can wipe out the colonies of native ants that live in the acacia trees.
Why does this matter? Because the native ants have a mutualistic relationship with the acacia trees, meaning they both benefit from each other.
The ants nest in the trees' bulbous thorns, and in exchange, they defend the trees from herbivores, such as elephants, giraffes, and zebras, by biting and stinging them. This way, the ants protect their home and the trees maintain their leaves.
However, when the big-headed ants invade, they disrupt this balance. They kill the native ants, but they do not defend the trees from the herbivores.
As a result, the acacia trees are being defoliated and destroyed by the elephants, who prefer to feed on them. This leads to a loss of tree cover in the savanna, which has a cascading effect on the ecosystem.
The Impact on Lions and their Prey
One of the most affected animals by the ant invasion are the lions, the apex predators of the savanna. Lions are ambush hunters, meaning they rely on stealth and surprise to catch their prey.
They use the tree cover to hide and stalk their preferred prey, such as zebras, wildebeests, and gazelles. However, with less trees, the lions have fewer places to conceal themselves, and their hunting success rate drops.
To cope with this challenge, the lions have to change their hunting strategy and their diet. They have to avoid the areas where the ants have reduced the tree cover, and they have to target different prey, such as buffaloes.
However, buffaloes are larger, stronger, and more aggressive than zebras, and they often travel in large herds. This makes them more difficult and dangerous to hunt, and the lions have to risk more injuries and fatalities.
The ant invasion also affects the prey animals, such as zebras and buffaloes. Zebras are losing their food source and their shelter, as the acacia trees are being eaten by the elephants.
They have to migrate to other areas, where they may face more competition and predation. Buffaloes, on the other hand, are facing more pressure from the lions, who are switching to them as their main prey. They have to defend themselves more often, and they may suffer more losses.
The ant invasion is a clear example of how a seemingly minor change can have profound and unpredictable consequences for an entire ecosystem.
The tiny ants are altering the landscape and the food web in a way that threatens the survival of lions and other animals. The question is, can the savanna adapt to this new situation, or will it collapse?
There is no easy answer to this question, as the ant invasion is still ongoing and its effects are still unfolding. However, some possible scenarios can be envisioned.
One scenario is that the savanna will reach a new equilibrium, where the ants, the trees, the herbivores, and the lions will coexist in a different but stable way.
Another scenario is that the savanna will undergo a regime shift, where the ants will cause irreversible changes that will transform the savanna into a different ecosystem, with different species and functions.
A third scenario is that the savanna will be restored, either naturally or artificially, by removing the ants and restoring the trees and the native ants.
Whatever the outcome, the ant invasion is a reminder of how complex and fragile nature is, and how human actions can have unintended and far-reaching consequences.
It also shows how important it is to study and understand the interactions among different species, and how they affect each other and the environment.
By doing so, we may be able to prevent or mitigate the impacts of invasive species, and protect the biodiversity and the beauty of the savanna.
