Question Your World: Which Animal Is Causing Trouble for Lions?

Posted: February 9, 2024

Perhaps you've heard that familiar old saying that lions are the king of the jungle. For a long time now, lions have been considered the top of the ecosystem in their natural habitats. However, recently something has been posing a real big threat to the maned monarch and it’s something very unexpected. So, what's causing trouble for lions? 

Ants are way smaller than lions, but they can certainly make some pretty huge impacts when a colony of ants gets involved. A recently published study is shedding some light on how tiny creatures can make a huge impact on an environment, and even pose a challenge to big apex predators like lions! 

Scientists just observed the cascading effects of an invasive ant species in Kenya. Big-headed ants are being linked with reduced amounts of zebras killed by lions on the hunt. 

How is this possible? Do they sting and bite the lions so much that they give up on hunting for the day? No, this story is not about a direct result, but a ripple effect. 

Let’s start with zebra hunting 101, a crash course in surviving in the wild. To successfully hunt like a lion, one must have a place to hide and sneak up on the unassuming zebra. In this particular environment, historically, lions have had the advantage of acacia trees providing a great hiding spot to lurk behind. 

Recently those acacia trees have been rather empty because elephants have been eating their leaves, getting rid of the hiding spot for lions and making them more visible to prey like zebras. 

The elephants consuming these acacia tree leaves is a newer phenomenon in this area, but it has a direct cause as well and it’s yet another species of ants. Acacia ants, native to the region, would hang out at acacia trees and would bite and sting elephants that came by to snack on the leaves. 

This relationship between the ants and the elephants has helped keep acacia trees full of leaves, providing great hiding spots for lions that are preying on nearby zebras. However, the invasive big-head ants have been very efficient at killing off acacia ants. This causes a chain reaction that makes an impact all the way from ants to lions. 

The big-headed ants kill off the acacia ants, who no longer keep elephants from freely eating acacia leaves, which gets rid of the lion’s hiding spots for ambushing nearby zebra prey, meaning zebras see lions more often and thus escape before being turned into a striped black-and-white snack! 

So, how much of a change have these big-headed ants truly caused? In one region where the study was conducted, five times as many acacia trees than usual suffered significant damage because elephants are now able to eat these trees freely.

Researchers also observed that in tree-heavy areas, lions were twice as likely to successfully kill a zebra compared to the region with fewer tree-cover options. This is an ecosystem-wide change that scientists have been observing for a while now. 

The lion populations are not dwindling because they have started to hunt another meal option, African buffalo! Buffalo is not the ideal meal, though, as they often fight back and require a team of lions to make the kill. 

Scientists continue to urge citizens and governments to take invasive animals seriously. Millions of years of ecological evolution and balance can be jeopardized once an invasive species is introduced, causing ripple effects that can go all the way up to the top of that food chain! 

Stay tuned as scientists continue to monitor and better understand the relationship between these invasive ants and the surrounding ecosystem. They’re small, but make such a big impact. No wonder they’re big headed!