UW-led research shows invasive ants change lion predation in Kenya

New research led by a University of Wyoming graduate student shows that invasive ants in a Kenyan savanna have caused lions to change their predatory behavior.

During a recent appearance on Sheridan Media’s Public Pulse, UW Director of Institutional Communications Chad Baldwin shared the news of this discovery. 

Detailed in the journal Science, the researchers found that the invasion of big-headed ants at Kenya’s Ol Pejeta Conservancy makes lions less effective at killing zebras, their primary prey. 

C. Baldwin 

The invasive ants kill native acacia ants that protect a tree known as the whistling-thorn tree from elephants and other herbivores, resulting in less tree cover for lions to ambush zebras.

According to UW, over the past two decades, invasion of the big-headed ant — thought to have originated on an island in the Indian Ocean — has disrupted the symbiotic relationship between whistling-thorn trees and native ants. Big-headed ants kill the native ants but don’t protect the trees from elephants, allowing the massive herbivores to browse and break trees at five to seven times the rate of uninvaded areas.

According to the research, there is good news as the lion population hasn’t declined since the insect invasion, likely because lions have switched their diets from zebras to African buffalo, which are equally at risk of lion predation in invaded areas.

Baldwin said there are many instances where the introduction of one invasive species changes the ecosystem so dramatically, predators adapt their behavior, sometimes in negative ways. 

C. Baldwin 

To learn more about this research, click here.