Jacob Gohin, a wildlife ecologist at the University of Wyoming, was curious about how the destruction of trees might have affected other organisms in the community. “Lions are much more successful in killing their prey in thickets,” he says. But does the more open savanna make it more difficult for lions to hunt zebras?”
The Ol Pejeta Conservation Area in Kenya’s Laikipia County is the perfect place to look for answers. There, researchers considered several plots of 2,500 square meters in an area of Savannah for study. They are in each plot, visibility in the landscape, density of zebra population (Equus quagga), tracked the presence of giant ants and the killing of zebras by lions. The researchers also took six female lions and attached GPS collars to them to investigate the difference in their activity in different areas.
With the loss of trees in the grasslands of eastern Kenya, the rate of zebra predation by lions has decreased
After three years of monitoring, Gohin’s team achieved remarkable results. Elephants stripped and felled trees without native ants seven times faster than trees with protective ants. The tree and bush cover decreased dramatically, making it difficult for lions to ambush zebras. In contrast, areas free of invasive ants had whistling thorn foliage that the lions could hide behind. The killing of zebras by lions was almost three times higher in areas that were not attacked by giant ants.
Caitlin Gaynor, an ecologist at the University of British Columbia who was not involved in the new research, said it’s always hard to say “this caused it” in ecology because there are so many species interacting. But in this case, a direct comparison of the invaded and intact areas revealed the role of the ants.
The surprising thing was that despite the reduced access to the main prey, the population of lions remained stable in the study area.
Relying on another study, the researchers found that the killing of zebras in 2020 was only 42% of the hunting activity of lions, while it was 67% in 2003. During this time, the killing of African buffaloes (Syncerus caffer) hunting activity of lions had increased from 0% to 42%.
Douglas Camaro, lead author of the new study published in the journal science “We don’t know what’s going to happen in the future,” he says. “It is very difficult for lions to kill buffaloes and sometimes they kill lions when they fight.”
Experts don’t know if buffalo numbers will decline if lions continue to hunt, or if plant communities and fire patterns will change as hunting pressure on zebras decreases.
Some researchers think that in order to deal with the advance of invading ants, which is currently about 50 meters per year, the way they spread should be studied.
