The number of zebras killed by lions has decreased due to a “chain reaction” caused by the presence of invasive ants.
When a lion chooses to pursue a zebra, it appears unstoppable. However, recent studies have revealed that these large predators are being hindered by a small adversary: ants.
Researchers have discovered that the expansion of big-headed ants in eastern Africa triggers a scenario where lions reduce their number of zebra kills.
According to Prof Todd Palmer from the University of Florida, who worked on the research, the results were unexpected. He expressed his shock, saying that he was stunned. The decrease in kills seems to be a result of a disruption in the important connection between native ants and their tree habitats, leading to a decline in cover for lions.
According to Palmer, the finding emphasized the significance of connections between different species. He noted, “While conservation is typically discussed in terms of individual species, it is the interactions between them that serve as the foundation for the entire ecosystem.”
Acacia ants protect whistling-thorn trees by biting and stinging elephants looking for a snack. In return, they get nectar and shelter. But big-headed ants – an invasive ant species that can take over whistling-thorn trees by killing adult acacia ants and eating their eggs and larvae – offer no such protection.
According to Palmer and colleagues in the journal Science, elephants in invaded areas consume and damage trees at a rate that is five to seven times higher than in uninvaded areas.
In order to examine the larger ecological effects, Palmer and his team initially analyzed several locations in Laikipia, Kenya, some of which had elephant populations and others where they were not allowed.
The researchers discovered that the presence of big-headed ants and elephants resulted in a decrease in tree coverage and a significant rise in visibility levels.
The scientists constructed a computer simulation using data from the natural environment to investigate the potential impact of big-headed ants on zebra behavior, including their movements and the locations where they are killed, as well as the movements of lions.
The group discovered that zebra deaths were nearly triple the amount in locations with poor visibility and no big-headed ants, compared to areas with good visibility and the presence of big-headed ants. However, further examination eliminated the possibility of a correlation between zebra population or lion behavior, indicating that the decrease in kills may be due to the increased visibility of lions to their prey.
According to Palmer, lions face more risk when hunting without enough trees for cover. This can make it more difficult for them to capture their prey, such as zebras.
The researchers have reported that the number of lions remains consistent, likely due to a shift in their prey from zebras to buffalo. However, Palmer expressed worry over the inability to control the expansion of big-headed ants.
The speaker stated that if the invasion persists, there will be a significant loss of acacia trees. This could have a major impact on the ecology of the area, as these trees serve as a vital food source for various species such as rhinos and giraffes.