How an invasive ant caused lions to change their diet
Research published Thursday has shown how an ant muscled into a Kenyan savannah and sparked such a dramatic transformation in the landscape that even the local lions changed the way they hunt.
The study highlights the potentially profound impacts of invasive species, which are spreading at an increasing rate as human activities give animals, insects and plants opportunities to hitchhike into new territories.
«Oftentimes, we find it's the little things that rule the world,» said Todd Palmer, an ecologist from the University of Florida, who was part of the research team that traced the implications of the big-headed ant on the hunting habits of lions in central Kenya.
«These tiny invasive ants showed up maybe 15 years ago, and none of us noticed because they aren't aggressive toward big critters, including people. We now see they are transforming landscapes in very subtle ways but with devastating effects,» Palmer said.
It all starts with the whistling-thorn acacia trees in the plains of Laikipia, Kenya.
These thorny trees had developed a mutually beneficial relationship with the local acacia ant: The trees provide shelter and food for the ants and in return they use their stinging bite to discourage hungry elephants from devouring the trees.
But the big-headed ant changed all that.
Thought to have originated on an island in the Indian Ocean and brought to the area by the movement of people and goods, these invasive marauders arrived around two decades ago and started killing the acacia ants, leaving the whistling-thorn trees vulnerable to herbivores.
Diminished tree cover poses a problem for lions because they rely on the element of surprise to ambush their prey, notably zebras.
