Native ants that protect the whistling thorn tree (by "swarming up the nostrils of African bush elephants") are being overwhelmed by invasive "big-headed ants." That's allowed elephants to destroy undefended thorn trees at a high rate. Such trees are a favored hiding place of lions, allowing them to effectively hunt zebras, So the lions started hunting buffalo instead:
“We don’t know what’s going to happen going forward,” says ... a wildlife ecologist at UW and lead author of the new study. “It’s very difficult for lions to kill buffalo. It’s a lot of energy compared to [hunting] zebra, and sometimes buffalos kill lions when they’re fighting.”
Other experts wonder whether buffalo numbers will decline if lions continue to hunt them, or whether plant communities and wildfire patterns will change as grazing zebras face less hunting pressure.