BBC Feature: Big mammals key to tree-ant team
By Anna-Marie Lever
Science and nature reporter, BBC News
At first it may seem counter-intuitive: that preventing large African herbivores from browsing Acacia trees decreases their growth.
This, however, is precisely what researchers report in Science magazine. It is all because of the Acacia's mutually beneficial relationship with a biting ant. Together they fend off Africa's big grazing mammals; but it is these very antagonists that are needed to keep the plant-insect team working in concert.
"Simulating large mammal extinction, by experimentally excluding them from eating the trees, causes the ant-plant mutualism to break down," said co-author Robert Pringle from Stanford University, US.
The whistling thorn tree (Acacia drepanolobium) and the biting ant (Crematogaster) that lives on it form a relationship, evolved over many millennia, in which both species co-operate and in turn benefit from each other.
