Weekly Science & Technology Report

A species of acacia tree in Eastern Africa seems to be protected from elephants by ants, according to new research from scientists at the Universities of Wyoming and Florida.The researchers conducted a series of studies in Kenya, and found that the acacia trees in areas heavily trafficked by elephants simply get pummeled without protection from their tiny ant bodyguards.?It really is a David-and-Goliath type of story, where these little ants are up against these huge herbivores, protecting trees and having a major impact on the properties of the ecosystems in which they live," said Todd Palmer of the Mpala Research Centre in Kenya and the University of Florida. "In the words of the renowned biologist E.O. Wilson, 'It's yet another example of how the little things run the world.'"The ants seem to be major ecosystem players in the African savanna, said Palmer and his colleague Jacob Goheen at the University of Wyoming.The researchers stumbled onto the finding after observing that one species of a

"It really is a David and Goliath story, where these little ants are up against these huge herbivores, protecting trees and having a major impact on the ecosystems in which they live," Palmer said. "Swarming groups of ants that weigh about 5 milligrams each can and do protect trees from animals that are about a billion times more massive."
"Our results suggest that plant defense should be added to the list," he said. "These ants play a central role in preventing animals that want to eat trees from doing extensive damage to those trees."
"We found the elephants like to eat the "ant plant" trees just as much as they like to eat their favorite tree species, and that when either tree species had ants on them, the elephants avoided those trees like a kid avoids broccoli," he Palmer said.
"An elephant's trunk is a truly remarkable organ, but also appears to be their Achille's heel when it comes to squaring off with an angry ant colony," he said.
"A big issue in east Africa is elephants damaging crops, which is one reason elephants have been harassed and sometimes killed," he said. "There's been a lot of interest in the conservation world about how to minimize the conflict elephants have with humans and particularly how to keep elephants from raiding agricultural fields."
"With more droughts, the extent to which elephants destroy and remove trees may increase and potentially shift the ecosystems back to grasslands," he said.
"These 'ant plants' don't cover just a few hundred acres but are distributed throughout east Africa from southern Sudan all the way over to eastern Zaire and down through the horn of Africa and Tanzania," he said. "So they potentially play a big role in terms of regulating carbon dynamics in these ecosystems."