Tiniest creatures defend trees

GAINSVILLE, Fla., Sept. 2 (UPI) -- Researchers say one of Africa's smallest creatures -- the ant -- is up to the job of protecting trees from one of the continent's largest animals -- elephants.

University of Florida biology Professor Todd Palmer says hordes of angry ants will crawl up into elephant trunks to repel the ravenous pachyderms from devouring tree cover throughout drought-plagued East African savannas, a university release says.

"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."

Rainfall, soil nutrients, plant-eating herbivores and fire are the main regulators of the mixture of trees and grasses that make up savanna ecosystems, he said.

"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."

Conducting research in the central highlands of Kenya, Palmer said he noticed elephants rarely ate a widespread tree species known as Acacia drepanolobium where guardian ants aggressively swarm anything that touches the trees.

But they would feed on other trees that did not harbor these ants, he said.

When it came to tree species that had ants on them, "the elephants avoided those trees like a kid avoids broccoli," Palmer said.