Quote: A species of acacia tree found in Eastern Africa seems to be protected from elephant damage - by the ants that live on it.
Researchers from the Universities of Wyoming and Florida, in the US, carried out a series of studies in Laikipia District in Central Kenya, and Tsavo National Park, also in Kenya.
Tree cover was decreasing while elephant numbers were increasing. Tree cover stayed the same where elephants were excluded using a high electric fence that other animals can cross.
Elephants are very effective at stripping trees' bark and destroying them while feeding. "The number of elephants in the central highlands of Kenya has become high enough in recent years that we see severely elephant-damaged trees all over the place these days," said study author Todd Palmer.
The researchers were intrigued though when they noticed that tree cover had only decreased in areas with sandy soil - not those with clay soil.
Professor Palmer, together with Jake Goheen, who are publishing their results in the journal Current Biology, noticed that on the clay soil there seemed to be only one kind of tree - an acacia called Acacia drepanolobium. In other areas with sandy soil, there was a much wider range of tree types. | 
