Mysterious Fairy Circles in Africa Not Caused by Hungry Termites

It turns out that the mysterious "fairy circles" in Africa may not be caused by termites after all, despite previous research. Scientists have instead discovered that the strange rings that can be found in African grasslands may be caused by plants in the region.

These "fairy circles" in certain parts of southwest Africa are barren, circular patches. Some only measure a few feet, while others can reach up to 65 feet in diameter. Most of them sport a lush peripheral growth of grass, despite the barren circle in the middle. However, scientists have been unable to explain what causes these circles to form.

There are, though, several theories that explain these circles. One of them states that these circles are the work of termites, which nibble away at grassroots and eventually cause the circle to form. Others believe that hydrocarbons emanating from the depths of the earth could be responsible. Still others believe that self-regulating grass growth in itself may be to blame. Now, scientists have examined all three of these hypotheses and found the most plausible explanation.

The scientists reviewed and evaluated aerial images of the fairy circles, covering regions throughout northwest Namibia. The researchers analyzed the exact spatial location and distribution of these circles within the surrounding landscape, determining how they were arranged and positioned. Surprisingly, the scientists found that the fairy circles are distributed surprisingly regular and homogenous, even across large spatial areas.

"The occurrence of such patterning in nature is rather unusual," said Stephan Getzin, one of the researchers, in a news release. "There must be particularly strong regulating forces at work."

This patterning actually discredits the termite theory. Currently, there's no proof that shows these insects are capable of creating homogenously distributed structures on such a large scale. Instead, it's likely that resource-competition among plants and vegetation could be to blame.

For example, in a young-growth forest, plants will grow and develop at a comparatively close range. Then vegetation will thin out and regress over the years in a self-organizing process. A similar process of resource-competition could be the cause of these fairy circles.

The findings are published in the journal Ecography.