New research shows that "fairy circles," large bare patches that form in a region of southern Africa, likely aren't caused by termites, contradicting an earlier hypothesis and leaving scientists baffled again.
The barren circles of ground that are usually surrounded by thriving plants have been a mystery for decades, and researchers don't seem to be much closer to finding the answer. A recent theory proposed that a species of sand termite often found inhabiting the fairy circles was responsible; however, aerial shots of the unusual formations seem to have debunked that hypothesis, Live Science reported.
While looking at images from the air, scientists noticed that the bare patches, which can be as large as 65 feet in diameter, appear in patterns that are too regular to be the work of random clusters of termites.
"The occurrence of such patterning in nature is rather unusual," study researcher Stephan Getzin, of the Helmholtz Centre for Environmental Research (UFZ) in Leipzig, Germany said in a statement quoted by Live Science. "There must be particularly strong regulating forces at work."
Getzin and the research team say that the termite distribution is too irregular and that the insects couldn't be responsible for such consistent patterns.
"There is, up to now, not one single piece of evidence demonstrating that social insects are capable of creating homogenously distributed structures on such a large scale," Getzin said in a statement quoted by Live Science.
Publishing their findings in the online journal Ecography, the research team compared fairy circles to the way plants grow in a forest since their best theory is that grass grows in fairy circle patterns as it competes for water.
While plants in a young forest tend to grow in proximity to one another, vegetation later thins out as the forest expands to give mature trees enough space and resources. Getzin and his colleagues believe that the fairy circles in the grasslands of Namibia show grass regulating itself in the same way.