The enigma behind Fairy Circles 

The enigma behind Fairy Circles 

Did You Know

Aerial view of Fairy Circles. Image credit: Stephan Getzin

In the arid grasslands of Namibia, hostile to most life forms, are thousands of circular patches of barren land surrounded by grass. For a long time, no one understood how these circles, each about two to 15 metres in diameter, formed. Hence, they were called ‘Fairy Circles’, attributing their creation to some supernatural powers. The nomadic tribes in the region revered them as footprints of the gods. The folklore also had it that these circles, unique to this region, were created by dragons! Scientists, however, believed none of it and took a closer look at these mysterious circles.

Since the early 2000s, many theories have been proposed about how the Fairy Circles form. One states that toxins from the surviving grass remain in the soil and prevent new plants from growing. Another says that a species of sand termites (Psammotermes allocerus), which live under the desert sand, create these rings by borrowing the soil. 

The most convincing theory so far has been that of the ‘self-engineering’ of grasses leading to these structures’ formation. When the grasslands start to grow, it is homogenous. However, the dry conditions and lack of nutrients in the soil spark an intense competition between the grasses. Those grasses that can suck up all the water and nutrients thrive, while others die, creating the barren landscape. Over time, the empty patches become reservoirs of nutrients, on which the well-established grass feed and the structure stabilises over time. 

In 2014, similar Fairy Circles were discovered in Australia, where the soil is rich in clay. When researchers studied these circles, the evidence seems to support the above theory. They found that the dry, harsh conditions in Australia create a crust of clay, hostile to life, in the barren parts. But, when rainwater runs off the crust, it makes an oasis-like condition on the edges, helping the grass grow. With this finding, they hope to have drawn a curtain on the puzzling Fairy Circles, a natural wonder indeed.