NamibRand Nature Reserve, Namibia, Southern Africa is the world’s most ancient desert. This barren grassland is dotted with peculiar circular blotches of red sand with no grass, unlike its surroundings. These circular blotches are fondly known as ‘Fairy Circles’! But what causes these ‘Fairy Circles’ to appear?
These circles are more than 300 million in number and extend for over 1200 miles, from Angola to South Africa via Namibia. These circles vary in size, their average diameter being between 58-60m. However, these circles aren’t as fairylike as they seem. Any plants growing here, wilt and perish, leaving them as bare patches of soil.
A theory was brought by Dr. Mike Picker, an insect expert. He thought that there would be animals living beneath the soil as the circles were evenly spaced, however, there were no holes for subterranean animals to go inside the ground. On observation, it was found that ant-eaters such as bat-eared wolves frequently enter the fairy circles. This suggested that ants may be living beneath the surface. In order to test this theory, Dr. Mike tried an experiment. He put pitfall traps; cups of soapy water in the sand, because if there were indeed ants living underneath, they would fall into these cups and would be unable to escape. As a result of this experiment, 50,000- 80,000 ants were found. After blasting off the sand, he found millions of ants residing beneath the fairy circles, the black pugnacious ant being the most common. Territorial ant colonies explain the even-spacing of these circles.
Prof. Nigel Franks from England believes that the bare patches of soil occur because of a symbiotic relationship between ants and bugs. The bugs suck the honeydew; fluids which are high in sugar off the plant and the ants get this honeydew from the bugs, in return the ants provide the bugs with protection. Too many bugs cause the plant to completely drain out of fluid, thus resulting in their demise.
Dr. Yvette Naude did some more research, during which she found more than 2000 compounds in the soil, out of which, two chemicals- Phytane and Pristane, caught her eye.
Prof. Rich Pancost is certain that the existence of these chemicals confirms the presence of crude oil. Off Namibia’s coastline, deposits of oil and gas have been found. The crude oil is pushed sideways by rocks and on reaching the sandy surface, they spread out into a circular pattern, causing the grass to die and leaving barren patches of soil.
Two contradicting theories, one mystery!
'Fairy Circles'
Comentários