The Daily Item, Sunbury, PA

Technology

March 29, 2013

Africa's 'Fairy Circle' mystery



By Rachel Nuwer

ScienceNOW

Like others who came before him, Norbert Juergens was caught in the spell of fairy circles. These bare patches of ground, often outlined with a fringe of tall grass, pockmark a 2000-kilometer-long strip of desert stretching from Angola to South Africa. Though the formations have confounded scientists for years, Juergens - an ecologist at the University of Hamburg in Germany - thinks that he may be the first to crack the puzzle.

The strange saga of the fairy circles got even stranger last year. That's when Walter Tschinkel, a biologist at Florida State University in Tallahassee, analyzed 4 years of satellite images of the formations in Namibia's NamibRand Nature Reserve. Tschinkel had been intrigued by the circles since first encountering them on a vacation to Africa in 2005. The images revealed that some of the formations arose and others vanished over the 4-year period - the first evidence that they were somehow "alive." Extrapolating from the data, Tschinkel estimated an average "lifespan" of 41 years. But he couldn't figure out what made them. Some suspected that termites were killing the grass from below, but Tschinkel found no evidence that the insects caused fairy circles. Nor did he find anything wrong with the soil itself.

Juergens's search for answers began a year after Tschinkel's. He started traveling throughout Africa in 2006 - including to remote areas in Angola, still reeling from its recent civil war - in search of fairy circles. He became intrigued with the formations after noticing, like Tschinkel, that the mysterious patches seemed to come and go from the landscape. He recorded any signs of animal life that he came across in and around the circles, such as tracks, dung, or nests. He also dug trenches from the center of the circles to the outside in order to find any subterranean organisms that may be lurking below.

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