Mysterious fairy circles demystified: it's termites (Update)

Mar 28, 2013
Numerous tracks of Oryx antelopes crossing fairy circles in an interdune pan. Aerial view of Namibrand, Namibia. Credit: N. Juergens

They appear in the desert in southwest Africa and persist for decades: so-called fairy circles, or puzzling rings of grass with a barren center.

Now a new study, published Thursday in the US journal Science, purports to end the enigma and explain just what is going on: it's the work of termites.

The fairy circles, which can stretch up to around 50 feet (15 meters) in diameter, are especially common in Namibia, where the indigenous Himba people attribute them to .

Among scientists, the termite theory had been proposed previously but put aside for a lack of evidence.

But botanist Norbert Juergens of Germany's University of Hamburg plunged into the investigation and has offered convincing evidence that the behind fairy circles are likely a particular termite species called Psammotermes.

A fully developed fairy circle with a green perennial belt (living grass plants) and a yellowish matrix (dead short-lived plants), both formed by the same species of grass (Stipagrostis ciliate). Farm Dieprivier / Namib Desert Lodge, Namibia. Credit: N. Juergens

By studying a strip of desert 1,200 miles (2,000 kilometers) long, stretching from mid-Angola down to northern South Africa, Juergens determined that these termites were the only organisms consistently present when the circles were in the earliest stages of forming.

The researcher observed that the termites feed off the roots of perennial grasses, effectively wiping out the plant life nearby.

But the bare patch is then able to hold on to moisture better, because the is not used and evaporated by plants. That helps the termites—and the vegetation around the edge of the circle—thrive, even during the dry season.

The result is an ecosystem, engineered by , transformed from a desert into a , Juergens explained.

Explore further: Warning coloration paved the way for louder, more complex calls in certain species of poisonous frogs

More information: "The Biological Underpinnings of Namib Desert Fairy Circles," by N. Juergens, Science, 2013.

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User comments : 5

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Sean_W
1.6 / 5 (7) Mar 28, 2013
Magic fairyland termites or the regular kind?
PhyOrgSux
1 / 5 (3) Mar 28, 2013
"divine intervention"...wow the difference between knowledge and ignorance...
betterexists
1 / 5 (2) Mar 29, 2013
"Icy-Zhit Garbage Endurance Tactics" Syndromé
tadchem
not rated yet Mar 29, 2013
"Juergens determined that these termites were the only organisms consistently present when the circles were in the earliest stages of forming."
Well, that satisfies one and one-half of Koch's Postulates (#2 and half of #1). Two and a half to go:
(1B) Is Psammotermes always missing from Stipagrostis grasslands lacking the circles?
(3) Does introducing Psammotermes to Stipagrostis grasslands lacking the circles result in circle formation?
(4) Is Psammotermes isolated from artificially induced circles (in #3) genetically identical to the sample introduced?
Three "Yes" answers buys you a confirmation of the hypothesis.
Torbjorn_Larsson_OM
5 / 5 (1) Mar 31, 2013
Well, according to the article biologists are already convinced, i.e. it is already an observation. But Koch's postulates, used in medicine, could take the observation further.