Have Scientists Solved the Mystery of Fairy Circles?

ENVIRONMENT

Mysterious fairy circles have long lured mystics and conspiracy theorists to Africa’s Namib Desert. Now, scientists may have cracked the fairy code. (Washington Post)

Watch our cool video (and standards-aligned study guide) to learn more about this “desert created by water.”

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit, including today’s MapMaker Interactive map.

Fairy circles are the telltale rings dotting this oddball natural landscape in the arid grasslands bordering the Namib Desert. Photograph by Stephan Getzin, courtesy Wikimedia. CC-BY-SA-3.0

Fairy circles are the telltale rings that dot the oddball natural landscape in the arid grasslands bordering the Namib Desert.
Photograph by Stephan Getzin, courtesy Wikimedia. CC-BY-SA-3.0

This fairy circle remains after a fire charred the surrounding vegetation. We like this photo because the firemen in the background give the fairy circle some scale—you can tell how big it is.  Photograph by Vernon Swanepoel, courtesy Flickr. CC-BY-2.0

Here, a fairy circle remains after a fire charred the surrounding vegetation. We like this photo because the firemen in the background give the fairy circle some scale—you can tell how big it is.
Photograph by Vernon Swanepoel, courtesy Flickr. CC-BY-2.0

Discussion Ideas

  • New research suggests an ecological explanation for fairy circles. What are fairy circles?
    • Fairy circles are circular patches of bare ground that appear in arid grasslands. Each fairy circle is about a 3.6 meters (12 feet) in diameter and about 9 meters (30 feet) from the next fairy circle.

 

Fairies are apparently indigenous to the Southern Hemisphere.

Fairies are apparently indigenous to the Southern Hemisphere.

  • Scientists and conspiracy theorists from all over the world have known about fairy circles for a long time, and local Himba scientists and theorists have known about them even longer. What prompted this new research? Look at today’s MapMaker Interactive map for some help.
    • The circles showed up in a new place. For a long time, scientists thought fairy circles only appeared in the Namib Desert of southwestern Africa. (Learn more about the Namib here.) New research also incorporates studies of fairy circles in Western Australia, which were unknown outside the local area, called the Pilbara, until recently.

 

  • What are leading theories about how fairy circles form?
    • Supernatural explanations include extraterrestrial activity, dragons, and giants.
    • Some scientists think sand termites might be responsible. “Living grass sucks up rainfall and loses the liquid to evaporation. But when termites cluster together, feeding on and destroying vegetation, they leave a roughly circular bare patch that stores more water than the surrounding soil. The fairy circle thus acts as a water reservoir for the sand termites, the grasses around the edge and other thirsty organisms.”
    • Some scientists think plants themselves may “self-organize” in the peculiar formation in order to conserve water.

 

  • What theory does the new research support?
    • New evidence based on both Namib and Pilbara fairy circles supports the theory of botanical self-organization. “In a desert environment where water is scarce, the land can only sustain so much vegetation. Attempting to carpet the entire earth with grass would be a recipe for mutually assured destruction, so instead the plants organize into clumps. Covered areas soak up the water from bare areas, and everyone drinks, even when it’s been months since the last rainfall. That’s how the area around the fairy circles can sustain full-time vegetation when the rest of the Namib desert is desolate except for right after a rain.”

 

  • How are Australia’s fairy circles an example of an amazing, healthy desert ecosystem—of living and non-living things interacting in a specific environment?
    • Fairy circles are a desert phenomenon involving precipitation and geology (non-living characteristics) and plants (living characteristic).
      • After a rain, the scant water is pulled in all directions by the Australian desert’s thirsty plants. Depending on how those plants are distributed, some spots inevitably become drier than others. Nothing grows there, so the clay becomes hard and impermeable. And the next time rain falls, it skims over the surface of the crusty clay until it reaches an area where plants are growing. Those plants soak it up, then put down bigger roots, so that when the next rain comes they’re able to pull it away from their neighbors—killing them off and making the bare spot even bigger.”

 

  • Does the new research finally solve the mystery of fairy circles?
    • No! As scientists constantly remind us, correlation is not causation. “It will take an experiment in which scientists artificially create the circles by manipulating water and soil to truly prove the self-organization theory.”

 

 

TEACHERS’ TOOLKIT

Washington Post: Dragons, aliens, bugs? Scientists may have solved the mystery of the desert’s ‘fairy circles’

Nat Geo: Where Can You Find Fairy Circles? MapMaker Interactive map

Nat Geo: A Desert Created by Water video study guide

(extra credit!) Proceedings of the National Academy of Sciences: Discovery of fairy circles in Australia supports self-organization theory (paywall)

One response to “Have Scientists Solved the Mystery of Fairy Circles?

  1. Pingback: What Did You Read in 2017? | Nat Geo Education Blog·

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