Fairy Circle

Fairy circles are circular patches of bare ground, typically 2 to 12 meters across, surrounded by a ring of taller grass, found scattered across arid grasslands. The best known examples stretch roughly 2,400 kilometers through the Namib desert from Angola through Namibia into South Africa's Northwestern Cape, and a second population was identified in Western Australia's Pilbara region in 2014, with possible occurrences reported in North Africa, the Middle East, and Madagascar. Their formation is contested: one hypothesis credits sand termites, which some researchers argue create the bare patches and improve soil moisture around their colonies, while a competing hypothesis holds that the circles arise from grasses self-organizing under competition for scarce water, an explanation recent research has emphasized as the one most consistent with field observations. The two known regions may not share a single cause, which has complicated efforts to settle on one unified explanation.