tag:blogger.com,1999:blog-4912713243046142041.post4994487348765415138..comments2024-03-28T23:22:41.774-05:00Comments on TYWKIWDBI ("Tai-Wiki-Widbee"): "Fairy circles" in the Namibian desert - updatedMinnesotastanhttp://www.blogger.com/profile/01382888179579245181noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-4912713243046142041.post-40954535048129582412013-04-02T11:47:34.417-05:002013-04-02T11:47:34.417-05:00The third photo kind of reminds me of the ice circ...The third photo kind of reminds me of the ice circles that I saw in Lake Michigan this winter.Stevehttps://www.blogger.com/profile/10619153370091469672noreply@blogger.comtag:blogger.com,1999:blog-4912713243046142041.post-62842546091749412212013-04-01T15:22:25.150-05:002013-04-01T15:22:25.150-05:00I saw that story via the BBC this week -
http://w...I saw that story via the BBC this week -<br /><br />http://www.bbc.co.uk/news/science-environment-21970408<br /><br />- but then to my frustration couldn't find this old post via the search engine. Thanks for your note; now I can post an update.Minnesotastanhttps://www.blogger.com/profile/01382888179579245181noreply@blogger.comtag:blogger.com,1999:blog-4912713243046142041.post-83850841120774275842013-04-01T14:38:35.418-05:002013-04-01T14:38:35.418-05:00This article is at New Scientist. http://www.newsc...This article is at New Scientist. http://www.newscientist.com/article/dn23331-termites-are-the-fairies-behind-weird-desert-rings.html<br /><br />It postulates that a particular species of termite is associated with these circles, including photographic evidence showing these termites being found living among the roots of the grass they eat.W_D_Richardshttps://www.blogger.com/profile/12841283259590535613noreply@blogger.comtag:blogger.com,1999:blog-4912713243046142041.post-24623293930209364192012-11-13T07:46:48.146-06:002012-11-13T07:46:48.146-06:00Although... while searching for the etymology of t...Although... while searching for the etymology of the interesting word "heuweltjie," I have seen some photos of barren spots, so perhaps the word has various meanings or applications.<br /><br />(Still haven't found the etymology. Probably Dutch.)Minnesotastanhttps://www.blogger.com/profile/01382888179579245181noreply@blogger.comtag:blogger.com,1999:blog-4912713243046142041.post-90228305361567049652012-11-13T07:41:42.313-06:002012-11-13T07:41:42.313-06:00He does comment on the termite hypothesis as follo...He does comment on the termite hypothesis as follows:<br /><br />Several authors [1], [3], [4], [7], [8], [9] proposed some version of causation by termites either through direct action, residual effect or emission of a toxic agent. However, Tschinkel [10] found no association between the nests or underground foraging tunnels of the endemic termite Baucaliotermes hainseii and fairy circles, nor have other termite species been found to be associated with fairy circles [2], [9].<br /><br />and -<br /><br />The termite hypothesis of Albrecht et al. [1] would require that the termitaria deep underground be spaced in patterns like those of the circles above them. In principle, termite colonies have the capacity to be overdispersed, but unfortunately even the existence of such termitaria, let alone their spatial distribution is unknown. Moreover, Tschinkel [10] found no association between termite nests or foraging tunnels and fairy circles.<br /><br />Albrecht's hypothesis apparently involved harvesting water:<br /><br />Albrecht et al. [1] (2001) report that 12 days after rains, circle soil contained more water than matrix soil (but this was unreplicated, as well as a single sample point in time) and suggested that the circles act as “water traps” to benefit subterranean termites.<br /><br />I looked up "heuweltjies", and they seem to be described as "mounds" both in Wikipedia -<br /><br />Heuweltjies are fossil termite mounds occurring widely in the south-western Cape of South Africa. Heuweltjies can sometimes be recognised as large mounds above or near the surface of the landscape. There are two conflicting interpretations as to the origins of heuweltjies, the one view maintaining that heuweltjies were built by the harvester termite Microhodotermes viator while other researchers maintain that heuweltjies were built by a now possibly extinct termite species.[1] The earliest radiocarbon dates on heuweltjies date to about 30,000 B.P.<br /><br />- and in your first link:<br /><br />Heuweltjies are large circular earth mounds created by termites and are important features of the landscape in the Succulent Karoo biome in South Africa<br /><br />And also in the Quaternary Research article. So perhaps those are different entities from the fairy circles discussed here?Minnesotastanhttps://www.blogger.com/profile/01382888179579245181noreply@blogger.comtag:blogger.com,1999:blog-4912713243046142041.post-35720699562190633932012-11-13T00:49:53.703-06:002012-11-13T00:49:53.703-06:00Common known as 'heuveltjies' here in sout...Common known as 'heuveltjies' here in southern Africa, they're a common feature of the arid western regions, almost certainly caused by termite activity. I had a look at the PLOS article, and although it's interesting and detailed work, I'm not sure why the author thinks the "causes of these so-called “fairy circles” are unknown". Actually, reading deeper in the comments, I notice he says " I did not delve deeply into causes because my purpose was to describe the variation of circles, to sequence the life cycle and to estimate the life span." Ah, the benefits of peer review :)<br /><br />The image at the top is a great one, though, and the science of heveltjies is fascinating. For those wanting to read deeper, there are a lot of published journal articles:<br />http://www.sciencedirect.com/science/article/pii/S0140196312001632#<br />http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2006.00189.x/pdf<br />http://web.uct.ac.za/depts/geolsci/downloads/Potts_etal_09.pdf<br />Hallam Paynenoreply@blogger.comtag:blogger.com,1999:blog-4912713243046142041.post-89670563891857572332012-11-12T23:52:41.578-06:002012-11-12T23:52:41.578-06:00I have seen similar evenly-spaced bare patches in ...I have seen similar evenly-spaced bare patches in the deserts of eastern Oregon. The ones here are obviously caused by ants. I doubt they missed something so obvious.Dougohttps://www.blogger.com/profile/16439779634103149937noreply@blogger.comtag:blogger.com,1999:blog-4912713243046142041.post-84429535025456605292012-11-12T15:12:47.391-06:002012-11-12T15:12:47.391-06:00The answer to your question is in the link...
The answer to your question is in the link...<br />Minnesotastanhttps://www.blogger.com/profile/01382888179579245181noreply@blogger.comtag:blogger.com,1999:blog-4912713243046142041.post-26302014377208073082012-11-12T14:54:31.159-06:002012-11-12T14:54:31.159-06:00Strange... They do have a distinct 'petri-plat...Strange... They do have a distinct 'petri-plate' look to them, kind of like phages spread on a lawn of bacteria. Do they appear suddenly, or do the patches 'grow'?Anonymousnoreply@blogger.com