Photo Gallery 

Text ©2013 by J. Pint; Photos
© by J. Pint unless otherwise indicated

 Mahmoud Al-Shanti with guanomite

Geologist Mahmoud Al-Shanti with one of the tallest guanomites in Ghostly Cave.

Daniel Haag-Wackernagel

Daniel Haag-Wackernagel of Basel University, author of  numerous publications on pigeons and rock doves, measuring a "home-grown" guanomite.

Entrance to Ghostly Cave

The floor of Ghostly Cave lies seven meters below this entrance collapse.

x A. Lopez

Spanish chemist Felix A. Lopez working on guanomites.

vine-covered guanomites

Vine-covered guanomites, composed of rock-dove feces.

Guanomite on Malaga cathedral statue

Guanomite growing on a statue at the cathedral of Malaga.

Underground in Arabia by John Pint

The discovery of the Ghostly-Cave Guanomites is narrated in Underground in Arabia by John Pint

Studying towers of guano made by Rock Doves

Guanomites at Ghostly Cave, Saudi ArabiaA few years ago, John Pint, an experienced speleologist working for the Saudi Geological Survey, lowered himself into a lava tube known as the Ghostly Cave in the Harrat Kishb, a barren desert region in the central Arabian Peninsula, and became the discoverer of a new biogeological phenomenon.  Before him lay a field of ‘stalagmites’, some as tall as a man, that were in fact towers made of guano.  Rock doves (Columba livia) use the roof of the cave as a roost and nesting site, and over the years their accumulating droppings formed the structures that John gave the name of guanomites.

Rock-dove guanomites inside Ghostly Cave

A few of 50 or so guanomites inside Ghostly Cave. Note the remains of an old rock wall in the background.

No-one knows anything about them.  How old are they?  How long do they take to form – tens or hundreds of years?  Have they become mineralised?  Are they porous?  How compact are they?  Do they contain pollen grains or traces of vegetation that might give an idea of what the birds fed on?  If they do contain such items, what does that tell us about where the birds fed and how far they fly to find food (there is none nearby)?  What can the contents and mineralogy of guanomites tell us about bygone climatic conditions?

An informal collaboration – The Guanomite Group - between scientists, cave explorers and communicators across four countries is now trying to answer these questions. 

  • John Pint  - speleologist and discoverer of guanomites (Mexico)
  • Felix López – chemist, Spanish Council for Scientific Research (CSIC) (Spain)
  • Eduardo Barrón – palynologist/botanist, Geomining Institute of Spain (Spain)
  • Rafael López – geologist, mineralogist, Geomining Institute of Spain (Spain)
  • Daniel Haag-Wackernagel, pigeon ecologist, University of Basel (Switzerland)
  • Sigurjon Jonsson – geophysicist, King Abdullah University of Science and Technology (Saudi Arabia)
  • Adrian Burton – biologist, science writer and editor (Spain)

Adrian BurtonIf you think your experience can help us, please contact us at and, of course, you are welcome to join G2R.

Watch this space for information on these intriguing structures as our work progresses.

Literature available

1 Roobol MJ,. Pint J.J,. Al-Shanti M.A,. Al-Juaid A.J,. Al-Amoudi S.A, and Pint S. 2002. Preliminary survey for lava-tube caves on Harrat Kishb, Kingdom Of Saudi Arabia, Suadi Geological Survey, Open-File Report SGS-OF 2002-2003.  Available here

2. Jennings MC. 2008. Birds in caves. Phoenix 24: 13-14 [Contact Warners Farm Ho., Warners Drove, Somersham, Cambs PE28 3WD, UK.]

3. Burton A. 2012. Goblins of the Harrat Kishb. Frontiers in Ecology and the Environment 10: 452–452. 

Human and Guanomite silhouettes

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