Radford Cave, in Hexton Wood, near Hooe, Plymouth,

Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devo ...

is a small

phreatic ''Phreatic'' is a term used in hydrology to refer to aquifers, in speleology to refer to cave passages, and in volcanology to refer to a type of volcanic eruption. Hydrology The term phreatic (the word originates from the Greek , meaning "well" ...

cave of some ecological interest. It has been known to speleologists and others for many years and a plan was published in 1953.

Sport caving

It is a popular place for adventure-seekers and those new caving, since it provides an easy round trip and is it difficult to get lost. However, there are occasional incidents when the inept, over-enthusiastic or inexperienced become stuck. There was, for example, a small drama reported on the front page of the Western Morning Herald, as well as in the Daily Telegraph where a Coldstream Guards instructor became wedged by his hips, face down, and had to be chipped free. The cave is locked to protect the bats.

Physical environment

The cave is situated in an old quarry in Devonian limestone. Its total passage length is around 600m. Cave temperature is 12-13 Celsius. Air moves into the cave during daylight hours and out during the hours of darkness. The maximum passage height is about 9m with humidity varying within the cave from 83 to 98%, but it is usually at the top of the range. Local building may have had an effect on the ecology of the cave. The pools of water within the cave are at a pH of 7.7. Organic matter comprises less than 6% of the cave clay so this is a poor food for invertebrates.

Wildlife

Various zoologists with an interest in cave-dwelling creatures have worked n the cave. Both the

Greater Horseshoe Bat The greater horseshoe bat (''Rhinolophus ferrumequinum'') is an insectivorous bat of the genus '' Rhinolophus''. Its distribution covers Europe, Northern Africa, Central Asia and Eastern Asia. It is the largest of the horseshoe bats in Europe an ...

and the Lesser Horseshoe Bat have been recorded inside. The invertebrates have been documented by various collectors, and records are held by the British Cave Research Association. The isopod ''Androniscus dentiger'' (Trichoniscidae) and acari ''Eugamasus loricatus'' (Parasitidae) are found throughout the dark zone of the cave. The commonest

collembola Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called Ento ...

are the lightly pigmented troglophiles ''Heteromurus nitidus''; the white

troglobite A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves. These are separate from species that mainly live in above-ground habitats but are also able to live u ...

''Pseudosinella dobati'' also inhabits the cave. Both are 1.7mm long. Other Collembola have been recorded including ''Entomobrya muscorum, Schaefferia emucronata, S. lindbergi, Onychiurus armatus, Neelus murinus, Arrhopalites caecus,'' and ''A. pymaegus''.

Collembola Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called Ento ...

are particularly abundant in the Red Corridor section of the cave where humidity is generally at 93-94%. The

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

''Meta menardii'' (shown) inhabits the entrance and threshold zones of the cave and is sometimes found in the dark zone.

References

External links

* photo galler

* a caving tri

* ecology and cave climate pape

* Devon cave ecology pape

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