Special interest groups ctd

RIGS Group

Delabole Butterfly Few people would connect geology with butterflies, the theme of this Wild Cornwall. After all, the colours of living things are very rarely preserved in fossils and it takes exceptional conditions to preserve insects as delicate as butterflies and moths. But once you consider present-day butterflies, geology does become important, as butterfly distribution depends partly on the appropriate food plant, which of course grows in the soil derived from the underlying rocks. In Cornwall, for instance, brown argus caterpillars feed on cranesbills on the hot coastal sand dunes.

"Delabole Butterfly". Photo: Charlie David

To return to fossils, the 'Delabole Butterfly' is no insect but a deformed fossil shellfish found in the slates around Delabole. The name, no doubt, made them easier to sell to Victorian tourists, just as at Dudley in the Midlands people sold trilobites as 'Dudley Locusts' (which look more like woodlice, but 'Dudley Woodlice' might not have found so ready a market!).
Fast-forwarding a few hundred million years to today, a new sea-defence scheme will cover part of Praa Sands RIGS (temporarily, on a geological time-scale). Peter Ealey and others are surveying the section and recording what the engineers uncover. The results should be published in one or other of the science journals. Peter has a walk there on 3rd August.
In the diary you will find guided walks throughout Cornwall, from Cawsand (volcanics and continental deposits, with Gordon Neighbour), to Carlyon Bay (folds, volcanics, raised beach and fossils, with Colin Bristow), to the Penryn bypass (engineering geology, with Richard Hocking).... not forgetting The Lizard and North Cornwall.
John Macadam

Bat Group
The very cold snap at the end of December has had a marked effect on hibernating bats. There was a redistribution from shallower sites to deeper, warmer ones. Greater horsehoe bats in mine workings on the north coast normally hang about 20 feet from the surface, but the cold weather cleared them all out of the normal places. Several long-eared bats have also been found underground this winter; normally they hibernate in buildings, and these sites were obviously too cold this winter.
Cornwall Bat Group has continued its survey of hibernation sites this winter. The group has also been active in giving advice on barn conversions and has continued its work of advising householders with bat roosts, particularly where remedial timber treatment and building work is needed.
Daniel Eva

More Snippets

So said an advertisement recently in the Western Morning News which invited landowners who wished to bulldoze their hedges to do so while they still could. Why?
Because the Government has just laid regulations before Parliament which would in future offer some limited protection to hedgerows. If a hedgerow qualified under the criteria, landowners would have to notify the local authority and seek permission before they could destroy it.
Sadly for the hedges, the protection to be offered will cover only about one in five hedges in the country, according to the Council for the Protection of Rural England's national assessment. But whether statutorily protected or not, Cornish hedges are a key part of the landscape and have important ecological and historical interest. And they deserve to be watched over.So the Penwith Branch of the CPRE is starting a Hedgerow Action Campaign to log and monitor local hedges. We will start small, by looking at a limited area, and we will want to involve other bodies, schools etc. We would love you to join us in this. If you are interested, please contact our CPRE Hedgerow Co-ordinator, Joan Armstrong, on (01736) 797791. And watch this space!...
Heather Rowe

Water Volewatch
We have large supplies of colourful Water Volewatch leaflets for anyone interested - not just children. The information is interesting, the survey is simple to carry out, and the records it will produce are desperately needed. Please contact HQ for your leaflet(s), and how about joining the Trust's new Mammal Group at the same time?
Mark Nicholson

Ever seen one of these?
Mole cricket
The impressive mole cricket hasn't been recorded in Cornwall since 1920, but I couldn't resist using this photograph (and anyway, you never know....). Researchers working on the Mole Cricket Species Recovery Project would be very glad of any information on sightings from this county or elsewhere. Write to Mole Cricket Survey, PO Box 126, Farnham, Surrey, GU10 3QL.
Mark Nicholson

Mole cricket. Photo by courtesy of Howard Inns

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