Wednesday 21 May 2014

Snails prove a fascination

I can remember being fascinated by snails as a child. Our garden seemed to abound with them and it was the large garden snails, Helix aspersa, which most often held my attention. I could spend hours watching as each emerged from its shell, extruded a grey tube of body and then inverted the pair of curious eye stalks; the latter behaviour still fascinates me to today.

Although widespread across a host of habitats in the south of its European range, Helix aspersa becomes more closely associated with gardens as you move north. Its size, coupled with the patterning on the shell, makes it pretty much unmistakable. There is a related species, Helix pomatia, larger in size and with less complex patterning on the shell, with which it might just be confused. Helix pomatia is restricted to a few chalky areas in the south of Britain where its presence is the result of ancient introductions, the snail providing a source of food for the supper table. Its populations, which had been threatened by entrepreneurial wild foragers, are now protected by the Wildlife and Countryside Act.

My childhood interest in garden snails, much like my wider interest in natural history, was stimulated by books written to encourage young naturalists. Each was packed with ideas for experiments or other activities and I can recall marking the shells of our snails with paint to see how individuals moved between different parts of the garden. I might even have used this approach to calculate the size of the snail population in different parts of the garden through a simple ‘mark-recapture’ calculation. Such calculations, though more complex in form, were a staple of my university fieldwork on small mammals many years later.

Garden snails are so accessible that I would hope that today’s generation of children still gets to ‘play’ with them and to learn about natural history and to respect the other creatures with which we share our gardens. Mature garden snails are robust creatures, well able to cope with the curiosity of youthful fingers. Importantly, they are also fun, particularly when blowing bubbles or rolling out their eyes. What child could fail to be impressed and educated by snails, hopefully carrying that childhood impression with them into adulthood.


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