The Girdled Snail in Hampshire – an interesting mode of dispersal

The Girdled snail (Hygromia cinctella), a rapidly expanding introduced species, is now well established in Alton and other parts of Hampshire. The snail could be reliably found only from the west country until about the 1990s and the beginning of its expansion was captured in the map published in The Atlas of Land and Freshwater Molluscs of Britain and Ireland by Michael Kerney (Harley Books, 1999) (page 193). It was found alive in Flood Meadow, Alton, on 9th April 2006 and has continued to occur in my garden in Ashdell Road, Alton, seen on 1st May 2006. Also in Alton, several live specimens were seen attached to bollards in the car park of Sainsbury’s supermarket on 23rd October 2006. I quickly went home and returned with a camera. This part of the car park is particularly devoid of vegetation for either food or shelter. I presume that the snail originated from the garden and front drive of one of the shoppers and arrived at the car park stuck under a wheel arch. Wet weather and the disturbance of the journey would have brought the snails into activity and exploring the car park. It could be that the shoppers returned before the snails did and with their car habitat gone, they then ascended the bollards. Examination of the car park on subsequent days did not reveal the snails, so they may have been taken by birds, or crushed on the ground. Car park bushes in Fordingbridge provided the first county record of this snail for Hampshire, where they were found by the Rev. Graham Long. Another Hampshire record from a garden in Winchester was made by John Glasgow on 28th August 2006, who brought the living specimens for checking. The Girdled Snail is up to 1cm across and the periphery of the shell has a sharp keel that is marked out in white (See also other articles relating to this snail in previous editions of Mollusc World, e.g. issue 10.22 and 12.21).

Figures 1 and 2: Coming to a supermarket near you. Girdled Snail on posts in the car park of Sainsbury’s, Alton. Photos by June Chatfield

(From the 2006 Annual Report of the Alton Natural History Society)