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Are snails too slow for their own good?

19 September 2007

Snails are not known for their high speed, but like all animals they must move around to find food, mates and suitable places to live.

Now, ecologists at Cardiff University have shown how the inability of some endangered snails to spread between locations is seriously affecting their survival in Britain.

The Shining ram’s horn, the Little whirlpool ram’s horn and the Large-mouthed valve snail are three of Europe’s rarest snails, and live in drainage ditches on wet grasslands. Smaller than a little-finger nail, all three have declined dramatically over recent decades as their habitat has been lost, damaged or polluted.

Working on several protected marshlands in south-eastern England, including Pevensey Levels and the Arun Valley, the researchers found unexpected gaps in the snails’ range that were more frequent at larger distances from occupied sites. Even the most desirable snail locations were sometimes unoccupied.

Professor Steve Ormerod, of Cardiff University’s School of Biosciences, who led the work, described the finding as a "critical breakthrough in snail conservation."

"We knew already the snails were affected by being fussy about certain conditions, and by problems in wetland management. This new work shows that dispersal between remaining habitats is also a major constraint: these snails now need help to get around," he said.

Dr Isabelle Durance, also a member of the Cardiff team, added: "Natural habitats increasingly form a tattered and changing patchwork, and animals must reach habitats in which they can survive. With their snail-paced movement in a fast-changing world, these species epitomise a larger conservation problem."

Notes to Editors:

1. A paper on the team’s research, Applying landscape ecology to conservation biology: spatially explicit analysis reveals dispersal limits on threatened wetland gastropods, by Karla Niggebrugge, Isabelle Durance, Alisa M Watson, Rob S.E.W. Leuven and S.J Ormerod is published in the current issue of the journal Biological Conservation (2007; Vol 139, 286-296).

2. The Shining ram’s horn (Segmentina nitida), the Little whirlpool ram’s horn (Anisus vorticulus) and the Large-mouthed valve snail (Valvata macrostoma) are all listed in the UK Red Data Book of threatened species. Anisus vorticulus has been listed in Annex II of the EU Habitats Directive since 2003 (92/43/EEC).

3. The work was carried out on the the Arun Valley in West Sussex, Pevensey Levels in East Sussex, the Stour Valley in Kent, and Lewes Brooks in East Sussex

4.Cardiff University is recognised in independent government assessments as one of Britain’s leading teaching and research universities. Founded by Royal Charter in 1883, the University today combines impressive modern facilities and a dynamic approach to teaching and research. The University’s breadth of expertise in research and research-led teaching encompasses: the humanities; the natural, physical, health, life and social sciences; engineering and technology; preparation for a wide range of professions; and a longstanding commitment to lifelong learning. Cardiff is a member of the Russell Group of the UK’s leading research universities. Visit the University website at:

Further Information:

For more information, please contact:

Professor Steve Ormerod
School of Biosciences
Cardiff University
02920 875871

Stephen Rouse
Public Relations Office
Cardiff University
02920 875596