Autumn is here, and it’s time to see how the ditch trials at RSPB’s Pulborough Brooks reserve are doing. It’s been fabulous to be able to explore these waterways that are normally not accessible to the general public. The trials have involved trying different ways of managing the ditches to see which variation works best for this rare and localised snail.

The surveying for this tiny snail involves sweeping a net a standard number of times through the vegetation in the ditch, rinsing the contents into a tray and seeing what’s in the bottom. By looking closely in the tray (with my ‘head eyes’ – special magnifying goggles made for jewelers but equally good for looking at small invertebrates) we’ve been able to identify this snail whilst out in the field, count them and then release them back into the ditch unharmed. The majority of the snails have been tiny juveniles often little larger than a millimeter across. The adults are large at up to 5mm across.


Toby Abrehart sampling snails,RSPB Pulborough Brooks. Photo - Jane Sears.


One of the great things about Pulborough Brooks is that it supports not only the rare snails, which include the wonderfully named ‘Large Mouthed Valve Snail’ (Valvata macrostoma) but all the other invertebrates too. These include the largest beetle in the UK, the Great Silver Water Beetle (Hydrophilus piceus) and numerous other species. We also found plentiful quantities of the Critically Endangered Sharp-leaved Pondweed, Potamogeton acutifolius.

These surveys found that the snail was doing really well in many of the ditches and preferred certain methods of clearance, which is great to see.

Whilst we were out doing the work, a contractor was still digging the new spurs leading from the dykes to create more habitat. A quick look at the vegetation here showed that some Little Whirlpool Ramshorn Snails had already moved in, probably swept in on the floating vegetation as the water flowed in.


 Photographers. Photo -  Abrehart Ecology.


In addition to all the surveying fun, we had the Back from the Brink photographers down to document our activities which was entertaining and not at all distracting, even when they clambered on the roof of our car to get the best view of our 5mm snail. Never have us surveyors been so captured on film!


 "Car pose". Photo - Abrehart Ecology.


But the whole survey has started to show good results and we look forward to coming back to see what’s happening next year.


Toby Abrehart

Snail Surveyor!
Little Whirlpool Ramshorn Snail.



Would you like to help these incredible species? There are numerous ways in which you can:

  • Why not volunteer for Back from the Brink? Check out our events page for opportunities near you.
  • Help us to spread the word of this species, and the others we will be helping over the next 3 years, by sharing our message across our Twitter, Facebook, Instagram and YouTube pages. Follow us: @naturebftb.
  • Finally - help support the work we do across England by donating. Our impact will be greater with your help.