‘…Through the Action of Worms’

Hand searching for earthworms

Team Earthworm at Powis Castle.  Last weekend Tom.bio welcomed the Earthworm Society of Britain to Preston Montford for their latest Field Meeting. A young and dynamic group, the ESB have done a huge amount of work over the past few years to increase participation in the Earthworm Recording Scheme.

Participants were mixed in both age and experience, ranging from complete earthworm (and invertebrate) novices to those with much more experience and expertise. Ecological professionals mixed with Masters students and those for whom invertebrate work is an interest outside of their academic or professional life. It was lovely to be in such a mixed group and it made for a very welcoming, non-intimidating atmosphere.

Searching compost heaps for earthwormsOn Saturday morning we visited the National Trust’s lovely Powis Castle to sample in their garden compost heaps, grassland and woodland areas (I can also recommend sampling their café!), then returned to Preston Montford in the afternoon to sample in the various habitats around the field centre. We learnt how to do a standardised, five pit sample, and also how to carry out more random, ad-hoc searching. Unfortunately, earthworms are one of those groups for which species level identification requires detailed microscope work on preserved specimens, so we also learnt how to set and preserve the worms for later examination in the lab.

Identification in the classroom. Photo: C.BellSunday saw us based in the classrooms at Preston Montford. The ESB took us through the identification process, which involves closely examining the worm’s head, followed by lots of counting of segments to determine which segments house features such as the saddle (‘clitellum’), the ‘male pore’ and the tubercula pubertatis (TP), all features used in reproduction. Some species also require close examination of the placement of tiny bristles, or setae, on the worm’s body. Examination of these features allows the worm to be identified as one of the 27 British species...in theory, anyway!

I’m willing to bet earthworms are one of the most frequently encountered, and certainly recognisable, invertebrates. They also have immense economic value due to their role in breaking down vegetation and soil particles, aerating soil and allowing valuable nutrients to be released. It’s not too overblown to say that our farming industry would be non-existent without the humble earthworm. Indeed, it isn’t an exaggeration to say that the whole of society depends on the presence and action of earthworms! Given this, it seems strange that they remain an incredibly under-recorded group. We were told it was likely that our weekend’s sampling would generate many county ‘firsts’ for quite a few of the earthworm species. There is still a huge amount we don’t know about their distribution, abundance and habitat preferences.

Charles Darwin recognised the importance of the earthworm; his last published work was 'The Formation of Vegetable Mould, Through the Action of Worms' in 1881 (a bestseller, selling more copies in its day than ‘On the Origin of Species…’). Hats off to the ESB, truly following in Darwin’s footsteps.

Earthworm! Photo: C.BellAs for me, I think I’m hooked! It was my first real venture into the world of worms, and I found it fascinating. The identification, though not easy, is doable – unless the worm is a juvenile or is damaged in some way, the features you need to look for are reasonably straightforward to find. And, at 27 in Britain, the number of different species to get to grips with is manageable. There is also an excellent, very readable AIDGAP key which is suitable for beginners – highly recommended!  Tom.bio have agreed to monitor a meadow site at Preston Montford monthly, so I'll be getting lots of practice.

If you’re interested in learning more about earthworms and contributing to their recording, see the ESB website. Over the next three years Tom.bio will be working with the ESB to promote earthworm recording, deliver training to new earthworm recorders and support existing earthworm recorders to create new records. Bring it on!

ESB President keiron Brown demonstrates earthworm sampling. Photo: C.Bell
Earthworm sampling in the grounds of Preston Montford. Photo: C.Bell