Kingdom of the tree slug

Although Chris du Feu found fame this Springwatch through his love for the tree slug, he has also been an incredible asset to BTO’s Nest Record Scheme. He reflects on 40 years of volunteering.

The ink was barely dry on my trainee ringing permit when I had a call from John McMeeking (then chairman of the ringing committee) inviting me to come to his ringing operation in nearby Treswell Wood. John had begun what was to become the longest-running throughout-the-year standard site operation in the country. He was keen to make the work not just about metal on legs but to use the data to study the birds in that ancient woodland and to integrate information from ringing with other work in the wood which, at that time included bird territory mapping and coppice management. Coppiced woodland suffers a relative shortage of mature trees with holes for nesting tits and John wanted to initiate a nestbox programme. He detected my interest, dangled the bait and I found myself running a nestbox operation, now in its 40th year.

After a while I realised the BTO nestboxes guide was somewhat out of date and foolishly mentioned this to one of the staff. Over the next 30 years, I found myself editing the next three editions. Nestboxes also brought me face-to-face with the Tree Slug, Lehmannia marginata. This, in turn, led to an additional amateur career in limacology – the BBC Springwatch appearance was, both literally and metaphorically, a high spot. The work with slugs has shown the importance of biological recording particularly for less-studied groups – there are far fewer limacologists than ornithologists.

My ringing career coincided with the arrival of microcomputers. Computer programming had been part of my mathematics degree course so it was natural to apply this to dealing with ringing data. Computerisation of the Treswell Wood data began rapidly. The BTO then appealed for volunteers to develop a suite of software for ringers using the BBC Microcomputer. This was too much to resist – my serious involvement lasted until the arrival of Windows-based PCs and the demise of the BBC microcomputer. The ‘B-RING@’ team laid the foundations for computerisation of ringing data and the coding scheme we developed in the 1980s, although now somewhat enhanced, remains at its core fundamentally the same. The BTO has a long memory. Shortly after my early retirement from teaching I was asked if I would manage the EURING Data Bank - ‘just what you have done before but with bigger data sets’ I was told. After 12 years of one day a week work I have now passed the EDB to a new manager, leaving it in far batter state than when I found it. In return it has left me with good friends and all European ringing schemes.

The data from Treswell Wood now includes nest records, constant effort and other ringing data, breeding territory mapping, coppice age data and more casual records of other species. Data are computerised so we have a comprehensive, accessible data set. Between members of the group and with input from various academics, we have published a variety of papers and also contributed data to various country-wide or pan-European studies. We also have various university students using our data in project work. All these things have involved many contacts with experts, both amateur and professional. I have almost invariably found advice, help and interest readily forthcoming.

My involvement in ringing has revealed many tempting opportunities with potentially exciting prospects. There are problems, though. First is that of time, particularly if you are still burdened by the curse of work. It is not possible to engage in all these different futures – far better to do a little well than a lot badly. The second problem is that these opportunities do not come without cost – they require a great deal of time and effort. We are told in St. Paul’s letter to the Galations that ‘As a man sows, so shall he reap.’ This does not do justice to reality. Put in the effort and the rewards in will far, far outweigh the effort.

Find out more about BTO's Nest Recording Scheme.