Data Diaries #4 - Tansy Beetles in York
Data is at the core of what we do as a Local Environmental Records Centre. This series shines a light on the breadth and variety of the records we receive and how we deal with them.
The Tansy Beetle is one of our most iconic Yorkshire species. Every year, we gratefully receive records from the Tansy Beetle Action Group’s annual transect surveys across York, which aim to understand the plight of the Tansy Beetle and its status in our region. These records reflect a huge volunteer survey effort across the York area.
NEYEDC has been receiving records from the Tansy Beetle Action Group’s work across York since 2010. Formed in 2008, the group initiates and oversee conservation efforts aimed at saving the Tansy Beetle (Chrysolina graminis) from extinction in Britain and is currently working towards a 5-year plan for its conservation. As part of this work, volunteer recorders take responsibility of one or more of 30 set transects each year, walking the set routes and recording the presence or absence of Tansy Beetle, its foodplant Tansy - around which it spends its entire life-cycle - and other incidental findings (such as invasive and non-native species) at different points. In more recent years, survey forms have also given volunteers the opportunity to note the presence and size of Tansy clumps and identify the grazing status of the area in addition to the presence and absence of the beetle itself. These transects extend across York and surrounding areas, mainly following the River Ouse and take in 45 km of river (90 km of bank), stretching from Linton Lock in the north to Selby in the south and covering the entire range of the Yorkshire beetle population. The data returned to NEYEDC each year is comprised of 30 spreadsheets, one for each transect, which contain eastings and northings of different points along the transect from its start to end, and columns to record presence/absence of Tansy Beetle and the additional information mentioned above.
Tansy Beetle (c) Vaughan Grantham, YNU Flickr
Preparing each year’s survey data begins with inspecting each transect spreadsheet and ensuring that data is present for every point indicated along the transect. To begin translating this raw data into NEYEDC’s format, the eastings and northings of each data point are converted to grid references, in line with the rest of the data we hold. Next, the records are mapped in GIS, which serves a dual purpose in the case of these records. Firstly, mapping the records allows us to undertake some of our standard validation checks on location and spatial reference. Mapping the records allows us to visualise where the records are located and, by referencing the name of the transect, we can easily identify records that lie outside of that area or look erroneous, which may point to an error in the eastings and northings in the raw data. If this error is obvious we may be able to change this ourselves in our own formatted version of the records (keeping a record of any changes made) but less obvious errors may need to be queried with the data provider. Mapping also allows us to extract more specific information about each point’s location. NEYEDC provides a ‘Site Name’ or Location alongside all records where possible, but in this case, each set of data points from a single transect is initially only linked to a general transect name (e.g. Linton Lock to Nidd). By mapping the records, we can allocate some more detailed location information to go alongside each data point. The original name of the transect and a link back to the raw data is always maintained, so at any point individual records can always be linked back to their transect. After grid references have been generated and locations confirmed, the rest of the data can be transcribed for each point. Each formatted transect spreadsheet is then combined into a spreadsheet for that year, ready for inclusion in our database.
For clarity, all Tansy Beetle records for that year are added in one module (both positive and negative records) and records of Tansy and additional observations (e.g. INNS species) recorded in a separate module but prepared in a very similar manner to the Tansy Beetle records. Whilst not standard for all datasets, we always report negative records in the case of the Action Group’s records, as this is an important aspect of the record collection methodology and is relevant to allow records to be compared year on year.
Stands of Common Tansy, Tanacetum vulgare
The records provided to us by the Tansy Beetle Action Group are very interesting for us as a records centre. Whilst we do receive other datasets comprised of only single-species, we rarely receive data from structured transect surveys over such a long period of time, and the inclusion of additional information, such as foodplant records alongside the focus species, make these records particularly valuable and a welcome submission each year!
To learn more about the Tansy Beetle in York, you can read Dr Geoff Oxford’s 100 Species blog on the species: https://www.neyedc.org.uk/100-species/2023/7/26/40-tansy-beetle-by-geoff-oxford.