The Scottish Squirrel Database

Quality Control

The data has been updated and maintained since 1997. A recent review of the data has cleaned and removed a large number of duplicates from the dataset. Data is considered of reasonable quality, with verification having been carried out by Saving Scotland’s Red Squirrel Project Officers within their project areas, the Project Manager and/or organisations submitting data (as described in Methods). Data validation procedures have also been undertaken, including use of the automated validation checks in NBN Record Cleaner. Whilst the data has been checked as carefully as possible, maintenance and quality control is an ongoing process.

Method steps

1. Multiple methodologies, including: sightings (public and casual, including web recording forms); grey squirrel control; transects (sightings and cones); feeding signs; hair-trap boxes; museum records. Records were submitted directly to the Scottish Squirrel Database, or supplied via Local Record Centres, squirrel groups or other bodies. This uploaded dataset includes all verified records submitted to the date of upload. The validity of recent records, those submitted directly to the Scottish Squirrel Database (such as through online submission) and data generated by the Saving Scotland’s Red Squirrels project (SSRS) has been manually assessed by SSRS regional project officers or project manager, using their expert knowledge. Where data originates from other organisation’s databases, initial verification and validation was undertaken by the supplier in accordance with their own procedures, with some further verification as above. Broad validation checks have been undertaken by Scottish Wildlife Trust staff in recent years during preparation of data for inclusion in the database, including mapping records geographically to identify clearly erroneous locations. The automated validation checks of NBN Record Cleaner have also been utilised.

The geographical coverage is Scotland; a few casual sightings from other parts of the UK may be included. Recording effort is not standardised spatially. Coverage will reflect the many casual sightings, which are biased towards populated areas. Records generated through Saving Scotland’s Red Squirrels project, such as through surveys and project based grey squirrel control, will be concentrated in the areas of project activity: Argyll & Trossachs, Tayside and North East and South Scotland. Coverage may also be influenced by the presence of other organisations involved in data collation who submit records to the Scottish Squirrel Database (such as Local Records Centres), reflecting increased resource available in these areas to mobilise data, for example. The majority of the records are recorded at 100m grid references. Where the records have been generated from trapping results they have been given 1000m grid references as the locations may be sensitive.