Butterfly distributions for Scotland from Butterfly Conservation and the Biological Records Centre

Quality Control

We have a high degree of confidence in the data and believe that all reasonable steps have been taken to ensure that they are correct and complete. Verification of records is undertaken by expert volunteers at the local (county) level and subsequent checks are also made on the national BNM dataset. Records are accepted from untrained amateurs, as well as skilled volunteers and professionals, but butterflies are an easy group of organisms to identify (compared to almost any other taxa). This fact, together with the verification provided by local experts (as described above) gives good grounds for confidence in veracity of the data set. Apparent errors in the data should be reported to the administrator for further investigation. The records have not been systematically checked using NBN Record Cleaner.

Method steps

1. The primary source of data is as direct field observations made by volunteers, Butterfly Conservation members, nature conservation professionals, natural historians and members of the public. No specific methodology is required: records of any butterfly species seen anywhere in the county at any time of the year by any recorders are accepted, subject to verification. However, standard minimum recording requirements exists and recorders are encouraged to adopt them (e.g. an exact date and at least a 1km grid reference). Recorders are also encouraged to note the exact or approximate abundance of each species seen. A secondary source of data is from the literature, particularly for pre-1970 records. For example, such records were extracted from the literature (in an unsystematic way and with a strong bias towards rarer species) by BRC for the Atlas of Butterflies in Britain and Ireland (Heath et al. 1984).

This dataset represents almost complete coverage of 10km x 10km grid squares in Scotland. Over 95% of the recording visits have a spatial resolution of 100m or 1km grid squares, but this varies considerably over time, with older records tending to have coarser spatial resolution.