UK Butterfly Monitoring Scheme (UKBMS)

Quality Control

Confidence in the data is good. Automatic rules are used to classify some records as 'assumed correct'; other records are reviewed by expert verifiers.

Method steps

1. The methodology and development of transect monitoring for butterflies has been reviewed in detail elsewhere (Pollard and Yates, 1993). In brief, a fixed-route walk (transect) is established at a site and butterflies are recorded along the route on a regular (weekly) basis under reasonable weather conditions for a number of years. Transect routes are chosen to sample evenly the habitat types and management activity on sites. Care is taken in choosing a transect route as it must then remain fixed to enable butterfly sightings to be compared from year to year. Transects are typically about 2-4km long, taking between 45 minutes and two hours to walk, and are divided into sections corresponding to different habitat or management units. Butterflies are recorded in a fixed width band (typically 5m wide) along the transect each week from the beginning of April until the end of September yielding, ideally, 26 counts per year.

UK.