Small Pearl-bordered Fritillary (Boloria selene)

Species description
© - Nick Greatorex-Davies

The Small Pearl-bordered Fritillary was once widespread in Britain occurring in woodland clearings, damp grassland, heaths and dunes and other damp habitats where its foodplants, mostly Dog Violet (Viola riviniana) and Marsh Violet (Viola palustris), grew. With the demise of coppicing and intensification of agriculture the species has disappeared from many of its former sites becoming scarcer throughout its range, and it is now extinct in nearly all of central and eastern England. (For further details on this species see http://www.butterfly-conservation.org/).

Status
Resident
Trend summary

Status since 1976 is Rapid decline with a change of -68.3% since monitoring began for this species.
Status over the last 20 years is Stable with a change of -18.9%
Status over the last 10 years is Rapid decline with a change of -37.2%

Log Collated

This chart shows the index of abundance (LCI = Log Collated Index) over time. It shows fluctuations in populations from year to year, and is scaled so that the average index over the whole series is equal to 2 (horizontal line). Further details on the analysis of UKBMS data can be found [here]

This chart shows the average number of butterflies seen on transects between Arpil and October across all sites (fitted values from a Generalised Additive Model). The blue line gives average counts over the full BMS series (1976 to date) and the red line gives the average for the last year.

This map shows symbols for the mean abundance at transect sites, with the colour of the symbol reflecting the level of abundance. Means are over all years. Grey background squares are the occupied cells as shown by the Butterflies for the New Millenium over the previous ten year period.