Hampshire and Isle of Wight Butterfly and Moth Society
Hampshire and Isle of Wight Butterfly and Moth Society
| Family: | Nymphalidae |
| Subfamily: | Heliconiinae |
| Genus: | Boloria |
| Species: | euphrosyne |
| Authority: | (Linnaeus, 1758) |
This woodland butterfly gets its name from the series of "pearls" that run along the outside edge of the underside of the hindwing. Males are often seen flying swiftly, low across the breeding site in search of a mate and are extremely difficult to follow, the colouring of the wings providing excellent camouflage against the dead bracken that is often found at these sites. The Pearl-bordered Fritillary may fly with the Small Pearl-bordered Fritillary at certain sites, although the Pearl-bordered Fritillary, which emerges a couple of weeks before the Small Pearl-bordered Fritillary, generally appears much paler in colour as a result.
In England and Wales this butterfly in scattered and isolated colonies south-west of a line running between Denbighshire in the north-west to East Kent in the in south-east. There are also colonies in Westmorland and West Lancashire. It is also widespread in central Scotland, but very local or absent in the north and south of the country. In Ireland it is found in the Burren limestones of Clare and South-east Galway. It is absent from the western and northern Isles of Scotland, the Isle of Man and the Channel Islands. This butterfly forms discrete colonies which vary wildly in numbers, from a couple of dozen to over a thousand, this being largely-determined by the availability of suitable habitat. Most colonies contain a few dozen adults.
| #Individuals | #Tetrads | 2022 | 2023 | Abundance Trend | 2022 | 2023 | Distribution Trend |
|---|---|---|---|---|---|
| 1312 | 912 | -30% | 9 | 10 | +11% |
| #Records | #Individuals | Earliest Record | Latest Record | |
|---|---|---|---|---|
| All Records | 3,941 | 24,985 | 17/04/2003 | 09/07/1950 |
| 2023 | 212 | 912 | 10/5/2023 | 14/6/2023 |
| Location | Date | Quantity | |
|---|---|---|---|
| Earliest Record | New Forest | 10/5/2023 | 2 |
| Latest Record | Frohawk transect: Section 3 | 14/6/2023 | 2 |
| Highest Count | New Copse Inclosure | 17/5/2023 | 60 |
One of the issues with 'raw' trend data is that there is inherent bias based on the number of recorders. For example, the number of individuals and populated tetrads recorded are likely to increase if there is an increase in the number of recorders. In order to remove this bias, the normalised trends use data that has been recalculated using the average number of recorders over the trend period. This normalisation gives a much better picture of the true trends.
Average #Recorders: 32.2
Average #Recorders: 32.2