The pearl-bordered fritillary is a Priority Species in Britain. Changes in woodland management in recent years have led to the decline of this once common species. It is now most common in Scotland and southern England.
Pearl-bordered fritillary (Boloria euphrosyne)
Pearl-bordered fritillaries live in woodland clearings where trees have recently been cut down or coppiced, and where there are areas of grass, bracken and open scrub. They live in small populations, but these populations are linked and butterflies often fly between different colonies that are sharing a suitable habitat. The pearl-bordered fritillary depends on a mosaic of open areas for movement between colonies and for food.
Individual eggs are laid in the autumn on bracken or and other nearby vegitation.
The eggs develop during late spring and the caterpillars grow from June to the following April, hibernating over the winter. The adult butterfly emerges between the 3rd week in April and the 3rd week in May.
Both caterpillars feed on common dog-violet and sometimes heath dog violet and marsh violet and adult butterflies feed on the necter of Bugle.
Changes in woodland management over recent years have led to the decline of the species. Woodland practices such as coppicing and thinning are in decline, and many areas have been planted with conifers. Woodland rides and clearings have become increasingly shady and overgrown. Bracken habitats are no longer managed through grazing.
The pearl-bordered fritillary is most easily confused with the small pearl-bordered fritillary. It can be distinguished by two silver 'pearls' on the underside of the hind wing.
How we manage our woods
The Forestry Commission is working closely with Butterfly Conservation to make sure that open habitats in woods and forest are appropriate maintained. Suitable habitats are being created by coppicing and opening up woodland rides.