One of the UK’s most endangered butterflies has more than doubled its population in parts of a Devon forest in the last decade, Butterfly Conservation (BC) can reveal.

Recent surveys carried out by the wildlife charity have shown that the rare Pearl-bordered Fritillary is thriving at the Forestry Commission’s Haldon Forest Estate.

The butterfly, which has declined by 95% in the last 40 years, can be found in small pockets of the forest near Kennford.

Conservation work to improve the quality of the butterflies’ breeding habitat at the site has been carried out over the last 18 months, funded through a grant from Coastal Recycling.

Project leader for BC, Jenny Plackett, said: “The declines affecting this stunning butterfly are really alarming, so to see it responding so well to habitat management at Haldon is just fantastic and I can confirm the butterfly is now expanding into some newly cleared areas.

“The sunny clearings favoured by the Pearl-bordered Fritillary had become overgrown with scrub, so the grant helped us to open up these areas and create corridors for the butterflies to use as flight paths to reach other clearings within the woodland.”

Pearl-bordered FritillaryCoastal Recycling’s Harry Wild said: “We are delighted that our Fund has helped contribute to restoring this rich butterfly habitat in Haldon Forest. It’s fantastic to witness first-hand the butterflies increasing in population as a direct result of the conservation work.”

The work funded through the Coastal Recycling grant has been carried out alongside the efforts of volunteers, who have helped with scrub clearing and the planting of Common dog-violets – the foodplant for this butterfly’s caterpillar.

The Pearl-bordered Fritillary flies between mid-April and late May, although this year volunteer surveyors noted a slightly later than usual start to the flight season, following the cold spell at the end of March.

The habitat management work is also benefitting the Small Pearl-bordered Fritillary. This butterfly flies a little later in the year, so can still be enjoyed throughout much of July.

The Forestry Commission (FC) remains committed to maintaining habitat patches for these butterflies at the Haldon Forest Estate.

Ben Philipps, FC’s Area Forester, said: “We are really proud of this Pearl-bordered Fritillaryarea of Haldon Forest, which has been a stronghold for butterflies for decades. The warm, sheltered microclimate provided by the surrounding woodland appears to provide the butterflies with the ideal habitat. Over recent years we have worked more closely with Butterfly Conservation and this population growth is one sign that this partnership is working.”

Nature enthusiasts won’t be able to see the Pearl-bordered Fritillary flying in Haldon Forest until next May, but people in Devon are being asked to help their local butterflies this summer by taking part in the Big Butterfly Count. The world’s largest butterfly survey is running until Sunday 7 August  2016 and anyone can take part, anywhere.