A rare butterfly introduced to part of Exmoor two years ago has more than doubled its population at the site, Butterfly Conservation (BC) can reveal.
Around 50 Heath Fritillaries were released into woodland clearings in Hawkcombe Wood near Porlock in Somerset in 2014, thanks to work by BC, the National Trust and Exmoor National Park Authority.
The butterfly bred successfully in its first year and around 20 adults were recorded during June 2015.
This year a local volunteer has recorded some 125 Heath Fritillaries in one section of recently cleared habitat, thanks to conservation work carried out by Exmoor National Park.
Jenny Plackett, BC’s South West Regional Officer, said: “We are delighted that the butterfly is continuing to thrive in the newly managed habitat at Hawkcombe. The butterflies were collected from the nearest occupied site around 3km away, and as the Heath Fritillary is such a sedentary butterfly, it is unlikely that it would have made it here without a helping hand.
“Extending the range of the Heath Fritillary this far west from its current distribution will help to strengthen the population as a whole and hopefully enable it to colonise back into its historic breeding grounds in nearby Shillett Combe. We will be monitoring the butterfly closely.”
The Heath Fritillary is one of the UK’s rarest butterflies and is restricted to just a few sites in Kent, Essex, near the Cornwall and Devon border and on Exmoor, where it can be seen flying from late May until the end of June.
On Exmoor, the butterfly is most commonly found in sheltered heathland combes where common Cow-wheat - the caterpillar’s foodplant - is abundant.
The Heath fritillary can also found in coppiced or newly felled woodland and has historically been linked with the traditional practice of woodland coppicing, giving it the nick-name of the ‘Woodman’s Follower’.
Exmoor National Park Authority has plans for ongoing management to ensure a continued supply of habitat for the butterfly in the longer term.
Graeme McVittie of Exmoor National Park said: “Coppicing of oak was once widely practiced for the production of tan-bark and charcoal, including in Hawkcombe Wood. It’s really exciting to see how re-establishing this practice of oak coppicing, which has virtually ceased elsewhere, can have such immediate and impressive conservation benefits and also provide timber and wood fuel into local markets to help make the work financially viable too.
“We are delighted to be working with Butterfly Conservation and the National Trust on this exciting project to help conserve one of the UK’s rarest butterflies.”
Want to help butterflies on Exmoor like the Marsh Fritillary?
The All the Moor Butterflies project has been developed to protect the beautiful South West Moorlands and the butterflies and moths that depend on it. It will ensure the landscape is sympathetically and sustainably managed to protect the species that rely on it for survival.
For more information, email Butterfly Conservation's Jenny Plackett: @email