The White-letter Hairstreak isn't a butterfly most people in the Quantocks will have knowingly seen. It hadn't been recorded there since 2008, and in the 75 years before that there were only five sightings. Its disappearance tracks almost exactly with the decline of the tree it depends on: elm, decimated nationally by Dutch Elm Disease. A project led by Friends of the Quantocks, backed by £24,905.86 of Farming in Protected Landscapes (FIPL) funding across two phases, set out to bring both the tree and the butterfly back - and a third phase is now under way.
A line of dead and dying elm trees, the project is introducing Dutch Elm Disease resistant trees
A tree in trouble, a butterfly on the brink
Elm was once one of Britain's largest and longest-lived trees, rivalling oak in size and supporting a rich web of dependent wildlife. Dutch Elm Disease changed that, and took much of the White-letter Hairstreak's habitat with it - the species has declined by 80% across the UK over the past 50 years. Working with landowners across the Quantocks, the project is planting disease-resistant elm within hedgerows and parkland, and blackthorn near ash trees to support a second rare species, the Brown Hairstreak. A team of volunteers has been trained to identify elm trees and to spot the eggs, caterpillars and adults of both butterflies, including using UV lamps to find White-letter Hairstreak caterpillars, which fluoresce under ultraviolet light.
A white hairstreak caterpillar fluoresces under ultraviolet light
Training, surveying and re-discovery
Volunteers now survey through the year: eggs from November to March, White-letter Hairstreak caterpillars from mid-March to early May, adult White-letter Hairstreaks from mid-June to August, and Brown Hairstreaks from late July into September. A data schema built specifically for the project keeps every sighting and every planted tree recorded consistently, building a baseline to measure progress against.
That effort is already paying off. After an 18-year gap in sightings, the project has re-discovered three colonies of White-letter Hairstreak, with 39 individuals recorded over two years. Alongside the survey work, 438 elm trees and 60 blackthorn whips have been planted across 38 landholdings, with more than 50 landowners engaging directly with the project. The rediscovery has prompted a search for other species thought to be locally extinct, including a possible sighting of Dingy Skipper - unseen in the area for 30 years - which is now being followed up.
Volunteers are keeping an eye out for brown hairstreaks during the summer
Playing the long game
Elm trees take a minimum of 12 years to reach the maturity needed to support White-letter Hairstreak, and disease-resistant elms can live for centuries, so this is a project measured in decades rather than seasons. Its early impact was recognised with a CPRE Green Spaces Award in June 2026, with judges praising the scientific rigour behind the survey work and the way the project has engaged landowners, community groups and schools.
Elm trees give shade, sequester carbon and provide essential foodstuff for rare buterflies.
What's next
With phase three now under way, plans are well advanced for further planting this winter, with more than 20 additional landowners keen to take part. FiPL funding is expected to remain available for suitable land, with Friends of the Quantocks continuing to act as applicant so individual landowners don't carry that burden themselves. The longer-term ambition is to build relationships in every village around the Quantocks, planting elm at scale so that the tree – and the White-letter Hairstreak – become a permanent feature of the landscape once again. The project is also exploring Heritage funding for a full-time conservation officer to help take the work further.
The elm and butterfly restoration project is led by Friends of the Quantocks, supported by Quantock Hills National Landscape, and funded through Farming in Protected Landscapes (FIPL).
