Conserving the Painswick Valleys' Rare Butterflies

This funded project in the Painswick Valley landscape has helped to improve populations of two of the UK's most threatened butterflies.

The Large Blue Maculinea arion is the UK’s rarest butterfly and globally endangered. The Cotswolds was formerly one of the largest landscapes for the Large Blue butterfly in the UK until it became extinct here in 1963. This landscape which contains five former sites has been identified as a priority restoration area.

The Duke of Burgundy Hamearis lucina is one of the UK’s most rapidly declining butterflies. The Cotswolds is one of several remaining national strongholds for the butterfly but it has suffered a severe decline of 85% in the South West and urgent action is required.

The Large Blue breeds in well drained unimproved grassland, predominately in Limestone or coastal grassland. The adult lays its eggs on Wild Thyme Thymus polytrichus flower-heads which are the larval foodplant. Breeding success is best in well-grazed grasslands with a short turf where the host ant Myrmica sabuleti is abundant.

The Duke of Burgundy occurs in sheltered positions on either scrubby chalk and limestone grassland or woodland clearings. Eggs are laid on the underside of either Cowslip Primula veris or Primrose P. vulgaris leaves among vegetation with tussocks. On downland, north or west-facing slopes are preferred.

Two experimental Large Blue re-introductions have recently been made in the Cotswolds and early signs are encouraging. One of the sites is Daneway Banks, a Gloucestershire Wildlife Trust site with public access.

The extinction of the Large Blue and the dramatic decline in the Duke of Burgundy is due to the loss of unimproved grassland through habitat destruction and abandonment as well as changes in management.

Since the Large Blue became extinct in the UK in 1979, the combination of research and conservation has resulted in the most successful insect conservation programme in the world. Since its re-introduction to sites in the UK in 1984 the number of successful colonies in the South west has increased to a total of 30 in 2008 (see below for acknowledgements)

Butterfly Conservation secured two years funding from the BIFFA Trust commencing in October 2012.

Project Aims

Conserving the Painswick Valleys’ Rare Butterflies project aims to restore and maintain limestone grassland to help re-establish sustainable populations of both Large Blue and Duke of Burgundy butterflies across 11 sites.

The Large blue requires short turf with high densities of the ant Myrmica sabuleti, which it parasitizes, and a good distribution of its caterpillar food-plants Wild thyme and Marjoram. The project addresses the major conservation challenge of managing grassland sites for two rare species with different ecological requirements.

The Duke of Burgundy thrives where Cowslips and Primroses grow in high numbers and produce large plants which do not dry out during hot weather, both butterflies need shelter from scattered scrub but are threatened when the scrub becomes dominant.

Project Methods

• Habitat condition assessments will be undertaken to target the scrub management and food plant populations boosted.

• Propagation and planting of 4000 wild thyme and 4000 primula plants.

• Practical conservation, including scrub management and ruderal control, will be undertaken by contractors and volunteer work parties.

• Possible reintroduction/s when the habitat becomes suitable.

• Monitoring of butterfly and ant populations will be carried out throughout the project by specialist contractors with the help of volunteers.

• A local partnership group of conservation organisations will be established to coordinate future management and ensure work is sustained after the funding ends.

Project Results

Downloadable project update

Project Delivery

The project is managed by Butterfly Conservation’s Species Team based at our Head Office, overseen by Dr Caroline Bulman. Conservation Officer, Rachel Jones manages the delivery of the site restoration work, which includes scrub management, ruderal weed control, food-plant propagation and planting. Local contractors and volunteers carry out this vital work.

Highly experienced Large Blue contractor David Simcox is leading the research that underpins the project, undertaking surveys of food-plants, butterflies and ants and to advise on targeted management including scrub clearance, food-plant propagation and grazing regimes. The management and grazing on the project sites is carefully targeted using the results of habitat assessments, Large Blue and Duke of Burgundy monitoring and Ant surveys. Each site manager and or owner receives detailed advice on where to target the scrub management with a tailored grazing regime according to the live- stock used by their grazier.

Project Partners

The project was developed by Butterfly Conservation and works closely with Cranham Common Conservation Trust, the Gloucestershire Wildlife Trust, the National Trust, Natural England’s local NNR Team, and private landowners.  

Project Funders