Morecambe Bay Fritillaries

High Brown Fritillary

The Species

The High Brown Fritillary is the UK’s most threatened butterfly. Between 1976 and 2014 this species lost 96% of its known colonies. This large orange and black butterfly moves powerfully as it flies over Bracken and low vegetation in bright sunshine. The best habitat can be found in woodland clearings and wide rides where scrub or tree cover has been recently removed, or areas of well drained Bracken and grass. The caterpillar of the species requires an abundance of violets as well as dead plant material such as leaf litter, where it will shelter and pupate. 

The UK’s fourth most threatened butterfly, the Duke of Burgundy, suffered declines of 84% between 1976 and 2014. This small springtime butterfly can be found in woodland clearings and wide rides in young plantations or sizeable glades, where caterpillars will feed on Primrose. The species will also breed in limestone grassland if there are significant areas of scrub or shelter and Cowslip to feed their caterpillars.

The Pearl-bordered Fritillary is the UK’s second most threatened butterfly, experiencing declines of 95% between 1976 and 2014. This once widespread species is distinguished from other fritillaries by the row of ‘pearls’ that edge the  underside of its hindwing. The Pearl-bordered relies on very similar habitats to the High Brown Fritillary - woodland clearings, wide rides and areas of interspersed Bracken and grass with wild violets and dead plant material.

The nationally scarce White-spotted Sable moth is found on just a handful of sites across the country, and the Morecambe Bay Limestones remain a stronghold. This year we are collaborating in a  research project to examine population levels and movement, which are critical in conserving this delightful moth. It relies on a habitat of woodland clearings, wide rides and limestone grassland. The caterpillars feed on the flowers and leaves of Goldenrod, itself a declining plant.

The work we are undertaking to support these threatened species will benefit several other Lepidoptera species including the Dingy Skipper, Northern Brown Argus, Small Pearl-bordered Fritillary and Barred Tooth-striped moth. It will also help a variety of other wildlife including Dormouse, Wood Warbler, Tree Pipit, Spotted Flycatcher and Lesser Spotted Woodpecker, and plants including Juniper and Lesser Butterfly-orchid.

The Project

The landscape around Morecambe Bay contains both limestone grassland and open spaces within woodland, providing the perfect habitat for some of our rarest species. 

Even here the situation is critical for species such as the High Brown Fritillary. We have managed to maintain populations on most sites and continue to see sites being colonised where we have created woodland clearings, allowing wildflowers to flourish, supplying adults with nectar and caterpillars with food. The problem is that these sites will become overgrown and uninhabitable without ongoing management. Small colonies will die out if they aren’t able to move on to more suitable breeding habitat. Butterfly Conservation’s five-year project focuses on 17 woodland sites, with a combined area of 420 hectares. Vegetation is being cleared from the target areas to create a chain of flower-rich, sunlit clearings. This approach allows butterflies and moths to move through the landscape, breed in new areas and expand their populations to sustainable levels.

This project is working to:

  • increase the amount of woodland in coppice management to create larger areas of suitable habitat
  • establish woodland rides to provide breeding habitat and improve connectivity between sites
  • rebuild woodland infrastructure to enable woodlands to be sustainably managed in the future.

Your support will:

  • fund the Project Officer who is coordinating the project, organising volunteer training and leading conservation work parties
  • hire expert contractors to undertake specialist conservation work on the project sites
  • buy tools and protective clothing for volunteers carrying out conservation work
  • support volunteers to ensure ongoing management of the site once the project has ended.



Please help protect one of Britain's most important landscapes.






This project would not be possible without the support of WREN, Natural England, Forestry Commission England, Arnside and Silverdale AONB, Lake District National Park Authority, National Trust, Cumbria Wildlife Trust, Lancashire Wildlife Trust, RSPB, Morecambe Bay Local Nature Partnership, Morecambe Bay Limestones and Wetlands NIA, Friends of the Lake District, Tanner Trust, William Dean Trust.