Please donate to help prevent the local extinction of one of the UK’s most threatened and iconic species – the marsh fritillary butterfly (Euphydryas aurinia). The butterfly has undergone catastrophic declines throughout much Europe and the UK in recent decades. Although Wales remains a relative stronghold, even here many localised extinctions have taken place.

“If we are to truly reverse the decline of nature in Wales it is clear that we need additional approaches to nature conservation. It’s great to see such positive action for the iconic marsh fritillary butterfly and to think that although this might be the first project of its kind in Wales, it won’t be the last”

Iolo Williams: TV Broadcaster and Naturalist

INCC are licensed to take up to 80 marsh fritillary caterpillars from the wild to start a captive breeding and rearing programme. In spring 2021, INCC, along with project partners will be collecting marsh fritillary caterpillars with the aim of restoring a dwindling population in the Upper Ely landscape of South Wales.

Once collected, the caterpillars will be moved to a rearing pen situated at the National Botanic Garden of Wales and allowed to pupate. A small number of pupae will be carefully moved to their new habitat at Llantrisant Common. The emerging adult butterflies will then hopefully establish a breeding population at the Common for the first time in thirty years. Over the next four years, the project aims to release thousands of marsh fritillaries into the landscape to help boost the population.

Why the Marsh Fritillary Butterfly
Conservation for marsh fritillaries in Wales has for many years focused on monitoring populations and trying to influence policy to better manage existing habitats. Despite the tireless work of volunteers, conservation organisations and many landowners, the marsh fritillary continues to decline. It is becoming increasingly apparent that greater conservation effort is needed if we are to protect the species from further localised extinctions in Wales.

Marsh Fritillary Caterpillars in Larval Web

Due to national and international declines, marsh fritillaries are included on Annex II of EEC/EU Habitat and Species Directive. A total of ten Special Areas of Conservation (SACs) have been designated in Wales, where the marsh fritillary is a primary reason for site selection. The species is also listed as ‘a living organism of principal importance for the purpose of maintaining and enhancing biodiversity in relation to Wales’ (Environment (Wales) Act 2016).

The decline of the species is associated with the loss of its marshy grassland and rhôs pasture habitat. When managed appropriately these habitats provide the ideal sward structure required by the caterpillars and their food plant. The loss of grassland habitats, predominantly through agricultural intensification, has resulted in fragmented landscapes which support fewer and fewer areas suitable for the species.

Cattle grazing is the best way to manage marsh fritillary habitat.

Project Location
The population restoration project will take place in South Wales, within the Upper Ely landscape encompassing the towns of Llantrisant and Tonyrefail. Despite its UK significance the Upper Ely marsh fritillary population is declining and has been in steady, continuous decline for at least 25 years.

A key area for the butterfly is Llantrisant Common, situated to the south of the landscape and covering an area of over 113 ha of contiguous rhôs pasture habitat. A combination of historic and current extensive cattle grazing has created the ideal habitat for marsh fritillaries with an abundance of devil’s-bit scabious and other wetland vegetation.