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Special Areas of Conservation

1065 Marsh fritillary butterfly Euphydryas (Eurodryas, Hypodryas) aurinia

Invertebrate species: arthropods

Description and ecological characteristics

The marsh fritillary butterfly Euphydryas aurinia is found in a range of habitats in which its larval food plant, devil’s-bit scabious Succisa pratensis, occurs. Marsh fritillaries are essentially grassland butterflies in the UK, and although populations may occur occasionally on wet heath, bog margins and woodland clearings, most colonies are found in damp acidic or dry calcareous grasslands (including 6410 Molinia meadows on calcareous, peaty or clayey-silt-laden soils (Molinion caeruleae) and 6210 Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia)). In Northern Ireland it occurs in fens and on sand dunes. Management in both wet and dry situations is predominantly by low-intensity cattle or pony grazing. Sheep selectively graze devil’s-bit scabious and are therefore detrimental to marsh fritillary populations, except at very low stocking rates. Burning and mowing are also known to have caused the extinction of populations.

Populations of marsh fritillary vary greatly in size from year to year, and, at least in part, this is related to cycles of attack from parasitic wasps. Adults tend to be sedentary and remain in a series of linked metapopulations, forming numerous temporary sub-populations, which frequently die out and recolonise. Where unable to do this, populations do not seem to be able to persist in habitat fragments. It is therefore essential to conserve a cluster of sites in close proximity.

The sedentary behaviour of the adults and increasing fragmentation of their preferred habitats has led to the establishment of local races. The marsh fritillary is an extremely variable butterfly, with 34 subspecies described from Europe alone. Populations of this species found in Argyll and the Inner Hebrides are regarded as a distinct form Euphydryas aurinia scotica.

Distribution of SACs/SCIs/cSACs with species 1065 Euphydryas (Eurodryas, Hypodryas) aurinia. Click image for enlarged map.

European status and distribution

Euphydryas aurinia has declined dramatically in Europe and is regarded as endangered or vulnerable in most of its European range. On the basis of existing knowledge, the UK and Spain constitute the European strongholds for this species.

UK status and distribution

Although formerly widespread in central and eastern England, Euphydryas aurinia is now mainly confined to western and northern parts of the UK. It has become extinct over a large part of its former range, having declined by about 60% since records began. The species continues to be vulnerable in many parts of its range. Important centres of distribution are in south-west England (particularly Devon, Dorset and Wiltshire), south and west Wales, and western Scotland.

View UK distribution of this species.

Site selection rationale

Site selection has been influenced by the importance of UK marsh fritillary populations in a European context. Sites have been selected to take account of the diversity of ecological situations in which the species occurs, including wet and dry grassland, heathland, fens and sand dunes. The selected sites represent the broad geographical distribution of marsh fritillary in the UK, and include Scottish sites which hold distinctive forms of the species. The dependency of closely-related metapopulations has been taken into account, and so the SAC series includes the larger and more complex sites where the species occurs. While the SAC series makes a contribution to securing favourable conservation status for this Annex II species, wider measures are also necessary to support its conservation in the UK, including implementation of the Species Action Plan.

Site accounts

  • Aberbargoed Grasslands East Wales
    A large and relatively isolated population of marsh fritillary Euphydryas aurinia is present on a series of damp pastures and heaths in Gwent, representing the species on the eastern edge of its range in Wales.
  • Aughnadarragh Lough Northern Ireland
    Aughnadarragh Lough contains a variety of wetland habitats, including lake, fen, cutover bog and wet grassland. The area is particularly notable as one of the longest-established colonies of the marsh fritillary butterfly Euphydryas aurinia in Northern Ireland. The species was first recorded in 1984, with records in most years since then, and annually since 1990.
  • Ballykilbeg Northern Ireland
    Ballykilbeg is a relatively large wetland site with a variety of habitats including fen and wet grassland. The area is particularly notable for the large colony of marsh fritillary butterfly Euphydryas aurinia (168 larval webs were recorded in 1999). First recorded in 1996, there have been records of adults and larvae each year since.
  • Blaen Cynon East Wales
    Blaen Cynon contains an extensive complex of damp pastures and heaths supporting the largest metapopulation of marsh fritillary Euphydryas aurinia on the southern edge of the Brecon Beacons National Park.
  • Breney Common and Goss and Tregoss Moors Cornwall and Isles of Scilly
    This is a cluster of three marsh fritillary Euphydryas aurinia sub-populations over a complex of wet heathland sites. This supports the largest metapopulation in Cornwall and probably the most westerly viable population in England.
  • Caeau Mynydd Mawr West Wales and The Valleys
    Marsh fritillaries Euphydryas aurinia occur over a wide area of traditionally-managed purple moor-grass Molinia caerulea pastures in south-east Carmarthenshire. The extent of suitable habitat, contained within more than 30 enclosures at Caeau Mynydd Mawr, suggests that this is one of the largest metapopulations in Wales.
  • Cerne and Sydling Downs Dorset and Somerset
    This site supports a large marsh fritillary Euphydryas aurinia metapopulation composed of two large and one smaller sub-populations which regularly expand into other nearby areas in favourable years. These colonies occupy calcareous downland situations and complement the wet grassland habitats of the other Dorset strongholds.
  • Corsydd Eifionydd West Wales and The Valleys
    Corsydd Eifionydd contains a series of unimproved damp pastures on the eastern edge of the Lleyn Peninsula and supports the most significant metapopulation of marsh fritillary Euphydryas aurinia in north Wales.
  • Culm Grasslands Devon
    Culm Grasslands in south-west England contains the largest cluster of sites for marsh fritillary Euphydryas aurinia in the south-west peninsula. It is judged to be the most important location for the species in its major south-west stronghold.
  • Cumbrian Marsh Fritillary Site Cumbria
    This is a complex of three marsh fritillary Euphydryas aurinia populations which may form a single metapopulation. They inhabit a damp purple moor-grass Molinia caerulea grassland/scrub mosaic. This and the Bassenthwaite Moss population at River Derwent and Bassenthwaite Lake cSAC comprise a north-western set of populations which are genetically different to the other English populations.
  • Gower Commons/ Tiroedd Comin Gŵyr East Wales
    This is a cluster of at least five large sub-populations in a small area within the south-west Wales stronghold of marsh fritillary Euphydryas aurinia. This cluster of sites represents the species in south Wales, and recent survey work has shown that this population constitutes the second most important area for the species in Wales.
  • Gweunydd Blaencleddau West Wales and The Valleys
    This mixture of wet heath and damp grassland at the head of the Eastern Cleddau contains the most extensive habitat network for marsh fritillary Euphydryas aurinia in Pembrokeshire and, in conjunction with the nearby population at Waun Isaf (Preseli cSAC), supports the strongest metapopulation of the species in this area.
  • Montiaghs Moss Northern Ireland
    Montiaghs Moss is an extensive area of cut-over bog, which contains one of the largest and longest-established populations of marsh fritillary Euphydryas aurinia in Northern Ireland. The population is very dispersed throughout the entire site, reflecting the extent of habitat that is suitable for the species.
  • Murlough Extra-Regio, Northern Ireland
    Murlough is an extensive coastal sand dune system, with a wide variety of habitats. The site holds one of the largest populations of marsh fritillary Euphydryas aurinia in Northern Ireland, with a number of sub-populations present. The population is long-established and well-studied.
  • Preseli West Wales and The Valleys
    The 33 ha common of Waun Isaf within Preseli cSAC supports one of the largest populations of marsh fritillary Euphydryas aurinia in west Wales. The populations at Waun Isaf and the adjacent Gweunydd Blaencleddau cSAC together form the most important marsh fritillary metapopulation in Pembrokeshire.
  • Quants Dorset and Somerset
    This damp and sheltered site supports a medium-sized but strong marsh fritillary Euphydryas aurinia population in a neutral grassland/fen mosaic. It is strategically placed close to other smaller sub-populations, with which it forms a metapopulation, and may exchange individuals with the large population at Southey Moor (outside the SAC series).
  • Rhos Llawr-cwrt West Wales and The Valleys
    This exceptionally large population (possibly the largest in the UK) represents marsh fritillary Euphydryas aurinia in its mid-Wales stronghold. This is a site at which both core and satellite populations exist. This site was selected because of the population size and because it is judged to be viable on its own merits (i.e. not relying on other sites in the vicinity).
  • Rhos Talglas West Wales and The Valleys
    Rhos Talglas contains 53 ha of unimproved purple moor-grass Molinia caerulea pasture and supports one of the largest marsh fritillary Euphydryas aurinia populations in west Wales.
  • Rinns of Islay Highlands and Islands
    The Rinns of Islay supports a large, extensive metapopulation of marsh fritillary Euphydryas aurinia, the largest known in Scotland and one of the largest in the UK. It is well-known as a high-quality area for the species, with records dating back over a number of years. Records for the species are patchy across the overall Rinns area and so the proposed site is made up of a complex of areas which are known to hold some core parts of the overall Rinns metapopulation (together with the neighbouring Glac na Criche cSAC) which persist even when the marsh fritillary is at a low stage in its population cycle. The population is of the Scottish form E. aurinia scotica, which is completely isolated from populations in England and Wales.
  • River Derwent and Bassenthwaite Lake Cumbria
    This site supports the largest area of appropriate habitat, M25 Molinia caerulea – Potentilla erecta mire, in Cumbria. The marsh fritillary Euphydryas aurinia population is spread over four habitat patches where numbers fluctuate annually but collectively form a moderate-sized and stable population.
  • Rooksmoor Dorset and Somerset
    Representing marsh fritillary Euphydryas aurinia in the southern part of its range in England, Rooksmoor is an exceptionally large population within a cluster of sites in the Dorset stronghold. A large outlying population at Lydlinch has been included in this site as it is considered to be part of the metapopulation in this area.
  • Salisbury Plain Gloucestershire, Wiltshire and Bristol/Bath area, Hampshire and Isle of Wight
    Salisbury Plain represents marsh fritillary Euphydryas aurinia in chalk grassland in central southern England, and contains a cluster of large sub-populations where the species breeds on dry calcareous grassland. The site extends the range of ecological variability included in the SAC series.
  • Taynish and Knapdale Woods Highlands and Islands
    A large population at Taynish and Knapdale in western Scotland represents marsh fritillary Euphydryas aurinia in the northern part of its UK range. The population is most likely part of the same metapopulation present at Tayvallich Juniper and Coast, and is of the Scottish form E. aurinia scotica, which is completely isolated from populations in England and Wales.
  • Tayvallich Juniper and Coast Highlands and Islands
    This site contains a number of marsh fritillary Euphydryas aurinia sub-populations which are most likely part of the same metapopulation present at Taynish and Knapdale Woods. Together with the latter site, Tayvallich Juniper and Coast represents the species in the northern part of its UK range. The population is of the Scottish form E. aurinia scotica, which is completely isolated from populations in England and Wales
  • West Dorset Alder Woods Dorset and Somerset
    This is a large area of grassland/scrub mosaic with an extensive flushed grassland and fen component. The marsh fritillary Euphydryas aurinia population is small but stable and has the potential to expand over a wide area of favourable habitat.
  • Yerbeston Tops West Wales and The Valleys
    This isolated metapopulation in southern Pembrokeshire supports over 1500 adult marsh fritillaries Euphydryas aurinia and is an important outlier for the conservation of the species in west Wales.

SACs where this Annex II species is a qualifying feature, but not a primary reason for site selection

Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.

Please note that the map shows sites where the presence of a feature is classed as ‘grade d’, but these sites are not listed. This is because ‘grade d’ indicates a non-significant presence.