High Brown Fritilary Project
The high brown fritillary (Argynnis adippe) is a large
butterfly seen flying powerfully over the tops of bracken covered
slopes and low vegetation in woodland
clearings. In flight the males are very similar to dark green
fritillary, which are often found in the same habitat. When feeding
from flowers the species can be told apart by distinctive underwing
markings.
The high brown fritillary has seen a large decline in range (up
to 94%) and in 1995 only 51 colonies existed in the whole of the
UK. Due to this significant decline it is now classified as
vulnerable in the UK Red Data Book.
It breeds in two main habitat types: bracken stands where larval
foodplants (violets) grow and woodland clearings on limestone
outcrop. The latter is believed to be restricted to the Lake
District, and all known Welsh sites are bracken covered slopes
with:
- Dense bracken stands (up to 40 to 110 cms in height) where the
ground is littered with dead bracken along with sparse grass
cover
- The larval foodplant, common dog violet Viola riviniana,
amongst sparse ground vegetation (including woodland species like
Ground Ivy Glechoma hederacea, Tormentil Potentilla erecta and Wood
Anemone Anemone nemorosa)
- A sheltered, usually south-facing, open and sunny site below
300m altitude
- A minimum area of 2 to 5 hectares of suitable habitat to
support a breeding colony
The Alun Valley Project - conserving the
last population of High Brown Fritilary in Wales