The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
Nationally rare and reduced to approximately fifty sites with Dartmoor and Morecambe Bay the strongholds. The ten year population trend in England and Wales to 2004 shows an 85% decline, the greatest of any British butterfly (Fox et al ., 2006). Although widespread and locally abundant in Europe through temperate Asia to Japan, it has declined in at least eight countries (Asher et al ., 2001).
Once found in woodland and coastal grasslands in Cornwall. Possibly extinct, but still occasionally recorded near Marsland, with one reported in 2008. There was a brief attempt at re-introduction to Cabilla Woods in July 2001, when captive bred butterflies were released into newly cleared coppiced woodland, but the introduction was unsuccessful. The populations near St. Austell and Seaton may not have survived changes to the habitat. The record at Kynance Cove in 1957 was confirmed after 39 years by the capture in 1996 of another specimen nearby. A mention of High Browns at Kynance was made by a newspaper columnist but he is reluctant to give details. Records for near Penzance in 1973 (Simpson, 1974) have not been confirmed since.
Habitat & Ecology
The female lays near the foodplant of Violets Viola spp. in suitable areas either in open woodland or on Bracken-covered grassland. The larvae require exceptionally warm vegetation and in most habitats bask on dead Bracken Pteridium aquilinum , which reaches high temperatures in spring sunshine (Warren, 1995).
Cessation of woodland management (allowing woodlands to become too dark) and cessation of grazing on Bracken-dominated grasslands.
Woodland coppicing and the maintenance of fairly high bracken densities with abundant Violet. The latter habitats are best maintained by cattle and pony grazing which breaks up the litter enough to give good densities of foodplant (Warren & Oates, 1995). A UK BAP priority species.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.