THE MARSH FRITILLARY
IN CUMBRIA

  • This stunningly beautiful butterfly was just managing to hang on at one or two colonies in the Lakeland area but by 2005 none were reported, suggesting it had become extinct.
  • After the Second World War there were over 200 colonies in north Cumbria from Ennerdale to Penrith. Colonies from the Solway Mosses, Ennerdale and Eskdale have long since gone. The butterfly was once abundant just 3 km west of Carlisle in the meadows around Orton Woods and a few km further west at Finglandrigg Wood.
  • The remaining colonies were so isolated that efforts to improve the habitat had no beneficial effect because there was no mixing between colonies and in-breeding led to low productivity and weak specimens.
  • Fortunately in 2004 it was realised that the last remaining colony was under threat and 168 larvae were removed under licence for captive breeding. A further 800 larvae were added to these under licence from a strong colony in Argyll, Scotland, that was genetically similar.
  • After successive years of breeding, by early 2007 around 40,000 larvae were held in captivity. In March of that year some 37,000 were released back to four prepared sites, again under licence. The largest number were released at a central Lakes site, with others on the Solway, in West Cumbria and near Penrith. Hopefully this will lead to a resurgence of the species in the county.
  • Three of the four sites are on private land and their locations will not be divulged. The fourth site is Finglandrigg NNR between Kirkbampton and Kirkbride on the Solway Plain. This wardened site is being used to provide an opportunity for members of the public to see this terrific species. At the car park (map ref NY 283572) follow the butterfly trail about a mile through the wood until you come to an open area through a gate with a sign on it saying 'you've finally made it, this is the site'!
  • In 2007 there were very encouraging signs that the release programme was working well, except at the Penrith site where conditions are still not ideal. Good numbers of adults were seen during the flight season and larval webs found from mid-August onwards.
  • Massive declines in populations throughout Europe make this the only butterfly in the U.K. to gain protection under the E.U. Habitats and Species Directive.
  • Colonies do undergo huge fluctuations in size over the years, but it is the disappearance of colonies that is worrying.
  • The Orton Wood colony was studied for 55 years. Between 1881 and 1894 it increased from common to very abundant, before declining over the next ten years, then becoming scarce between 1906 and 1912 and very rare between 1913 and 1919. Numbers increased steadily between 1920 and 1925 and by 1935 it was described as excessively common. Sadly this colony is now extinct.
  • The Marsh Fritillary is predominantly a species of damp unimproved grassland on the western side of Britain; its food plant is Devil's-bit Scabious (although it will use Honeysuckle when pressed). The peak flight time in Cumbria is usually the first two or three weeks of June.
  • The 'improvement' of old pasture for intensive agriculture leads to the eradication of the foodplant. Colonies become fragmented and the species cannot survive population crashes by recolonisation from neighbouring colonies nor can genetic reinforcement occur by mixing of populations.
  • The larvae need direct sunlight - they like to bask in the warmth as an aid to digestion (don't we all!).
  • Bad, particularly wet, weather at critical times (and for several years in succession) affects the success of the species. Numbers are further reduced by a parasitic wasp, which injects its eggs into the larvae so that they are eaten from within!
  • Recolonisation depends on the presence of adjacent colonies; females will wander several kilometres, especially towards the end of their flight period (when the weight of eggs carried is reduced).
  • The Ministry of Defence look after possibly the largest colony in Europe - in 1999 it was estimated that 10,000 larval webs were present on the Salisbury Plain Training Area. Nice to know our taxes are being put to good use!!

 

LINKS TO PAGES

DOWNY EMERALD DRAGONFLY
HEDGEHOGS
LADY'S SLIPPER ORCHID
NATTERJACK TOAD
REED WARBLERS
SWALLOWS
TERNS
TREE PIPITS
TREE SPARROWS