These fragile yet beautifully colourful creatures help pollinate flowers and provide food for birds. Ennerdale provides a home for a number of species of butterfly including Red Admiral, Marsh Fritillary, Small Copper, Orange Tip, Peacock, Small Tortoiseshell, Painted Lady, Ringlet, Meadow Brown, Green Veined White.
Where to See
Butterfly’s can be seen across the western end of the valley, around the lake, in the fields in the middle of the valley and along the forest roads.
Butterflies are most active on warm calm days and can be seen between May and September with July and August being the best months.
Led by Butterfly Conservation and Natural England the Wild Ennerdale partners have been working to restore a thriving Marsh fritillary population to the Ennerdale Valley. Changing from intensive sheep grazing to extensive cattle in 2009 has seen a great increase in devils bit scabious (the food plant for marsh fritillary larvae) across the valley floor as the cattle are more selective than sheep in their grazing. In April 2011 3800 marsh fritillary larvae were released into the fields in the middle of the valley just before Easter.
In addition to our work with Marsh fritillary we are seeing more diverse habitats developing through our introduction of extensive grazing cattle and removal of fence boundaries and allowing the River Liza freedom to create new gravel bars. These are helping expand habitats suitable for butterflies.
Wow! Marsh Fritillary
From 2014 and 15 survey results Butterfly Conservation and Natural England tell us that our marsh fritillary population at the Mill has the highest density of anywhere in England. They also say the Gillerthwaite fields population is heading towards being the largest in England.
The Marsh Fritillary Story
The Marsh fritillary butterfly has experienced a 55% decline in the number of colonies in the UK since 1970 and a decline of up to 50% across Europe since 1980. It is one of the most highly protected butterflies in Europe.
To survive it requires a number of linked, lightly grazed wet grassland sites that are untreated by chemical fertilisers and herbicides, this habitat has declined by 97% since 1940 and access to its only preferred larval food plant, devils bit scabious..
The butterfly was historically relatively common across north and West Cumbria but the numbers dwindled as a consequence of increased sheep grazing and wetland drainage. The last surviving handful of Cumbrian Marsh fritillary caterpillars, then only present at one site, were taken into captivity under licence by Natural England in 2004. They were cross bred with stock from closely related Scottish colonies and were released back into 4 sites in spring 2007.
The Marsh fritillary in Ennerdale.
Historically the Marsh fritillary was present across Ennerdale bu the last population on Longmoor common became extinct in 1979.
Between 2007 and 2011 five sites across the valley have seen reintroductions of the species so that now there is a what we call a metapopulation of five colonies with connectivity corridors between them and other smaller ‘satellite’ pockets of suitable habitat nearby. Typically reintroduction invloves site survey, change of management from intensive sheep to extensive cattle followed by the introduction of 4000 to 8000 larvae in April and May. The five colonies include Longmoor, Hunter How, The Old Mill and Mireside at the west end of the valley and Gillerthwaite Fields in the middle valley.
Annual population monitoring is carried out by Butterfly Conservation with support from Wild Ennerdale volunteers. This entails counts of flying adult butterflies in mid to late May and counts of larval webs in late August.
Read more about this great story in Butterfly Conservation's Spring 2015 Newsletter