Forest butterfly survey provides hidden surprise

PBF web II

Proposals to reintroduce a population of rare and endangered butterflies to the Trossachs have been shelved - after preparatory survey work this year found a ‘secret’ population!

The Pearl-bordered Fritillary butterfly, which is now very rare in England and Wales, but more widely found in the north of Scotland, was thought to be locally extinct in the Trossachs.

With only one butterfly having been seen in the area over ten years ago, Forest Enterprise Scotland (FES) was working with Butterfly Conservation Scotland, RSPB, Woodland Trust Scotland & CLEAR Services to explore the possibility of a reintroduction programme.

Paul Maplebeck of Butterfly Conservation Scotland said;

“As part of the preparation for a possible Pearl-bordered Fritillary reintroduction, a team of volunteers was recruited to carry out a large-scale survey to visit the sites that were most suitable for the butterflies. Ideal habitat consists of sunny, south facing slopes with well drained soils and light woodland cover.

“Cutting edge scientific modelling was used to predict where these might be found - and it worked!

 “You can imagine our surprise and delight when the surveys revealed that FES sites within the Great Trossachs Forest NNR housed a secret population.  At least 45 butterflies were recorded at ten different locations in May this year.”

All of the sites where the butterflies were found were on south facing hillsides at the eastern end of Loch Katrine and featured open glades within mature woodland, with light bracken cover and clusters of favoured nectar plants such as bugle, primrose, and an abundance of common dog violet – the caterpillar’s food plant.

The survey also discovered areas of favourable habitat across FES managed ground and at sites on the Glen Finglas estate owned by Woodland Trust Scotland.

The Great Trossachs Forest, which is Scotland’s second largest designated National Nature Reserve covering over 16,000 hectares, is the long-term legacy of a forest restoration project involving Forest Enterprise Scotland, RSPB Scotland and Woodland Trust Scotland.

Katy Anderson, FES Habitats Manager added;

“This is a fantastic example of partnership work and how the combined experience, skills and resources - and the invaluable help of volunteers – can make a real difference.”

Nick Cooke of the CLEAR Services consultancy said:

“After 10 years of fruitless searching around Loch Katrine, this is excellent proof of the value of data modelling. We hope that this project will give the Pearl-bordered Fritillary population in the Trossachs a much brighter future.”

Further survey work over the next two years will help inform ongoing conservation management to help protect the species and ensure its long- term survival in the area.

Notes to editors

  1. Forestry Commission Scotland is part of the Scottish Government's Environment and Forestry Directorate.
  2. Tha Coimisean na Coilltearachd Alba na phàirt de Bhuidheann-Stiùiridh na h-Àrainneachd is Coilltearachd aig Riaghaltas na h-Alba agus bidh e a’ toirt seachad comhairle air poileasaidhean coilltearachd agus air riaghladh. Tha Iomairt Choilltean na h-Alba na fo-bhuidheann aig Coimisean na Coilltearachd a tha a’ ruith Oighreachd na Coille Nàiseanta as leth Ministearan na h-Alba.
  3. The Pearl-bordered Fritillary features on the Scottish Biodiversity List and is a priority species under the Loch Lomond & Trossachs National Park’s Biodiversity Action Plan for 2013-20. Predictive modeling was used to map the potential distribution based on a range of set criteria.  Priority survey areas were identified by applying scores to determine the optimum 1Km Ordnance Survey squares in which to search.
  4. Butterfly Conservation is the largest charity of its type in the world. Our aim is the conservation of butterflies, moths and their habitats. We run conservation programmes for more than 100 threatened species and manage over 30 nature reserves. www.butterfly-conservation.org @savebutterflies . BC has more than 2000 members living in Scotland www.butterfly-conservation.org/scotland where we work closely with local communities, landowners, the Scottish Government, Scottish Natural Heritage and other conservation partners, to safeguard Scotland’s butterflies, moths and their habitats.
  5. Media enquiries to Paul Munro, Forestry Commission Scotland press office, 0300 067 6507 / 07785 527590 / This email address is being protected from spambots. You need JavaScript enabled to view it.