‘We’ve done it at Dunnet’ – rare butterflies return to Caithness site thanks to environmental project

Caithness volunteers can give themselves a pat on the back for helping a rare butterfly come back from the brink to find a home in the county.

An idea developed from a community event about small blue butterflies has become a great success story at Dunnet Forest in 2024, building on previous conservation work by Caithness Environment Volunteers.

The rare small blue butterfly is Britain’s smallest butterfly. Declining across the UK, it is a priority species for the Species on the Edge (SotE) programme on the far north coast of Scotland. Small blue butterflies occur at 80 sites in Scotland, but only in small numbers; in Caithness they are found along the coast between Scrabster and Dunnet.

The idea was to build a butterfly bank – a sheltered, sunny bank, planted with wildflowers for butterflies.

Sarah Bird, SotE senior project officer for the north coast area said: “We planned to plant kidney vetch on our bank as it is the food plant of small blue caterpillars.

“A small team from Caithness Environment Volunteers and staff at Dunnet Community Forest led the project.

“A site in meadows at Dunnet Forest was chosen because small blues already breed in nearby dunes. Designs were discussed with colleagues at Butterfly Conservation, and NatureScot gave approval for the construction in Dunnet Links Site of Special Scientific Interest (SSSI).

“UHI Supported Learning group were keen to help too and made superb signs.”

After building and planting the bank, the team waited anxiously for small blue butterflies, which usually emerge in late May in Caithness. Excitement and anticipation filled their heads but they were unsure if it would work.

Sarah continued: “Expectations built further at Small Blue Day on May 12, when we reminded local visitors what the butterflies look like, where to see them, and how to record sightings.

“It was a beautiful sunny day, and kidney vetch flowers were just starting to open. May 13 bought the first 2024 Caithness small blue sighting at Castlehill – warm weather brought the butterflies out early. On May 19 our most enthusiastic Scottish countryside junior ranger, Daniel Parlour, spotted a small blue on a broom bush near the butterfly bank.

Then, on May 27, Sarah received an email from a woman who was on holiday and visiting Dunnet Forest which said: “At least eight small blue butterflies at Dunnet butterfly bank today. Margaret.”

“Wow, thank you, Margaret. That was my favourite email of 2024. It represented success on so many levels. Small blue butterflies found our butterfly bank.”

Margaret had followed signs made by UHI Supported Learning Group, from the car park to the bank and recognised a small blue butterfly. She then used the email on the sign to let Sarah and her team know and the celebrations began.

“The following day we saw 17 small blues, including two on the kidney vetch plants we had carefully planted. The last record at the butterfly bank was a single small blue on July 7.”

Daniel Parlour, junior ranger, took on wildlife monitoring and management at the butterfly bank over the summer. He said: “The butterfly bank that we constructed in spring, has done wonderfully.

“Throughout the summer it has been my job to monitor the bank, count the plants on it, remove weeds and keep a look out for small blue butterflies. The team were very pleased that all of the essential plants flowered, and numerous small blues were seen on the bank.

“Since summer the bank has changed a lot; it’s gone from a sea of yellow from the kidney vetch flowers to a desert of grey. But, as the kidney vetch flower heads died, wilted and dried out, they released lots of seeds onto the bank. We hope this will lead to the butterfly bank self-seeding next year, and a new generation of kidney vetch growing.

“The successes of the first bank means, to my delight, that next year we’re planning on constructing another butterfly bank.”

Sarah says that Daniel has also been a “superb ambassador” for small blue butterflies and has been educating many people about them.

“2024 has been a big success for small blues, and we hope to build on that success. Butterfly bank number two will be bigger and better, providing more shelter from the wind, and more exposed stone for butterflies to sunbathe.

“Thanks to everyone who helped; all who sent in records, grew kidney vetch, made signs, did timed counts and habitat management, and supported in other way. Special thanks to Daniel and Margaret, of course. This species on the edge is getting a real boost in Caithness.”

Sarah Bird can be contacted by email at: sarah.bird@plantlife.org.uk

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