A record-breaking number of small blue butterflies has been recorded in the Scottish Highlands, offering a glimmer of hope for one of the nation’s most threatened butterfly species.
In one 90-minute count, a volunteer for the charity Butterfly Conservation logged an astonishing 523 small blue butterflies at Balnagown Estate near the port town of Invergordon – more than double last year’s number.
This dramatic rise follows a warm spring and years of dedicated habitat restoration, and coincides with Small Blue Week (31 May–7 June), which celebrates and raises awareness of this tiny but important insect.
Explosion of small blues
The small blue (Cupido minimus) is the UK’s smallest resident butterfly, with a wingspan of just 2–3cm. It has suffered severe declines in recent years due to habitat loss and changing land use. Since 2005, its abundance (number of individuals counted at sites) has fallen by 39% in Scotland alone.
But this year, something extraordinary is happening.
“It has genuinely been astonishing to see these numbers of small blue on the wing,” says Tracy Munro, Species on the Edge project officer at Butterfly Conservation.
"To record over 500 at a single site is staggering and really highlights the benefits of our work with landowners and volunteers to create habitat for this charismatic wee butterfly.”
Balnagown has been at the heart of Butterfly Conservation’s efforts since 2020, when the charity began working with estate managers and local volunteers to manage and expand suitable habitat.
Richard Aspinall, the volunteer who counted the butterflies, says that "it is a rare experience now, but a real pleasure, to see such abundance coming from dedicated conservation and land management efforts.”
Populations of small blues are rising elsewhere, too. At Nairn Beach, a seaside town on Scotland's north-east coast, volunteers found 31 butterflies – more than double last year’s 13. At nearby Lossiemouth, 72 were counted compared to 16 the year before.
The butterfly has even been spotted as far north as Wick and as early as April; a rare occurrence in Scotland.
Butterfly Conservation believes the population spike could lead to a second brood later this summer, which is almost unheard of in Scotland. This could further boost numbers and help the species spread.
The charity is calling on the public to report sightings using the iRecord Butterflies app to help track this year’s boom.
Butterfly-friendly planting efforts, such as kidney vetch cultivation (small blue caterpillars only eat this plant) by pupils at Ardersier Primary School, have also played a role in making landscapes more welcoming for the species.
- Spider beach: the abandoned military site in England now ruled by arachnids
- What are insects? And how many insects are there in the world?
Tom Prescott, Butterfly Conservation’s head of conservation in Scotland, says: "We’re absolutely delighted to see the small blue having such a brilliant year in Scotland, and it’s fantastic to know our team are helping it – but it’s a complicated picture.”
Despite the success, Prescott warns that habitat loss and climate change still threaten many butterflies across the UK. Continued collaboration with landowners and communities is vital to protect these delicate species for the future.
Main image: Small blue butterfly at Balnagown. Credit: Geoff Ballinger
More wildlife stories from around the UK
- “As I got closer, I saw its tail": astonished gardener finds large animal in pond
- What’s the biggest and deadliest wasp in the world – and has it ever been seen in Britain?
- Enormous elk are recolonising Europe – and soon they could be heading for the UK
- "Unbelievable": rare killer whale encounter stuns wildlife watchers in Northumberland
