Arctic Wave Dancer: One of Britain’s rarest fly species discovered at Scottish nature reserve 

One of Britain’s rarest fly species has been discovered at Scotland’s largest nature reserve. 

The endangered fly species, known as the Arctic Wave Dancer for its lochside courtship displays, is found on just three sites in the Cairngorms and nowhere else in the UK.

The National Trust for Scotland team are celebrating after the threatened fly species was discovered at Mar Lodge Estate National Nature Reserve.

This tiny ice age relic can only develop in cold, deep, and pure water, making the Cairngorms’ high-altitude lochs a suitable home for the species. 

During its short adult life span in the summer months, it can be found clinging to the verges of rocks and displaying its unique courtship dance and waterproof abilities against the waves lapping against lochside boulders. 

A search for the species by entomologist Iain MacGowan from National Museums of Scotland, and NTS in July 2024 found the Arctic Wave Dancer dancing on the edges of Lochain Uaine and its granite boulders, 950m high in the shadow of Ben Macdui, where it has never been recorded before.

The three lochs in the Cairngorms, two of which are on the conservation charity’s Mar Lodge Estate, are the only known sites for the Arctic Wave Dancer in the UK, with its next nearest populations in the arctic regions of Finland, Norway and Russia. 

The species was initially rediscovered by Iain at Loch Avon in 2018 and in 2020 it was discovered for the first time by him at Loch Etchachan on the Mar Lodge Estate.

‘Although it’s small, this fly is of enormous importance to the Cairngorms and the wider British Isles,’ Iain said.

‘Living on only a few of the high-altitude lochs, it is on the front line when it comes to meeting the challenge of climate change. 

‘Finding it at its highest-level site, 950m at Lochan Uaine, will hopefully ensure that the populations will be better able to withstand the effects of a warming climate. 

‘We must continue to monitor this iconic species and carry out further surveys of other potential sites.’

Due to the specific cold water temperatures required for the species to thrive, the Arctic Wave Dancer is one of the species most at risk from climate change and is a top research priority species for NTS.

‘The Arctic Wave Dancer lives in about as remote and challenging an environment as you can find in Scotland, so finding it at a new site was a wonderful surprise, and is a testament to the hard work and skill of dedicated entomologists like Iain MacGowan,’ Andrew Painting, NTS Conservation Officer at the Mar Lodge, said.

‘Our charity is responsible for protecting the nature in our care and the discovery of one of Britain’s rarest species at Mar Lodge Estate is evidence of nature’s resilience and the importance of our conservation work.

‘Every species we protect is a step towards safeguarding Scotland’s nature, beauty and heritage for everyone.’

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