A tiny butterfly hiding in plain sight in southern Alberta has been identified as a new species, ending decades of mistaken identity.
Once thought to be part of the half-moon hairstreak group, the insect found only on the Blakiston Fan in Waterton Lakes National Park has now been officially named the curiously isolated hairstreak (Satyrium curiosolus).
The newly recognized species has been evolving separately from its relatives for roughly 40,000 years, according to a study published this week in ZooKeys.
Researchers say the discovery sheds light on the powerful role of isolation in shaping biodiversity — and raises urgent conservation concerns due to the butterfly’s genetic fragility and extremely limited range.
“This butterfly is a powerful example of how long-term isolation shapes biodiversity,” said Dr. James Glasier, Conservation Population Ecologist with the Wilder Institute.
“But its rarity and extreme specialization also make it incredibly vulnerable — there’s no fallback population to sustain its survival.”
The finding comes from a collaborative effort involving the Wilder Institute, Parks Canada, and scientists from the University of Alberta, the University of Kentucky, and UCLA. Genomic and ecological data confirmed that the curiously isolated hairstreak has no recent contact with other populations of hairstreak butterflies, which are typically found in sagebrush habitats across British Columbia and Montana.
Instead, this new species is tied to a distinct ecosystem. It depends exclusively on silvery lupine (Lupinus argenteus) as a host plant and has a unique relationship with a local ant species (Lasius ponderosae), a partnership unseen in other hairstreak butterflies.
Though seasonal butterfly counts range from 2,200 to 13,000 adults, scientists say the population’s long-term prospects are threatened by “genomic flatlining.” With an effective population size of only about 500 and extremely low genetic diversity, the butterfly may struggle to adapt to environmental shifts driven by climate change.
Because the species is so genetically unique, traditional conservation tools like cross-breeding or translocation are off the table. Instead, site-specific conservation strategies are needed to protect the Blakiston Fan’s fragile ecosystem, including tackling threats like the spread of invasive plants such as spotted knapweed (Centaurea stoebe).
Monitoring programs led by the Wilder Institute and Parks Canada are already underway, and scientists stress the importance of continuing this work to safeguard the butterfly’s future.
The discovery underscores the power of genomics to uncover hidden biodiversity and emphasizes the role of research and conservation partnerships in preserving Canada’s natural heritage.