Butterflies Help Monitor Welsh Peat Bogs' Climate Fight

An endangered butterfly might become our newest ally in the fight against climate change, thanks to an innovative conservation project taking place across the wetlands of Wales.

Georgina Paul of Butterfly Conservation is halfway through a groundbreaking two-year study investigating whether the large heath butterfly can serve as a reliable indicator of peat bog health. These unusual ecosystems store massive amounts of carbon when they stay wet, but climate change threatens to dry them out and release greenhouse gases back into the atmosphere.

The large heath butterfly only survives in healthy peat bogs because its caterpillars eat a single plant that grows nowhere else. That makes these chestnut-colored butterflies with striking black spots perfect candidates for monitoring the condition of these critical wetlands.

Since last year, Georgina has been counting butterfly populations across hundreds of square kilometers of protected Welsh peatlands, from Cors Caron near Tregaron to the Berwyn Range in the northeast. The study runs until May 2027 and covers all protected areas where the species still exists.

The Ripple Effect

If the research proves successful, the impact could extend far beyond butterfly counting. Volunteers without technical expertise could conduct simple butterfly surveys each summer, providing invaluable data about peatland health without expensive equipment or specialized training.

Wales contains roughly 90,000 hectares of peatland covering 4% of the country's land area. When healthy and waterlogged, these bogs lock away carbon, support rare wildlife, improve water quality, and reduce flood risks. The Welsh government recognizes this potential, awarding £249,000 in lottery-funded support to the project.

The study focuses largely on sites where restoration work has already rewetted dried peat bogs, allowing Georgina to identify improvements in butterfly habitat. The project is even testing drones to map peat bog vegetation and speed up habitat assessments.

The challenges remain significant, with some monitoring sites lacking records for 25 years and much of the land sitting in private hands. But Georgina embraces the work with enthusiasm, ready to visit sites five days a week when summer weather allows.

"Peat bogs are weird and wonderful places with fantastic wildlife," Georgina explains. "But looking after them well will also help us tackle the global challenge of climate change by keeping carbon in the ground."

The large heath butterfly has declined dramatically across England and Wales during the past century due to habitat loss and is now listed as endangered. This project could help reverse that trend while simultaneously protecting the wetlands these delicate creatures call home.