300 hectares of forest cleared in Wadden Sea National Park to save rare butterfly

Around 300 hectares of forest and scrub will be cleared in Denmark’s Wadden Sea National Park over the next three years to protect the endangered gentian blue butterfly, state broadcaster DR reports.

The project, covering an area equivalent to roughly 420 football pitches, aims to create open corridors between existing habitats on Rømø, Fanø, and near Esbjerg, where the butterfly’s fragmented populations struggle to survive. Heavy machinery has already begun uprooting pine trees in Kirkeby Plantage on Rømø.

The gentian blue depends entirely on the bellflower gentian plant but faces severe mobility limits—it cannot fly in strong winds, reaches only low altitudes, and typically travels no more than 400–500 meters from where it emerges. Even minor thickets can block its movement.

“Without intervention, isolated populations risk dying out,” said Conny Brandt, a nature consultant with the national park. “By connecting these areas, we hope the butterfly can spread to new sites and stabilize its numbers.”

Denmark’s gentian blue population has plummeted over the past 40–50 years, now confined to a handful of locations along the Jutland west coast and on Læsø Island. The butterfly is usually active from early July to early August.

Officials will assess the project’s impact after three years. “It’s a species worth protecting,” Brandt said. “It’s rare and iconic to our coastal heaths and the Wadden Sea.”