The rare Marsh Fritillary butterfly has seen a strong boost in Northern Ireland after years of decline, thanks to warm weather and targeted conservation work.
Butterfly Conservation reported major increases in caterpillar nests at managed sites—one farm saw numbers rise from 24 to 53, while another jumped from 24 to 139. The species relies on a single plant, Devil’s-bit Scabious, which grows in well-managed grassland often grazed by cattle.
Conservation manager Rose Cremin said good weather helps, but long-term success depends on restoring and maintaining proper habitat. Volunteers survey sites each autumn by counting the silken webs where caterpillars feed and hibernate.
The Marsh Fritillary produces only one brood a year, making it vulnerable to habitat loss. Despite past declines of more than 40%, this year’s results show promising recovery thanks to sustained conservation efforts.
