The rare Marsh Fritillary butterfly has had a strong year in Northern Ireland, thanks to warm weather and long-term conservation efforts. Once common across the UK and Ireland, the species declined sharply as farming practices changed and key habitats disappeared.
Surveys of caterpillar nests show major increases on managed sites—one rising from 24 to 53 nests, another from 24 to 139. Butterfly Conservation credits close work with farmers to restore and manage grassland where the butterfly’s only food plant, Devil’s-bit Scabious, can thrive.
Conservation manager Rose Cremin said good weather helps but cannot reverse decades of decline without proper habitat management. Volunteers survey sites each autumn by counting the silken communal webs built by caterpillars, giving a clear picture of population health.
With the Marsh Fritillary producing just one brood a year, habitat loss makes it highly vulnerable. Although the species’ distribution has fallen by 43% since 1985, this year’s results show that focused conservation action can lead to real recovery.
