The Marsh Fritillary butterfly, once common across the UK and Ireland, has had a strong year in Northern Ireland thanks to warm weather and long-term conservation work.
Surveys by Butterfly Conservation revealed big increases in caterpillar nests on managed sites—one rising from 24 to 53, another from 24 to 139, and a third from five to 27. The species relies on a single plant, Devil’s-bit Scabious, and much of its habitat was lost due to changing farming practices.
Conservation manager Rose Cremin said weather helps only in the short term; real recovery depends on restoring and properly managing habitat with the help of farmers. Volunteers track the population each autumn by counting the communal webs where caterpillars feed and develop.
The Marsh Fritillary produces only one brood a year, making it vulnerable to habitat loss. Its range dropped 43% between 1985 and 2019, but this year’s results show that careful management can help reverse the decline.
