One of Northern Ireland's rarest butterflies has had a reassuringly good year.
Staff and volunteers at Butterfly Conservation monitor the population of Marsh Fritillaries each autumn by counting the silken nests its caterpillars weave in long grass, known as larval webs.
In September, two staff and 13 volunteers in Northern Ireland counted 679 webs across 20 sites, a reassuring increase on the 423 counted in 2023.
However the species is still highly vulnerable and Butterfly Conservation is now calling for more appropriately-managed sites, especially farmland, to help it spread its wings.
Butterfly Conservation Northern Ireland Conservation Manager Rose Cremin said: "I love doing these surveys - you get to see these beautiful and rare insects and so much other nature and wildlife thriving on these sites.
"This year's results are a good sign that our work to protect habitats is delivering, now we need the government to continue to reward farmers for farming with nature.”
The Marsh Fritillary, a striking butterfly with orange, yellow and brown chequered wings, was once so common in Northern Ireland that in the 1850s farmers recorded fields swarming with caterpillars in the autumn.
However, like many other butterflies, numbers have plummeted throughout the 20th century.
In September, Butterfly Conservation declared a Butterfly Emergency to draw attention to decades of devastating declines, and called on the UK Government to ban the use of neonicotinoid pesticides.
Marsh Fritillary caterpillars almost exclusively eat the leaves of Devil's-bit Scabious, but both this plant and the butterflies have been battered by habitat loss and changes in agricultural land management.
Between 1985 and 2019, the number of sites where Marsh Fritillaries could be found in the UK dropped 43 per cent.
The species has also declined across Europe, making Britain and Ireland an important stronghold.
In Northern Ireland there are still a number of areas where the species can be found and Butterfly Conservation receives funding from the Northern Ireland Environment Agency to help monitor and advise on the species.
The charity also relies on volunteers to help carry out surveys and is keen to recruit more locals to help count the larval webs each autumn.
Rose explained: "If you find a site with caterpillars you know it's a breeding site, which is crucial for the long-term conservation and survival of the species. We can return each year and gather data to help determine the status and distribution of these butterflies, while also giving land management advice.”
Thanks to growing awareness, improving habitat management and site protections such as Area of Special Scientific Interest (ASSI), Butterfly Conservation now classes the species as stable but still declining in Northern Ireland.
The good numbers this year are likely down to a combination of appropriate site management and a short window of dry, clement weather in June - but in order to help the species really recover in the long-term the charity is calling for more support for protected sites and priority habitats.
Rose said: "Our goal is to not only protect and stabilise the populations that we have left but to make landscapes bigger, better and more joined-up. We need to continue to raise awareness of how special and rare these species and habitats are by engaging with farmers and land managers, supporting and advising government agencies and departments in developing nature recovery networks and connecting people to nature.
“We urge the government to put more money into agri-environment schemes aimed at not just maintaining but increasing the grassland habitat which can provide a home for Marsh Fritillary and a host of other species.”
NIEA spokeswoman Pauline Campbell said: “NIEA would like to acknowledge the valuable survey effort Butterfly Conservation and volunteers have invested in Marsh Fritillary monitoring. It is brilliant to see this beautiful species thriving this year. Northern Ireland has a network of sites designated as ASSI’s to support Marsh Fritillary through careful management their preferred habitat.
“The continued management of our species-rich grasslands which support species such as Marsh Fritillary is also delivered through agri-environment scheme such as Environmental Farming Scheme. EFS supports farmers and land managers to carry out environmentally beneficial farming practices.”
To find out more about volunteering opportunities with Butterfly Conservation in Northern Ireland email [email protected]
