Trial to control bracken brings benefits for the UK’s most endangered butterfly

The James Hutton Institute is marking Butterfly Education and Awareness Day this Saturday (7th June) with its pioneering work that is helping to improve the habitat of the UK’s most endangered butterfly, the High Brown Fritillary.

The Hutton is at the forefront of research to mitigate the effects of the climate and nature crises that threaten our ecosystems. It offers scientific solutions for the sustainable management of our natural resources and the conservation of our species and habitats.

The High Brown Fritillary is present on one of the farms taking part in a trial by Innovative Farmers, “Managing bracken with livestock and associated environmental outcomes”, using animals instead of chemicals to control bracken.  Cattle, pigs and ponies are encouraged to enter areas of bracken with methods such as strategically placed hay or salt licks. By trampling the bracken using their natural body weight, they open up space for other plants to grow, including dog violets, that are a key food source for caterpillars of fritillary butterflies.

Field lab researcher Robin Pakeman of The James Hutton Institute, who is monitoring changes to habitat for the project said: “This is a great opportunity – we haven’t had a trial like this for decades. Asulox herbicide used to be sprayed over large areas and, if followed up properly with repeat spot spraying, could be very effective. However, it is no longer available, so we have to think differently. Using livestock means we can hopefully manage with more precision to achieve different impacts across a stand of bracken. We’re monitoring the trial closely and hoping for a long-term boost for biodiversity.”

Left unmanaged, bracken can spread across grazing land and outcompete important ground flora. If it is too dense it threatens the habitat of the High Brown Fritillary. The trial aims to maintain a balance and mosaic of habitats providing opportunities for a range of biodiversity. 

“This is a great opportunity – we haven’t had a trial like this for decades. Asulox herbicide used to be sprayed over large areas and, if followed up properly with repeat spot spraying, could be very effective. However, it is no longer available, so we have to think differently.”

Robin Pakeman, The James Hutton Institute
The UK’s most endangered butterfly, the High Brown Fritillary
The UK’s most endangered butterfly, the High Brown Fritillary

Butterflies are highly sensitive indicators of the health of the environment and play crucial roles in the food chain as well as being pollinators of plants. The wildlife charity, Butterfly Conservation has reported that half of Britain’s remaining species are threatened with extinction.

For more information, contact Media Officer, Joyce Reid, joyce.reid@hutton.ac.uk or on 07931 551 988