A £20,000 upgrade to a Carmarthenshire nature reserve is helping the ponies help the cows to help one of the UK’s rarest butterflies.

National charity Butterfly Conservation has carried out improvements works at its Caeau Ffos Fach reserve north of Swansea.

A local contractor put up 900 metres of fencing, installed three water troughs, and removed 2,000 square metres of brambles and gorse, all to help the delicate and rare Marsh Fritillary which has almost disappeared across the UK.

Butterfly Conservation’s Head of Conservation for Wales, Alan Sumnall, said: "A huge amount of work has gone into transforming the site and it means we can target the grazing of the cows and ponies much better than before – it’s fantastic to see the difference it’s making already."

Although the £20,000 funding from Natural Resources Wales will ultimately benefit the Marsh Fritillary, the works have actually revolved around a pretty purple flower with a striking name: Devil's-bit Scabious.

Scabious is one of the only plant that Marsh Fritillary caterpillars eat, and the best machines for helping Scabious are cows and ponies.

By eating grass and trampling areas to bare soil - known as 'poaching' - the animals replicate the actions of large prehistoric herbivores that once roamed the UK, such as aurochs, and create space for the Scabious more effectively and naturally than humans can.

Alan explained: "The Marsh Fritillary is a beautiful little butterfly - it's got orange-and-black chequered wings like stained-glass windows, a furry body and striped antennae with little clubs on the ends. It used to be widespread across Britain and Ireland but its distribution plummeted more than 40% since 1985. In Wales alone its abundance has dropped 60%.

"The main problem is habitat loss - farming practices have changed and we've built over a lot of land, which is why it's now one of our highest-priority species. Thankfully, we know exactly how we can help, and at the sites where we're able to work with farmers and other partners to create the right habitat we're getting fantastic results."

Caeau Ffos Fach, part of the Mynydd Mawr Special Area of Conservation, is now one of the last Marsh Fritillary strongholds.

Butterfly Conservation leases part of the site from Natural Resources Wales, and Carmarthenshire County Council helps with the management.

The charity also works with local grazier Paul Hughes to graze his cattle on the site each summer, followed by ponies over winter.

In recent years the old fences had started falling apart, running the risk that animals could escape, and there was only one water trough for four of the fields which meant the animals naturally stayed in that corner of the site leaving the rest to get overgrown. Tough grass, bramble and gorse had taken over in places, leaving no room for Scabious.

The new fences, put up in the spring, divide the site into four sections, each with its own water trough - fed by 300 metres of new pipes, so Alan and his team can now target where the cows and ponies graze.

The expert contractor also mowed four hectares of tough grass that the cows wouldn’t eat and removed 2,000 square metres of scrub, opening up huge new areas where the animals can now graze to their hearts’ content.

Alan said: "We’d like to say a massive thanks to Natural Resources Wales for the funding, Carmarthenshire County Council for their support, our contractor for doing a brilliant job, and to our grazier Paul for his fantastic partnership.

“We also want to say thank you to the amazing volunteers who also help us maintain this site and, crucially, count the Marsh Fritillaries each year so we can prove that, with the right management, we can benefit a local agricultural business and help a wonderful rare species at the same time."

Carmarthenshire County Council conservation officer Amanda Evans said: "This project has been a really good team effort between Butterfly Conservation, NRW and CCC, and shows the importance of partnerships in conservation work. Butterfly Conservation has always been a great support to the Caeau Mynydd Mawr project and I was glad to be able to help with this work which will be so beneficial to the management of the reserve. "

Jen Day, Conservation Officer at Natural Resources Wales, said: "Through the management agreement with Butterfly conservation, Natural Resources Wales have funded conservation restoration works of Caeau Ffos Fach SSSI which is part of the Mynydd Mawr SAC.

“This restoration works funded from the Nature Network Fund will improve the conservation status of the designated features of the site which is marshy grassland and the Marsh Fritillary butterfly. With thanks to the collaborative working with Butterfly Conservation and Carmarthenshire County Council to achieve this, we hope to continue with restoration works and see favourable conservation status of the site in the future."

Find out more about the Caeau Ffos Fac reserve and how to visit at butterfly-conservation.org/our-work/reserves/caeau-ffos-fach-cross-hands-carmarthenshire

Find out more about the Marsh Fritillary at butterfly-conservation.org/butterflies/marsh-fritillary