By Andrew Woodger
The silver-studded blue has distinctive metallic spots on its hindwings
Exmoor ponies are to be introduced to graze a Suffolk heath for the benefit of a rare butterfly.
Suffolk Wildlife Trust volunteers have been clearing Blaxhall Common of scrub to allow heather to thrive.
Silver-studded blue butterflies, which breed among the heather, were re-introduced there in 2007.
Four ponies should reduce the number of silver birch saplings, but leave heather and mosses which are favoured by a variety of rare insects and birds.
"Because the silver-studded blue had a history of being here, we thought it was important to bring it back," said David Mason, Suffolk Wildlife Trust's sandlings manager.
"It's lovely. It's a blue colour and the little silver specks really shimmer in the sunlight."
The 40 hectare/100 acre site is owned by Blaxhall Parish Council and managed by the wildlife trust.
Historically, it's 'common land' which meant people had a right to use it for gathering firewood, grazing sheep, picking heather for thatching or animal bedding, and using sand and gravel for roads.
David Mason has been working at Blaxhall Common for 15 years
"Every stick and stone had a use," said David. "But that fell into disuse and consequently the whole area grew with silver birch trees, scrub and bracken and it was turning into woodland.
"We came in to try and preserve the rare habitat and the species that live on it by starting to clear the scrub and bracken again.
"Without the light getting to the ground, the heathers and grass that are special to the area can't survive."
In 2007, the silver-studded blue butterfly was reintroduced to Blaxhall, after a 60 year break. Sixty butterflies were caught on sites in nearby Minsmere and Hollesley and brought over.
However, in the butterfly stage, they only live for around five days during June and July, so the window of opportunity for mating is narrow.
The butterfly doesn't travel more that a mile (with a good wind!), so the fragmented nature of heathland sites makes it harder still. Blaxhall is five miles away from the nearest colony.
In 2008, 15 were recorded, while in 2009 that had increased to 19, which provided evidence that breeding was taking place.
The silver-studded blue and the common ant rely on each other for survival using a form of 'mutual aid'.
The ants eat the sweet secretions of the caterpillar and therefore protect the eggs by dragging them underground for the winter and defending them from attack until they turn into butterflies in the spring.
Even when they're emerging from the ground, the ants will cover and protect the butterfly until its wings dry out.
"The butterfly has obviously learnt that by secreting this substance that the ants will be attracted to it and they will protect it," said David.
"Other butterflies, such as the large blue, eat the larvae of the ants, so that's a bit of a parasitic relationship."
Emily Deacon from Natural England's regional office in Bury St Edmunds
Natural England funding
Suffolk Wildlife Trust gets £8,500 a year from the government's Natural England body for its work at Blaxhall.
Emily Deacon is Natural England's Higher Stewardship Scheme advisor:
"Our aims are increased biodiversity, nature conservation, public access and our big scheme at the moment is environmental stewardship.
"Farmers and land managers can get funding to do this work.
"I'm absolutely thrilled with all the work that's been done here. They've done a great job.
"The site's really improving and you can see that by the rare bird species of nightjar, woodlark and dartford warbler.
"There are also red-banded sand wasps and ant lions because of the amount of bare ground which is warm and suitable for them to dig down into."
Exmoor ponies in Exmoor National Park in the west country
There's a team of three staff members using chainsaws, mowers and other machinery supported by an army of work-party volunteers clearing the scrub on their hands and knees in all seasons.
They've cleared around five hectares in the past three years.
"They're coming out with a group - it's the camaraderie and the feeling that you're doing something for wildlife that's the important part of it," said David.
And there's also a group of four-legged volunteers - the team of four Exmoor ponies will arrive in May 2010 in a part of the site surrounded by an electric fence.
"It prevents the cycle of re-growth of birch and pine seedlings. Hopefully the ponies will munch away and keep the re-growth in check," said David.
"They will eat the heather, but some grazing is good because it keeps it short and creates a mosaic of different types of growth."
Blaxhall Common is free to enter, but dogs should be kept on leads to protect birds which nest on the ground.
For volunteering and visiting information visit the
Suffolk Wildlife Trust
website or ring 01473 890089.
A report on the project will be on Steph Mackentyre's breakfast show on Saturday, 24 April, 2010 on BBC Radio Suffolk.