[Pollinator] Large blue butterflies doing well in UK

[Kimberly Winter]

UK's Large Blue butterfly populations are doing better than ever:

http://news.bbc.co.uk/2/hi/science/nature/5385488.stm

Also notable is their amazing relationship with a species of red ant that 
"adopts" them.

~Kim

--> Join us on October 18th for the POLLINATOR PARTNERSHIP Symposium at the 
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Kimberly Winter, Ph.D.
International Coordinator
North American Pollinator Protection Campaign
Internet: www.nappc.org, www.pollinator.org
Ph: (301) 219-7030

Successful summer for large blue
By Mark Kinver
Science and nature reporter, BBC News



The large blue butterfly disappeared from the UK in 1979


Enlarge Image

UK conservationists are celebrating a successful summer for a rare 
butterfly, which went locally extinct in 1979.

An estimated 10,000 large blue butterflies have been recorded at sites 
across southern England - the largest number for at least 60 years.

Efforts to rebuild the population have been underway since 1983, when 
Swedish caterpillars were introduced to the UK.

Experts hope the project will show that such programmes can help other 
species threatened with extinction.

More than 150 scientists, conservationists and volunteers have been involved 
in the Large Blue Project, a partnership of 11 organisations, co-ordinated 
by the Centre for Ecology and Hydrology.

Dave Simcox, manager of the project, said there was still more work to be 
done.

"Whilst one landscape in Somerset is reasonable secure, the real challenge 
is to replicate this success throughout the Cotswolds, South Devon, and the 
Atlantic coasts of Devon and Cornwall," he explained.

Dr Nigel Bourn, director of species conservation at Butterfly Conservation, 
said it offered hope for other threatened species.

"Given the proper resources, we can restore a countryside full of 
butterflies and other wildlife," he said.

Ant 'adoption'

In the 1970s, scientists discovered that the reason why the large blue 
(Maculinea arion) became locally extinct was a result of changes to the way 
the rural landscape was managed.

Jeremy Thomas, from the Centre for Ecology and Hydrology, Dorset, found that 
the survival of the butterflies was closely linked to a particular species 
of ant.

Professor Thomas observed that up to five species of red ants would "adopt" 
a large blue caterpillar, but the butterfly would only survive in the nest 
of one - the Myrmica sabuleti red ant.


The butterflies are dependent on the Myrmica sabuleti red ant (Image: Jeremy 
Thomas)

He said changes to farming practices were behind the demise of the ants, 
which in turn caused the large blue butterfly to disappear from the UK.

"The old-fashioned pastoral grazing of unfertilised downlands and valleys 
was abandoned by farmers over a period of many years," Professor Thomas 
said.

"The butterflies need this tight grazing because the shorter the grass is, 
the warmer the soil. And the particular ant needed by the large blue thrives 
in very warm soil."

He added: "It all came to a head in the 1950s onwards because for many years 
wild rabbits had filled the void left by the removal of the sheep and cattle 
from the land.

"But then there was an outbreak of myxomatosis in the mid-50s and there was 
nothing left to graze these sites.

"All the sites became overgrown and the soil became too cool, and the one 
species of ant the butterfly needed declined," he added.

As part of the reintroduction programme by the conservationists, grazing was 
re-established on the sites chosen for the butterflies.

"Very quickly, the ants spread from the little pockets where they had been 
surviving and became widespread," Professor Thomas said.

Thyme, the herb on which the large blue laid its eggs, was also planted at 
the sites.

The locations were then constantly monitored to ensure conditions remained 
suitable for both species.

Public access


Conservationists are hopeful numbers will increase (Image: Dave Simcox)

The only site in the UK that actively encourages the public to come and see 
the butterflies is on Collard Hill, Somerset, which is managed by the 
National Trust.

Matthew Oates, a butterfly expert for the Trust, said the location has had 
about 4,000 visitors since it opened to the public in 2002.

"We worry a little bit about trampling damage, and disturbance to egg-laying 
females," Mr Oates said.

"But the really good thing we have found is there is a wide diversity of 
people coming to visit, including families, locals and people who are not 
naturalists but are interested in seeing something rare and special."

The partnership's reintroduction programmes are funded by the wildlife 
watchdog English Nature, which is to be merged with a new organisation, 
Natural England, in October.

Despite the successful summer, the butterfly remains on the international 
list of endangered species, and is part of the UK's Biodiversity Action 
Plan.