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Page last updated at 16:41 GMT, Thursday, 14 April 2011 17:41 UK
A dragonfly's guide to Britain

By Emma Brennand
Earth News reporter


A schwingmoor bog is thriving with rare White-faced Darter dragonflies

The sheer cliffs of rock and murky deep waters of a quarry are not the ideal location to raise a family.

But in modern Britain wildlife is thriving in the most unexpected places.

Up and down the country thousands of gravel pits, quarries and opencast mines are being flooded to create prime real estate for wildlife.

Dragonflies in particular are thriving in these roughly carved wildlife havens.

Since the 1980's warmer temperatures have allowed many of the UK's dragonflies to expand their range northwards with five new species arriving on our shores from the warmer climates of southern Europe.

The White-faced Darter
Britain is home to 24 dragonfly species

"In 2007, the Willow Emerald was discovered, its populations are now being monitored and there may well be established breeding populations," Claire Install, conservation officer for the British Dragonfly Society told BBC News.

"Also the Dainty Damselfly had been declared extinct in the UK after floods in the winter of 1952/53, but was rediscovered in Kent last year."

This migrant species was followed by others in 2010 including the Southern Migrant Hawker, Southern Emerald Damselfly and Vagrant Emperor.

Many species with a primarily Mediterranean distribution in Europe are known to now be advancing northwards.

The Small Red-eyed Damselfly is now a common breeding species in much of south-east England. It first appeared in Britain in 1999 and has flourished since.

Bog-loving dragons

However, some native dragonflies may not be faring so well.

Habitat loss and a changing climate are contributing to falling numbers and many local councils have developed biodiversity action plans to help stabilise this decline.

In particular, populations of bog-loving dragonflies are declining as they find their wetland habitats shrinking.

But this is where a dragonfly's love of rocky, water-filled places can be exploited.

The White-faced Darter, named after its white "nose", is one of Britain's rarest dragonflies found to breed at only five sites in the England.

It has been lost from half of its English sites in the last 50 years.

Dragonflies love wet places as their nymphs remain aquatic for months or even years
Adult dragonflies have two sets of wings and can fly in any direction

In 2010, conservationists from the Cumbria Wildlife Trust, British Dragonfly Society and Natural England began a trial reintroduction project at Foulshaw Moss Nature Reserve in Cumbria.

Buckets of the Sphagnum moss, amongst which the larvae of the White-faced Darter live, were collected from a donor site in north Cumbria and transported to Foulshaw Moss Nature Reserve.

This mix of moss contained eggs and two generations of larvae of the White-faced Darter.

It is hoped that these young dragonflies will develop into adults and further colonise the myriad of pools found on the site. This is the second reintroduction of a dragonfly species, the first being the relocation of the Southern Damselfly to Venn Ottery nature reserve in Devon.

It will be interesting to see if any White-faced Darters emerge at Foulshaw Moss nature reserve in 2011. The reintroduction programme at Foulshaw Moss is set to continue for a further two years.

Sphagnum sanctuary

Chartley Moss National Nature Reserve in Staffordshire, which lies at the most southerly point of the White-faced Darter's range, offers the insect one of the best habitats in the UK.

The unusual geology of the Staffordshire reserve has helped form a unique underground lake shrouded by a raft of sphagnum. The site is the UK's largest example of an unusual floating peat bog called a schwingmoor. The underground lake is up to 16 metres deep and is covered by a metre of sphagnum, creating a sphagnum raft.

"The bog was formed by dissolving salt deposits in underlying rocks creating a large hollow which was then in filled by ground water. Creating an underground acidic lake," explains Mel Brown, reserves manager for Staffordshire's National Nature Reserve.

"The White-faced Darter is especially fussy and seeks out acidic waters. So Chartley Moss is perfect."

Dragonfly larvae in pond
Dragonfly larvae have a double hinged jaw to impale prey

The sphagnum provides cover for the larvae from predators such as other dragonfly larvae.

The bog pools are too acidic to support fish populations allowing insects to thrive, whilst the emergent vegetation around the pools allows larvae to climb up before the adult dragonfly emerges from the larval case, or exuvia.

The population at Chartley Moss National Nature Reserve has increased in recent years due to careful management of the bog by Mel Brown and her team of volunteers. Pine trees and birch scrub have been cleared to stop forests developing and steps have been taken to help raise the water table levels.

Join the BBC Animal's Guide to Britain team tonight as they visit Chartley Moss to reveal how these changes in habitat have sculpted the lives of British dragonflies.

The Animal's Guide to Britain is broadcast on BBC Two on Thursday 14 April at 20.00BST.

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