How the bat flap will help save endangered species

The National Trust - normally associated with the preservation of aristocratic country houses - has successfully constructed a purpose-built home for one of Britain's rarest bats.

The new roost, nicknamed the "bat flap", has been specially designed for the unusual needs of the lesser horseshoe bat which unlike ordinary bats has to be able to fly straight into its sleeping quarters rather than crawling into bed through a crevice.

In an effort to revive the fortunes of the horseshoe bat, experts have worked closely with the trust to build a summer roost with a flap on one of the gable ends of Chedworth Roman Villa in Gloucestershire.

The bat flap allows the horseshoe bats to fly straight into the roosting area inside the roof of the house without first having to land on the walls - the usual way that bats enter their roosts. "It works very much like a cat flap but it's the size of a breeze-block and covered at the sides to create a tunnel-like entrance," said Mike Collins, a trust spokesman.

After more than two years of trying to entice horseshoe bats into the new lodgings, the National Trust has at last succeeded with the establishment of a small summer colony at Chedworth. David Bullock, head of nature conservation at the National Trust, said the project was vital because the horseshoe bat has declined in numbers in recent years with the loss of suitable habitats and roosting sites.

"Without this sort of initiative the numbers of lesser horseshoe bats will continue to decline as they struggle to find suitable roosts and habitats," Mr Bullock said. "Bats are one of the key species for the National Trust and we are working to make sure that our buildings can effectively support colonies of them and other species throughout England, Wales and Northern Ireland.".

The lesser horseshoe bat can live more than 20 years and usually lives in summer colonies of between 30 and 70 individuals. They mate between September and November and give birth to one offspring in the following mid-summer.

During winter they live in caves, mines and tunnels and at the end of hibernation they move to roofs of larger houses and stable blocks - but they need to fly directly into the roosting area.

Horseshoe bats were once found throughout southern England and Wales but the entire population of about 14,000 individuals is now confined to the South-west, with Gloucestershire at the heart of its current range.

Mr Collins said the trust had been working to create environments that allowed horseshoe bats to live and breed undisturbed. They live on flies, moths and spiders and need joined-up hedgerows and lines of trees to create feeding habitats.

The Chedworth project is part of a wider range of initiatives which are designed to help and encourage bats to breed. Chedworth already has established colonies of more familiar bats such as pipstrelle and whiskered bats.

Chedworth Roman Villa in the Cotswold countryside is the oldest stately home run by the National Trust, dating from the 4th century AD. The trust organises special "bat walks" in the grounds of the house during summer evenings.