UK’s rarest bats found in Wiltshire woodland

'To find them all in one wood is impressive'

October 2010: Four of the UK's rarest bats have been found in privately-owned Wiltshire woodland. The Bechstein's, Barbastelle, Lesser and Greater Horseshoe bats were found in this patch of the Braydon Forest, in Minety, near Malmesbury during radio tracking surveys carried out jointly by the Wiltshire Wildlife Trust and the Cotswold Water Park Society's CWP Bat Initiative.

RARE: A Bechstein's bat. Picture: Gareth Harris / WWT

‘Over four nights we went out with a team of volunteers from the CWP Bat Initiative and spent many hours setting up equipment, catching bats, fitting radio tags and tracking them. We also used special recording equipment to help identify bats which otherwise would have remained undetected,' says Paul Darby, the trust's Landscapes for Wildlife Project Officer.

Gareth Harris, Biodiversity Officer of the CWP Society, says: ‘These four bats are listed on the IUCN Red List and are the only bats in the UK to have European-level protection, so to find them all together in one wood is deeply impressive. It is estimated that there are only 1,500 Bechstein's in the UK.'

Thirteen different species of bat in one wood

And that's not all they found. A total of 13 bat species were discovered feeding in the wood (out of 18 that breed in the UK) - the full quota of bats known to live in Wiltshire. And this is likely to be just the tip of the iceberg because the team has only just begun bat surveys of the Braydon Forest and wider area.

‘For all we know there could be a colony of Bechstein's in every wood in the area - or this is the only one? What else is out there? So please, if you have bats of any species in your house or using your barn, get in touch with us at the trust,' says Paul.

So what makes the Braydon Forest so special for the bat world? Gareth explains: ‘It has a fantastic network of woods, big bushy hedges and grassland. There are plenty of places to roost in the woods and old buildings. The meadows provide good foraging habitat for the bats, and the hedges act as bat motorways, allowing them to commute around the area.'

The team used nets positioned among the trees to trap the bats and then carefully attached the tiny radio transmitters (only 5mmx2mm in size) to three Bechstein's. The tags last up to 14 days before the battery runs out, but in this case were groomed off or fell off after six nights at the most.

They seem to be breeding

Gareth says: ‘We were lucky that the Bechstein's bats led us to a colony of at least 12 females; the fact that we have caught lactating females indicates that they are breeding here, too. We only know of one other in Wiltshire - in the Wiltshire Wildlife Trust's Green Lane Wood nature reserve near Trowbridge.'

At least one bat flew to another nearby wood a kilometre away, hinting that Braydon Forest woodlands may hold several colonies of Bechstein's bats. This sort of knowledge is invaluable when planning any woodland management and bat conservation work.

Whereas bats are generally more abundant on the Continent, in the UK woods have often become too small or too fragmented and isolated, or are simply not well-managed for wildlife, points out Gareth. The loss of regular woodland management such as coppicing has had an impact on a range of woodland birds, dormice and some species of bats.

Wiltshire Wildlife Trust and the Cotswold Water Park Society are working together on a number of sites, for example trust nature reserves such as Ravensroost Wood, Clattinger Farm and Sandpool Farm, studying bats and other species using them.

The Cotswold Water Park Bat Initiative was launched in 2005 to promote the study of bats across the CWP, supported by a large number of local volunteers who have completed vast numbers of surveys, monitored numerous roost sites, spent many nights radio tracking them and constructed new roosts designed specifically for bats.