This Whiskered Bat was found during a recent survey in the Forest of Dean
A team of volunteers from the Gloucestershire Bat Group is carrying out a survey of rare Bechstein's bats in the county.
The research is part of a national survey led by the Bat Conservation Trust, which aims to systematically check all of southern Britain.
The UK is right on the northern fringes of the habitat for this extremely rare species, which lives mainly in woodland.
David Priddis, chairman of Gloucestershire Bat Group, who is one of the coordinators of the survey, said the project has so far produced very few specimens locally:
"So far we haven't been doing very well [with capturing Bechstein's bats this summer].
"We've caught one Bechstein's bat [at Westonbirt Arboretum].
"We've got very, very few summer records of them and we don't really know where they breed and how far distributed they are, but we do have records of them in the Forest of Dean and in Gloucestershire generally."
In the autumn, at a site near Cinderford, the team caught eight different species of bats, including 22 Bechstein's in one night.
"They do what's described as "swarming" where a lot of different species of bats go to particular caves and mine sites," said David.
A harp trap was used to catch the bats
"They all fly around the entrance and inside, and they come out often covered in mud. We don't know why but we assume it's something to do with mating behaviour.
"We think that some of those bats have come up to 20km to get there. It really is a complete mystery."
During a recent night's surveying in the Forest of Dean the group managed to capture and identify a Whiskered Bat, but so far no other Bechstein's have been found.
The bats are lured into a harp trap - a frame covered with wires, like a harp, that captures the bats as they fly - using ultrasonic social calls broadcast from a system developed at the University of Sussex called 'the Sussex Autobat'.
Thirteen Bechstein's bats have been found this summer across seven counties as part of the national survey.