Barbastelle Bat Project

Woodland bat research on Dartmoor

A challenging research project to look into the distribution, numbers and feeding habits of the rare barbastelle bat on Dartmoor has come to an end in 2010. A partnership of Dartmoor National Park Authority, the Woodland Trust (external link, opens new window)and the National Trust, (external link, opens new window) with funding from the SITA Trust, (external link, opens new window) through the Landfill Communities Fund, set up the £25,000 research project in 2007 to shed light on the ecology of one of the rarest British mammals.  It employed a PhD student to trap and track these elusive creatures in wooded Dartmoor river valleys.  

The first breeding colony of barbastelles on Dartmoor had been found in 2002 in Dendles Wood National Nature Reserve.  Barbastelles are a priority species for conservation under the UK Biodiversity Action Plan.  There are thought to be only about 5,000 barbastelle bats in the UK but the exact status and distribution is unknown. During the project, 19 barbastelles were tracked and two new breeding colonies were discovered in the Bovey and Dart Valleys.  The research found that the bats mostly foraged within 8km of their roosting area, although one individual traveled as far as 20km to its favored feeding ground.  They preferred to feed over riverside and broad-leaved woodland, species-rich grassland and hedgerows. The Dartmoor bats seem to strictly divide their feeding areas between individual bats, which may explain why they are so ‘thin on the ground’

The first ever recorded Bechstein’s bat for the National Park has also been discovered in the Dart Valley - one of the rarest mammal species in the UK, with only 1,500 individuals estimated! The nearest record of Bechstein’s bats to date was made in October 2007 near Newton Abbot. Three animals (a female and two others) were discovered in the roof of a house – a very unusual place for a secretive woodland bat.  In 2006, no Bechstein’s bats were found in the National Park, despite an intensive expert search effort over a period of two weeks.  It is possible that with the warming climate, this southerly species is spreading further west and to higher altitudes.

Both the barbastelle and the Bechstein’s bats are rare species of woodland bats, with only a few confirmed breeding colonies nationally so the Dartmoor discoveries add significantly to our understanding of the ecology and distribution of both species.  Up until recently, it has been very difficult to research the habits of these woodland bats but now new technology using acoustic lures that playback the bats’ calls and attract them into nets is enabling researchers to catch them in remote woods and follow them on their nightly forays.  These two bat species roost under peeling bark and in splits and holes in damaged and dead trees - just the sort of habitat one might be inclined to ‘tidy up’ in woodland.

The Dartmoor National Park Authority is hoping to follow up his work with practical conservation action to secure the bat’s future.  As a top predator, barbastelles are at the head of the food chain and depend on a well connected healthy landscape.  Thus conservation measures to benefit the barbastelle could potentially benefit a whole range of other species and habitats.

There are seventeen bat species in the UK, of which 15 have been found in the Dartmoor National Park.  Because of their declining numbers in the past, all UK bats are protected by law.