The largest landscape scale UK study into rare bats, including the rare greater horseshoe bat, was launched in Purbeck, Dorset in September 2007.

Conducted by a Bristol University researcher, the Purbeck Bat Project will, over the next three years, research the roosts, flight patterns, diets, habitats and the influence of farming practices on the greater horseshoe bat and other bats in the Purbeck area.

A unique partnership

In a unique partnership, many of the landowners on Purbeck, including the National Trust, Dorset County Council, Dorset Wildlife Trust, the MOD, the RSPB, and other conservation bodies such as English Nature and the Dorset Bat Group have joined together.

The aim is to try to find out how bats use the landscape within the Purbeck area so that measures can be put in place to safeguard roosts, flight lines and feeding areas.

Financial support from SITA Trust, through the Landfill Tax Credit Scheme, and partners of the project are funding a three year PhD student from the University of Bristol. He will be tagging the bats and using radio receivers to record their flight patterns, which can range as far as 30 miles in one night, to locate their night roosts and feeding areas.

The UK population of greater horseshoe bats has been estimated by one survey at 4000 individuals. Only 200 breeding females are believed to be in Dorset, which is the eastern edge of its range in the UK.

However, it is a time of range expansion and the greater horseshoe bat offers a model of how an animal on the edge of its range can move once it has been given room.

Several partners including the National Trust and Dorset Wildlife Trust have recently restored some of the disused quarries on Purbeck, at Acton. Part of the study will focus on the bats’ use of these abandoned quarries.

Greater horseshoe bat facts

• Greater horseshoe bats are classified as rare and endangered.

• They can live to be 30 years old. They do not start breeding until three or four.

• They gather to breed in warm roof voids of old stable blocks or large houses and hibernate close to their summer roosts in cellars or underground quarries.

• The bats feed entirely on insects, especially moths and beetles.

• They navigate across large areas of countryside at night, often following hedgerows and woodland edges.

As the bats are no respecter of landowner boundaries, this project is unique in that it involves all the main landowners on Purbeck, as well as private landowners. This allows the project to study the bats across a wide area.

Local people who are interested in learning more about bats are enlisting their help to track their flights during the evenings using bat detectors.

Early findings

The project is already beginning to build up a picture of where the bats are feeding and what routes they are using. Thirty two greater horseshoe bats (14 males, 18 females) have been caught so far.

The results of the project will be invaluable in helping get a clear view on how the Trust's management of habitats and agricultural practices can be prioritised. This will ensure the continued survival of the rare bats of Purbeck.

From September 2007, the project will be monitoring the annual bat swarming, a social behaviour phenomenon/mating strategy which takes place every autumn.

One of the questions that the project will be looking to find answers for is the reason bats return to their winter roosts to swarm when they don’t use those sites as roosts during the summer and autumn.

How you can get involved

If you would like to volunteer for the Purbeck Bat Project please contact Angela Peters at the Purbeck Estate Office on 01929 450259.