Greater horseshoe bats
Gareth Jones
Press release issued:
31 October 2007
Genetic work carried out as part of a Bristol University research project on the National Trust Purbeck Estate in Dorset has found that the UK’s population of greater horseshoe bats originated from west Asia around 40,000 – 60,000 years ago.
Genetic work carried out as part of a Bristol University research project on the National Trust
Purbeck Estate in Dorset has found that the UK’s population of greater horseshoe bats originated from west Asia around 40,000 – 60,000 years ago.
By taking tiny, harmless tissue samples the project found that greater horseshoe bats colonised Europe before the last ice age. Samples were taken from sites across the species natural range from the UK to Japan, including Purbeck. DNA was extracted, sequenced and compared between different populations.
In 2005 the National Trust and the University of Bristol launched the UK’s first landscape scale study into bats. During the course of his PhD, researcher Jon Flanders looked at roosts, flight patterns, diets, habitats and the influence of farming practices on bats in the Purbeck area, as well as the genetics of the greater horseshoe.
Jon Flanders, commenting about the findings, said: “It is amazing how we can look back at the history of the greater horseshoe bat and see how its distribution in Europe has altered over the last 60,000 years. This is not only important information in understanding the natural history of this bat, but could also reflect similar movements of other species of animal found in Europe.”
The research was carried out in collaboration with another genetic project by Stephen Rossiter at Queen Mary, University of London. His research found that when the last ice age advanced, the greater horseshoe was forced to migrate to southern Europe along with bears, hedgehogs and grasshoppers. As the ice retreated, the bat returned to Northern Europe and the UK.
David Bullock, Head of Nature Conservation at the National Trust and bat expert, is enthusiastic about the findings, added: “We know the National Trust is extremely important for bats, but there are still so many mysteries surrounding their behaviour and ecology. Every new piece of information can help to shape our management plans and protect these rare creatures in the future.”
Working in partnership, the research project brought together the National Trust, Dorset County Council, Dorset Wildlife Trust, MOD, RSPB, Forest Enterprise and other conservation bodies such as Natural England and the Dorset Bat Group. Private landowners were also involved as bats use the whole landscape.
Further information
The National Trust and bats
In 2005 the National Trust published 'Nature and the National Trust' which established priorities for the nature conservation work of the organisation. One of the key species identified was bats and the work necessary to protect them.
The National Trust is particularly important for bats. All 17 species in the UK are found on Trust land. Historic buildings and ancient woodland provide important roost and hibernation sites. Farmland, parks and water are vital for feeding. Even air raid shelters, grottos and icehouses have become homes to bats.
Further findings of the research
Research from the bat study has uncovered many previously unknown facts about bats and new records for the area. For example, previous monitoring of the greater horseshoe had focused on maternity roosts and little was known about the intermediary roosts. One such roost on National Trust land was thought to have just seven or eight bats, but the research showed there are over 30 individuals, a much more significant number.
Two new populations of Bechstein’s bats and three maternity roost trees were found. A female Barbastelle was also found indicating that there is at least one maternity colony at Purbeck. These findings will help build a more detailed population picture of these species in the UK.
A network of disused quarries has been discovered to be nationally important for swarming bats, a behaviour that we still know little about. Dozens of bats descend on the area in the autumn and swarm around the quarries. By catching the bats, it was found that most were male and this suggests it is a pre-mating gathering for displaying to females. The research found that different species use different quarries for swarming.
Greater horseshoe facts
Once widespread, the greater horseshoe population has declined significantly across northern Europe and the UK during the last century. Changes to the way we farm our countryside are partly to blame. As agriculture intensified, the insects that the bats depend on disappeared from feeding grounds. On top of this, hibernation sites have declined by 23 per cent. Now that we are returning to more environmentally friendly farming, these traditional feeding grounds are being restocked with beetles and moths, favourite foods of the greater horseshoe.
The UK population of greater horseshoe bats has been estimated by one survey at 4000 individuals with only 200 breeding females believed to be in Dorset.
Greater horseshoe bats can live to be 30 years old and 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.
They navigate across large areas of countryside at night, often following hedgerows and woodland edges.
Project support
Financial support from SITA Trust, through the Landfill Tax Credit Scheme, partners of the project, Mammals Trust UK and BP funded the three year PhD student from the University of Bristol.
