The largest hibernation of pipistrelle bats in the UK has been recorded at Seaton Delaval Hall in Northumberland.
Sixty-one pipistrelle bats were found in stone crevices and in the arches of a balcony at the hall earlier this year, revealing previously unknown information about the bats’ hibernation habits.
Ecologists had believed that the pipistrelle prefers to hibernate in very dark, damp conditions. However, these bats were found hanging out in a dry, arid, relatively well-lit area of the grand 18th Century building.
Tina Wiffen, bat ecologist said: “We discovered the bats when we were undertaking an ecological survey to assess the possibility of introducing new art and visitor information installations into the Central Hall of the building – a project being supported by the National Lottery.
“On finding the bats, we conducted a formal survey and at least 60 bats were counted in February and 61 in early March – with more visits then needed for verification. It’s likely that even more bats are here, hidden in deeper crevices. “As a result the site will now be even more closely managed and monitored to ensure that the bats can continue to use the hall as their winter roost.”
Bats first came to roost at Seaton Delaval Hall after it was ravaged by fire in 1822. The building was left exposed to the elements for around 40 years before being reroofed in the latter half the century, making the space warmer and drier, but with the bats still able to gain access through the crevices in the stonework.
David Bullock, Head of Nature Conservation at the National Trust visited the Hall recently to verify the findings. He said: “I’ve never encountered hibernating pipistrelles in such numbers before. The cavities in the stones in Seaton Delaval Hall’s Central Hall provide one of the few known hibernation sites of what could be hundreds of bats. “
Before any further repairs and conservation work begin at Seaton Delaval The National Trust plan to further survey the spaces. This will help them to understand more about how the bats interact with in the Great Hall so it can protect and look after the pipistrelles.