Breaking: Extinct greater mouse-eared bat found in Sussex

Photo credit: Daniel Whitby

Could Britain’s loneliest bat finally have a mate?  

The greater mouse-eared bat (Myotis myotis) was finally declared extinct in the UK in 1992  following decades of decline. However, in 2002, a single male was discovered hibernating in  disused railway tunnels in Sussex, only ever found alone and so became known as ‘Britain’s  rarest mammal and the loneliest soul in Britain.’ 

During monitoring surveys in January 2023, members of Sussex Bat Group were astonished to  find a second greater mouse-eared bat hibernating in the same area.  

Since these sightings, a team of experts has been monitoring and surveying to look for any  further individuals of this species, but with no further sightings in 2024, the species was thought  to have said a final farewell to Britain. However, we have exciting news: on 18 January 2025, a  greater mouse-eared bat was again found hibernating within the South Downs National Park.  This was positively identified, examined and found to be an adult breeding female.  Conservationists have ringed this bat to be able to identify it in future monitoring and research surveys for this rare species.  

This is the first identification of a new female greater mouse-eared bat in the wild since the  1980s. A network of bat conservationists, including BatCRU, Vincent Wildlife Trust and Sussex  Bat Group, are continuing to monitor and survey the area for more individuals and roosts in the  hope of finding an established breeding population in Britain.  

These regular surveys and new findings demonstrate just how vital the suite of underground  sites are. The underground structures provide a range of perfect undisturbed hibernation conditions throughout the winter for a high number of species. This along with a mosaic of rich  habitats and important woodland connecting the underground sites make this an area of  national significant importance showing how vital it is we protect these important sites

Daniel Whitby, Bat Ecologist and Founder BatCRU explained: “Having surveyed this area  persistently since the first discovery of a greater mouse-eared in 2002, the finding of a female is  rewarding and a remarkable discovery which brings huge hope for this species. This discovery adds to the list of notable findings in the area, including the discovery of Alcathoe bats in 2010;  the discovery of a Geoffroy’s bat in 2012; and a significant growing population of breeding  greater horseshoe bats — and adds to the importance of this area for bats as a nationally  significant site for a number of species found in Britain.” 

Daniel Hargreaves, Bat Programme Manager for Vincent Wildlife Trust, said: “Finding a female  greater mouse-eared bat in Britain is fantastic news, and I feel privileged to have witnessed it  firsthand. In a sad twist of fate, the lonely male who hung around since 2002 hasn’t been seen  since 2023 — but we can only hope further individuals are discovered and that a viable  population is formed. The absence of the old male felt like the final nail in the coffin for this species in Britain, but this new discovery once again sparks hope that a mammal declared  extinct could bounce back.  

“During the last two years, we have spearheaded a project in Sussex, funded by Natural  England’s Species Recovery Team, to create and enhance roosts for some of the rarest bats in  Britain, including the greater mouse-eared bat. It's vital that we protect what we have but also  create space for what we’ve lost. By providing suitable roosts, restoring habitats and reducing  anthropogenic threats such as artificial light and noise, this species might just stand a chance of recovering.” 

Nick Gray, Sussex Bat Group, said that “It is so exciting to discover these rare animals at this  site, where eleven different species of bat have now been confirmed to hibernate. The site is  undoubtably of national significance and we are so lucky to have it here within the South Downs  National Park.” 

Contacts

Daniel Whitby – BatCRU – daniel@aewc.co.uk – 07764813002 

Daniel Hargreaves – Vincent Wildlife Trust – Daniel.Hargreaves@vwt.org.uk - 07786546800 Nick Gray – Sussex Bat Group committee member and survey coordinator - nickg@clara.co.uk