, or Alcathoe's bat, was identified by a research team led by Professor John Altringham at the University of Leeds and Professor Roger Butlin of the University of Sheffield during a Europe-wide study of bat population ecology and genetics.
Alcathoe's bat - which is about the size of the end of a person's thumb - was 'discovered' in Greece in 2001 and is a native of continental Europe. But until now, it was presumed that the English Channel acted as a barrier which had prevented it reaching the UK.
In Yorkshire the bats were found in a Forestry Commission woodland in Ryedale in the North York Moors National Park, a biologically rich site that was home to the north of England's last known colonies of rare barbastelle and lesser horseshoe bats over 50 years ago.
The southern sites are in the South Downs of Sussex, a wooded area known for a number of rare woodland bat species. Alcathoe's bat may well be present in many other parts of the country.
The researchers believe the bat is actually resident in the UK but has not been spotted before because its appearance is so similar to other bat species.
Professor Altringham said: "Over a third of the UK's native land mammal species are bats, making them by far the biggest contributor to our mammalian diversity. This discovery takes the number of bat species established in the UK from 16 to 17. Most of the bats were captured as they entered underground "swarming" sites, where bats gather to mate before going into hibernation. A single swarming site, usually a cave or disused mine, can attract thousands of bats of ten or more species. This makes them good places to look for rare species.
"Its presence at sites 350 km apart suggests that Alcathoe's bat is a well-established, resident species. Preliminary evidence suggests that it makes up a significant proportion of the small Myotis bats at both the Yorkshire and Sussex sites. Its close resemblance to two other UK species means it has gone unnoticed."
Professor Butlin said: " Our genetic analysis* (mitochondrial and nuclear DNA) places Alcathoe's bat as a very close relative to the whiskered bat (M. mystacinus) a widespread but relatively uncommon UK species. These two species and a third, Brandt's bat (M. brandtii), are so similar in appearance that identification based on appearance alone can be difficult even for the unwary expert."
Prof Altringham added: "However, Alcathoe's distinctive echolocation call, which terminates at a significantly higher frequency than those of its relatives (43-46 kHz), alongside some subtle physical differences makes identification possible without genetic analysis.
"Although similar in appearance these three bats may prove to be ecologically quite different. The separation of the common pipistrelle into two species in the 1990s led to the discovery that despite their physical similarity they have significantly different roosting habits, feeding habitat and food."
Brian Walker, Forestry Commission Wildlife Officer for the North York Moors, said: "We have some incredibly rich bat habitats in North Yorkshire and it was only a few years ago that work locally helped to confirm that the common pipistrelle was actually made up of two different species. The discovery of Alcathoe's bat is another first to add to the record books."
Photo credits: Cyril Schönbächler
Graham Askew, Simon Walker, BBSRC (Jan 2018), £699,781
Jennifer Tomlinson, Royal Society (Jan 2018), £512,801
Adrian Whitehouse and colleagues in School of Chemistry and University of Liverpool, MRC (Nov 2017), £622,319
Michelle Peckham, Neil Ransom, MRC (Nov 2017), £495,159
Dave Lewis, British Council India (Nov 2017), £22,540
Elton Zeqiraj, Royal Society (Nov 2017), £15,000
Hannah Dugdale, Royal Society (Nov 2017), £15,000
Shaunna Burke, Cancer Research UK Innovation Grant (Nov 2017), £20,000
Alex O'Neill and colleagues in Chemistry, BBSRC (Nov 2017), £431,865
Jessica Kwok, Wings for Life (Nov 2017), £87,365
Tom Bennett, BBSRC (Oct 2017), £523,679
Neil Ranson, Darren Tomlinson, BBSRC (Oct 2017), £494,318
Nikita Gamper, BBSRC (Oct 2017), £490,426
Amanda Bretman and colleagues from UEA, NERC (Oct 2017), £430,886
Juan Fontana, Rosetrees Trust consumables grant (Oct 2017), £22,500
Helen Miller, DSM Nutritional Products AG (Sep 2017), £69,988
Neil Ranson, Juan Fontana, Mark Harris, Michelle Peckham, Ralf Richter, Peter Stockley, Patricija Van Oosten-Hawle and colleagues in Engineering, FMH and MAPS, Wellcome Trust Equipment Call (Sep 2017), £418,000
Jamie Johnston, Physiological Society (Sep 2017), £10,000
Frank Sobott, Adrian Goldman, Mark Harris, Andrew Macdonald, Stephen Muench, Sheena Radford and colleagues in FMH and MAPS, Wellcome Trust Equipment Call (Aug 2017), £415,000
Ralf Richter, David Brockwell, Eric Hewitt, Jessica Kwok, Emanuele Paci and MAPS/FMH, BBSRC (Jun 2017), £600,000
Eric Blair, Adrian Whitehouse, Nicola Stonehouse, Alison Baker, Richard Bayliss, Joan Boyes, Ryan Seipke, Sally Boxall and MAPS/FMH, BBSRC (Jun 2017), £376,000
Stefan Kepinski, Yoselin Benitez-Alfonso, Tom Bennett, Michelle Peckham, BBSRC (Jun 2017), £331,000
Roman Tuma, Lars Jeuken, Paul Millner, Sheena Radford, Peter Stockley and MAPS/FMH, BBSRC (Jun 2017), £222,000
Vas Ponnambalam, Darren Tomlinson, Stephen Wheatcroft, BHF (May 2017), £107,878
Graham Askew in collaboration with Bangor University, BBSRC (Mar 2017), £477,383
Stephen Muench, BBSRC (Mar 2017), £132,945
Nic Stonehouse, MRC (Mar 2017), £906,341
Bill Kunin, Steve Sait, BBSRC (Mar 2017), £602,831
Adrian Goldman, EU (Mar 2017), £546,576
Sheena Radford, Wellcome Trust (Mar 2017), £1,836,482
Jamie Johnston, Royal Society (Mar 2017), £15,000
Tom Bennett, Royal Society (Mar 2017), £15,000
Beatrice Filippi, Royal Society (Mar 2017), £15,000
Ryan Seipke, BBSRC (Feb 2017), £52,116
Mary O'Connell, BBSRC (Feb 2017), £46,986
Hannah Dugdale, NERC (Feb 2017), £504,138
Anastasia Zhuravleva, EPSRC (Jan 2017), £100,792
Richard Bayliss, Cancer Research UK (Jan 2017), £1,600,000
John Barr, EU (Jan 2017), £339,000
Mark Harris, Royal Society (Jan 2017), £250,000
Alison Dunn, NERC (Jan 2017), £105,000
Alex Breeze, Pancreatic Cancer Research Fund (Jan 2017), £180,000
Alison Dunn, NERC (Dec 2016), £18,000
Lisa Collins, BBSRC (Dec 2016), £1,681,835
Brendan Davies, Leverhulme Trust (Dec 2016), £247,555
Alan Benson, Mark Drinkhill, Ed White, British Heart Foundaion (Dec 2016), £217,223
Adrian Goldman, Royal Society (Dec 2016), £82,999
Lisa Roberts, Alex Breeze, Brendan Davies, Timothy Devinney, Oliver Harlen, Joseph Holden, Anthea Hucklesby, Pamela Jones, Philip Mellor, RCUK (Nov 2016), £484,172
Lisa Roberts, Alex Breeze, Brendan Davies, Timothy Devinney, Oliver Harlen, Joseph Holden, Anthea Hucklesby, Pamela Jones, Philip Mellor, Wellcome Trust (Nov 2016), £119,343
Katie Field, Rank Prize Funds (Nov 2016), £20,000