LEEDS / SHEFFIELD (UK)—A type of bat never seen before in the U.K. has been found swarming in caves in Yorkshire and Sussex.
Alcathoe’s bat (Myotis alcathoe), which is about the size of the end of a person’s thumb, was first “discovered” in Greece in 2001 and is a native of continental Europe. Until now, scientists presumed the English Channel acted as a barrier that had prevented the bats from reaching the U.K.
A research team led by John Altringham, a professor at the University of Leeds, and Roger Butlin, a professor at the University of Sheffield, identified the bats in the U.K. during a Europe-wide study of bat population ecology and genetics.
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 more than 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 U.K. but has not been spotted before because its appearance is so similar to other bat species.
“Over a third of the U.K.’s native land mammal species are bats, making them by far the biggest contributor to our mammalian diversity,” says Altringham. “This discovery takes the number of bat species established in the U.K. 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 U.K. species means it has gone unnoticed.”
Butlin says the team’s genetic analysis of mitochondrial and nuclear DNA “places Alcathoe’s bat as a very close relative to the whiskered bat (M. mystacinus) a widespread but relatively uncommon U.K. 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.”
Genetic analysis is carried out on a tiny piece of wing membrane. The tissue grows quickly, resealing the small hole, so the bats come to no harm and many have been recaptured several times over the years.
“Alcathoe’s distinctive echolocation call,” notes Altringham, “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.”
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