By Judith Burns
Science and environment reporter, BBC News
In the UK Bechstein's bats are confined to a few counties in southern England
One of Europe's rarest bats has been found at a site in Wales further west than ever before recorded.
The Bechstein's bat is an elusive creature that likes to hide in the undergrowth of ancient woodland.
It lives in a number of countries in western, central and southern Europe, but is rare throughout its range.
Now a researcher from the University of Bristol has identified a solitary male specimen in Pembrokeshire, 100km west of earlier recorded sites.
University of Bristol researcher Matt Zeale found the bat while pursuing another species in woodland owned by The National Trust at Colby in southern Pembrokeshire.
He told BBC News he couldn't believe his eyes when he found it in his trap: "I was really shocked though it was a nice surprise as well.
"Bechstein's have these quite long ears and a few other features you can use to tell them apart from the other species we have in the UK. So it was the first thing I thought of.
"Because they have never been recorded anywhere remotely near here, I had to double take and triple take and re-measure and re-measure just to make sure."
Ultrasonic bat lure
Mr Zeale was using an ultrasonic bat lure to attract a slightly less rare species, the Barbastelle, as part of his PhD research. The device makes bat calls for specific species so he was doubly surprised to find that he had caught a Bechstein's bat.
Bechstein's bats feed on spiders and insects that rest on plants
Having made his measurements, Mr Zeale let the bat go. He says what it was doing in this location is a mystery. Not only is it a long way from other recorded Bechstein sites, but the area is generally considered too wet for the species, which generally prefers dry conditions.
David Bullock, the National Trust's head of nature conservation said: "We can only speculate where this male Bechstein's bat might have come from. He either made an incredible journey from the Forest of Dean or Herefordshire or more likely there are other roosting sites waiting to be discovered in Pembrokeshire."