Yes several flavours of bat were detected near cave entrances. Here's an extract from GSG Newsletter 150 page 4, March 2012:-
A project monitoring some of the Assynt cave entrances by the North Highland Bat Network has found evidence of three species in the area: common pipistrelle (Pipistrellus pipistrellus), soprano pipistrelle (P. pygmaeus) and Daubenton?s bat (Myotis daubentoni). Most of the monitoring was by unattended bat loggers left in place for about a week during August and September 2009, 10 & 11. Many of the thirteen sites that were monitored recorded no activity, but some ? Bone Caves, Rana Hole, Uamh Cailliche Peireag - ?probably? recorded some activity. Interpretation is said to be difficult as the recorders can be triggered by high winds and rushing water as well as bats. Another type of detector that records the sound and can identify the species was used at the Bone Caves, Tree Hole and Uamh an Tartair (Knockan), the last for two weeks. Bats were detected at all three with the most passes (168) at Tree Hole. This is considered to be foraging activity along the stream channel. In addition members of the project team with hand-held bat detectors did three 45 minute emergence counts at the Bone Caves and recorded a bat during two of them.
The NHBN report concludes ?that it is likely that Assynt Caves are used by low numbers of bats, giving particular caves (i.e. Bone Caves (4), Cnoc Nan Uamh (upper) [ie Uamh Cailliche Peireag] and Uamh An Tartair (Knockan)) a Grade 2 status of importance as underground sites for bats. Further bat survey work could be undertaken at Rana Hole when full access is possible for bats.? It also expresses concern at our proposed gate at Rana Hole if it completely blocked airflow and hence bat access.
The evidence for bat use is scanty with only two confirmed sightings during the emergence counts at the Bone Caves. All other detections could represent foraging activity and not cave use. While there have never been any reports of bats being seen in Assynt caves, that doesn?t mean they don?t use them. What is needed is more data and the GSG will be volunteering to help the Bat Group place detectors inside the caves and supply them with more information about the conditions underground.
I have not heard of any other work being done since 2012 and we've not had any reports of bats in any of the caves. We do see them swooping past the hut windows regularly during summer evenings.
