I am no where near educated enough to sufficiently answer your question however, I can help a little. There is a machine which is reasonably hard to get your hands which records bat sounds. It can be bought online or given to you by a local scientist who specializes in bats. However if you can’t get the machine try this. If you do have the ability to actually find where the bats roost try your best to get pictures of the bats face. Try your best not to disturb the bats but, you NEED the bats face for a confident ID to species. If your are to scared or don’t want to risk scaring the bats just get pictures of the bats body and coloration. Though you most likely won’t be able to get the observation to species it will get far enough. However, the first option is the best though.
- Jonny