Derek,
I saw a similar thing last year whilst visiting a bird sanctuary in Sussex last year. there was a small pond surrounded by overhanging trees and swooping down back and forth was what I first thought was a swift. It was mid-afternoon and hot. I soon realised that it was a bat and thought this very unusual. when I got back to the visitor centre I mentioned this to one of rhe volounteers and the got the &big book of bats' and identified it as a Duabenton (?). It looked like it was either drinking or taking flies off the surface.
Excellent photos, those things can really move...!
Ewan
