This fly was too busy concentrating on it's lunch to notice me sneaking up. It was approx 1cm long.
No interactions present.
I agree with Empis, but don't know enough to agree with tessellata.
My Flickr photos...
Is it feeding on a St Mark's Fly, do you think?
University of Edinburgh and Biodiversity Observatory (OU)
It may well have been eating a St Mark's fly as there were a lot of them around.
Lat/Lng: 51.9, -0.7
OS grid ref: SP9329