A little fella came zooming out and sat in the nearest tree giving me a good look for quite a few minutes.
So the next day, Saturday, yesterday, I went along with my camera and staked out the hole. They are FAST. Way too fast when you have been hanging on to the camera for 30 minutes waiting for them to either come out or go in. At one point, the female sat on a branch about a metre from me and gave me a second appraisal.
Magic! f14 and be there.