Nigel - Always interesting to hear about Hobby breeding season, and nice to know others are out there watching. Sorry to hear breeding success was low though.
I've been fortunate enough to free up some time this summer and re-visit some old haunts. There has breeding success at four sites, two young raised at two sites, and at least one young raised at each of the other sites. Time limitations at these two sites mean I couldn't confirm any other young there, although I suspect at least another juv at one of the sites.
Interestingly a 2nd cy bird was present at one site, unfortunately I got there too late to ascertain if this was the breeding female. However this remains a possibility and could account for low breeding success, i.e. raising just one young?
However no site produced 3 young as I have previously seen.
Unfortunately not enough time to check out 3 potential other sites, roll on next Spring.
John - glad you're seeing good numbers in the east. I'm sure your right about distribution of breeding pairs in generally under watched sites, I rarely see a soul at any of these breeding locations, and certainly not any other bird watchers!
There are certainly more sites out there, having witnessed some clashes between the resident pair and presumably another local pair at one site in particular. This culminated in a spectacular display when one of the dualling pair locked talons, disengaged, locked talons again and then spiralled to the ground. I lost them below a tree line, but presumably they disengaged before hitting the ground as I managed to pick up the chase again a few seconds later.