As of this morning we still only have the three swifts in residence. Box 3 pair are spending a lot of time in the box, (but have just gone out as I write!) and box 1 single comes and goes, but all three are roosting at night. It is obvious that whatever partner that box 1 had went missing so we're very much hoping that it will bring in a new partner very shortly.
All gone out for the day!