My male Swift took off yesterday 26th on its return journey leaving the female bird returning to the box on her own last night easily recognisable (if you look closely) by the partially regrown wing feathers after moult; although I noticed today they are now nearly complete. For those that are interested they raised two young after 20 days incubation the young fledged after 42 days in the nest box on the 12th & 13th August the first youngster fledged in the dark ! and they were both flying around the house on the 14th with the parent birds.
Tony Clark
Bow Street