Outside our kitchen window is what we had always assumed was an abandoned nest-box. Recently, though, we noticed several things: (i) our two cats were taking an inordinate interest in it, (ii) adult birds were flying missions to and from the box and (iii) an extraordinarily courageous wagtail was distracting the cats by hopping about on the lawn and generally tormenting them by flying overhead.
Naturally we fretted about the fate of the birds, and for two days kept the cats indoors, much to their chagrin. Then this morning my wife saw this little chap on the roof of our study. He had just flown for the first time and had alighted to savour his new freedom (and perhaps also to recover from the shock). He looked at her impassively as she took his portrait.