We start with one bird, presumably Angus, inside Box3.
Both Abby and Angus have been seen around Box3 quite often today. ( For those who have not read yesterday's post, we are calling the bluetits occupying Box3 Abby and Angus in memory of the 8 chicks that that pair lost last year. We do not expect that they are the same birds. Possible, yes - but unlikely.)