We found two broods of Tawny Owls, which was two more than last year. Perhaps not as many as I would have liked, but we can't be too fussy. One brood was just big enough to ring, the other slightly too small. We managed to catch and ring the adult females in both boxes as well - interestingly, both older birds and both unringed.
The wing of one of the adult female Tawny Owls, showing three generations of primaries.
However, perhaps the most encouraging thing about today's broods was the amount of prey cached in each box. The first contained 5 voles and the second at least 12 items, seemingly a mixture of mice and voles (see below).
Of all the other boxes that we checked 5 were empty, 2 damaged, 3 had Jackdaw clutches and 2 had Stock Doves. So all in all, a reasonable start to the season, though it would be nice if the Barn Owls could do a little better.