So, down to business. This bird was actually quite boring. It was, not unexpectedly, in primary moult. The secondaries appeared to be of a single generation (though they might not all have been grown in one clean sweep) — the outer and especially the inner ones appeared a smidgen older but that's presumably because they were moulted earlier in the sequence and, in the case of the inner ones, their position in the wing leading to greater wear. I couldn't find any retained juvenile coverts.
The bird isn't a first-year (obviously). Even the most advanced second-year should theoretically still have some juvenile secondaries, so this bird isn't a second year. Some third-year birds can still be aged on the basis of retained juvenile secondaries; other third-years have moulted the last of their juvenile secondaries and can no longer be aged. This bird could fall into the latter category; it could of course be older but there is, on the basis of plumage, no way of knowing for sure. Thus the bird is a 3+cy (third-year or older, EURING age 6).
You've probably noticed in the first photo that the bird is a lovely deep pink (almost purple in places) on the breast and shows a thick chunk of white on the neck (almost meeting across the nape); the neck also showed a good slither of green and purple, and the upper tail coverts/rump were a nice bluish-grey.
There's quite a bit of overlap in measurements between the sexes, so having a wing of 256 mm didn't help either way. The weight — 500 g, more-or-less (weighed using the kitchen scales; shhh, don't tell my mum) — was also in the (extensive) overlap zone. However, all-in-all I think the combination of plumage traits should make it safe enough to call this bird a male.
I assumed that would be all for today, though in a fit of optimism I threw some bread out onto the lawn and onto the border beside the net. It didn't take long before an unringed Woodpigeon arrived in the garden. It scoffed the bread on the lawn then spent 15 minutes pacing up and down the length of the net trying to work out how to get to the bread on the other side. Eventually it worked out it could walk around the end of the net to reach the bread on the border. I have a walk-in trap there, cobbled together some some slithers of old chicken wire; it doesn't work, of course, but I live in constant hope that a Woodpigeon will one day wander in. This bird got as far as sticking its head in to reach the bread inside. I decided that if I ran into the garden, the bird might leap forward and into the trap. It didn't; but it did leap sideways and into the bottom shelf of the net. With a dive to the ground that would have made any professional footballer proud, I grabbed the bird. Woodpigeon number two!
On the face of it, this bird is slightly more interesting; it shows two generations of secondaries (two old but still seemingly adult-type, arrowed). It is also in primary moult, one primary 'ahead' of the first bird.
However, when we work things out we come to the same conclusion: that this individual is a 3+cy. We want to work out minimum age so we need to work on the basis of maximum extent of moult. Let's imagine this bird, during its 1cy, moulted S1–2 and S11–6. Then during its 2cy it recommenced secondary moult from the same position and moulted S3–5; at the same time, it started another wave of secondary moult from both the outside and the inside, moulting S1 and S11-7 in the process. Thus, S2 and S6 are left as old secondaries. The bird's minimum age is therefore 3cy (but it could, as before, also be older) — thus it's aged as a 3+cy (EURING 6).
Compared to the first bird, this individual did not show e.g. such extensive white on the neck nor such a deep pink colour to the (in particular, lower) breast.
NB the bird has lost most of its upper tail coverts, thus the base of the tail is exposed.
A wing length of 145 mm was in (the lower end of) the overlap zone. This individual was slightly heavier than the first at ~520 g... though bear in mind it has just necked half a loaf. Although the bird didn't look so male-like as the first, it didn't look terribly convincing for an obvious female either and it's my opinion that this bird is best left unsexed.
There's a pair of Dunnocks nesting in the garden and I managed to catch both parent birds; both 3+cy. My sister was quite disgusted when I showed her the male's cloacal protuberance...
Also three Long-tailed Tits and a Goldfinch ringed.