Sorry to disappoint so soon but I plan on saying absolutely nothing about the race of this bird.
It's something of a bugbear of mine that birders inevitably refer to bright male Passerines as 'adults'; a first-winter, it seems, needs to be dull. That does hold true for some species and it can be a suggesting feature for others — indeed I mentioned this fact when I was discussing last week's Wheatear. It is also true that many first-winter individuals in many species are duller than adult birds but this is not always the case. As first glance, you'd be forgiven for thinking this Yellow Wagtail was an adult. Indeed, I suspect if I'd seen this bird at distance in the field I'd think the same.
I'll make my excuses for the awful photos early. Photographing anything at Flommen is a nightmare; it's open and windswept. Anyone who's ever tried to photograph a bird in windy conditions will know that 'with a bit of wind under their wings' they tend to flap. The only sheltered area when the wind is blowing from the sea is right in front of the bright white ringing hut... but that's in full sun and gives the photos a horrid white wood-panel background, so windy with sandy background is the lesser of two evils. Hence the ugly 'anti-flap' grip.
Anyway, a look at the wing reveals that the bird is in fact a 1cy. It shows an obvious moult limit in the greater coverts (seven unmoulted juvenile feathers), in the median coverts (innermost and outermost [under my thumb] unmoulted) and in the lowest row of lesser coverts (two feathers unmoulted).
There is also a moult limit in the tertials. Most obviously, the middle tertial has been moulted on the right wing but not the left.
In addition to the rather advanced-looking body plumage, the bird showed an iris that was more in-line with what one would expect from an older 3+cy bird than a 1cy bird. 1cy birds show a dull almost grey iris; this bird's iris was a rich brown almost reddish-brown.
I appreciate that a bad photo of an iris like that means very little in isolation; I'll try and photograph a more typical 1cy under the same conditions over the course of this week if I can.
All-in-all, the bird showed a rather extensive post-juvenile moult; brighter than expected post-juvenile plumage; and a more mature-looking than expected iris. It's my suspicion that all of these are related and are due, at least in the most part, to high hormone levels. This individual goes to serve as something of a warning that it's probably not a good idea to age a bird based solely on 'brightness' and overall appearance, nor based solely iris colour — and that the same individual may be prone to show extremes in both of the features.
Another interesting bird was this 2cy Common Whitethroat. It was in active wing moult but still showed three generations of secondaries.
S1 is new post-breeding, S2–3 are old juvenile feathers, and S4-6 are pre-breeding feathers grown this spring. P9 is also old (juvenile or perhaps pre-breeding). I wonder if it will arrest its secondary moult like Friday's individual had done? Today's bird also shows some old and very worn outer median coverts.
I cycled up to the harbour road pools this afternoon. There were plenty of ducks — including three Garganey — but not too many waders; three Wood Sandpipers, a Spotted Redshank, and some Greenshank, all juveniles.