AGE – BEST CRITERIA:
Autumn criterias are still applicable, though 2cy are more affected to wear during the winter than adult. Moult contrast present in the wing of 2cy, often in the central GC (but very variable, and rarely all GC may be moulted) and sometimes also in RR and TT. Adult birds show a uniform plumage in relatively good condition.
- Nearly always show moult contrast in the GC, commonly in the central or outer part of the arm: Less worn post-juvenile inner GC are denser, longer, show a darker (blackish) centre and wider and more yellow tips than the more worn juvenile outer GC that often show loose, more narrow and pale yellowish-buff tips and a paler grey centre. A few show less extensive moult and the contrast may then be hidden under the scapulars. Rarely, all GC may be moulted, and the contrast is then found towards the still juvenile PC.
- Juvenile RR are on average more pointed and worn than adult ones, but wear sometimes makes this less easy to judge. Many individuals have moulted single or several RR and then exhibit moult contrast among RR. According to Jenni & Winkler (1994) a few individuals may have included the whole tail in the post-juvenile moult, but reasonably more common in southern populations.
- 0-3 TT were included in the post-juvenile moult. Post-juvenile TT are less worn and show a darker (blackish) centre and often more colourful yellow and white edges/tips than the more worn and slightly paler grey juvenile ones, with more narrow and yellowish-white edges.
- Juvenile PC are generally more worn, less dense and slightly more brownish-grey than adult ones.
- Uniform plumage lacking any moult contrast.
- Whole wing and tail in better condition with denser feathers and better gloss.
- Tips of RR generally slightly more blunt and broader.