AGE – BEST CRITERIA:
Since the pre-br moult in most individauls is rather restricted (at most, some inner GC and TT may be included), the ageing characters used in autumn are still mostly valid. In 2cy, moult contrasts are often present in outer GC and sometimes also in AL, RR and TT. Adult birds show a generally uniform, dense and less worn plumage.
2cy:
- If present, juv GC (commonly 0-4 juv GC unmoulted) are detectable by being warmer brown, more worn and with looser texture. If all GC are moulted, there is still a contrast between retained juv PC and GC (less easily detected). Note that outermost GC1 sometimes is slightly browner than other GC (even within the same generation), and an assessment of feather structure is recommended.
- Juv PC are worn and usually show a looser texture and more brownish edges compared with ad birds.
- Juv AL are rather brownish (and in the same state of wear as PC), sometimes contrasting with post-juv AL showing fresher greyish or olive edges and glossy dark/black centres.
- Juv TT show a looser texture and a browner ground colour and contrasts with post-juv GC. Note that some birds may show TT moulted in either the post-juv or pre-br moult.
- Juv RR (as well as PP) are generally narrower, slightly more pointed and more worn compared to ad ones.
3cy+:
- Whole plumage is in better condition. A few birds may show pre-br inner GC or TT, but most birds at Ottenby lack visible moult contrasts in the wing.
- PC are dense and often show greyish or olive edges.
- AL show glossy dark centres with greyish or olive edges.
- TT show a dense texture and a more olive ground colour, similar to the GC.
- RR (as well as PP) are broader, and in better condition.