AGE – BEST CRITERIA:
In 1cy, moult contrast is present in GC, most often in the inner part of the arm. Adult birds show a uniform and freshly moulted plumage (often with exception for unmoulted worn S6).
- Moulted GC (often the 1-3 innermost) are slightly more dense, slightly darker (glossy) centre and with neater olive fringes than the unmoulted juvenile ones. The latter ones are less dense, slightly more worn, a trifle paler and usually show a rather characteristic pattern with wide wedge shaped pale tip. In birds where no GC was moulted, the juvenile GC contrast to any moulted post-juvenile MC.
- The juvenile TT (most easily assessed in the central feather) shows whitish tips that are wider on the outer vane, creating a ‘step’ to the more narrow white on the inner vane.
- Juvenile RR are generally slightly more narrow, more pointed and less dense than adult ones, but differences in shape are not always obvious. Note that difference in dark ground colour of the RR is partly explained by sex.
- The juvenile PC usually shows slightly looser texture and are often paler brownish grey, but differences are not always obvious.
- Whole plumage fresh, lacking moult contrasts. Note, however that some birds have suspended their complete moult and may show unmoulted worn S6.
- Adult post-breeding GC and TT have a slightly darker centre and more narrow pale tips that rounds the feather without widening to a ‘step’ or to a triangular shape.
- Adult RR are generally more dense, slightly wider and more blunt tipped. Note that difference in colour of the RR is partly explained by sex.
- Adult PC are generally more fresh, denser and often darker grey.
NOTE: We have no photos of 2cy+ autumn birds to show (adults are very rare in our trapping during autumn). Still, we choose to show some 1cy birds, and we recommend comparing these to adult autumn hypoleuca since ageing is based on similar characters.