AGE – BEST CRITERIA:

Pattern and moult status of GC is generally easy to assess. In 1cy, a moult contrast is present among inner GC. Ad birds show a uniform and freshly moulted plumage.

1cy:

• Most birds (at Ottenby 97%) include 1-3 inner GC in the post-juvenile moult. Juvenile GC show a looser structure and a pale rusty wedge-shaped spot at the feather tip. Difference in wear between juv and post-juv GC in early autumn is not always obvious, but post-juv inner GC are denser, show darker grey centres and usually lack the pale tip (instead show neat olive-brown edges).
• Juv PC are often slightly less dense and more loose/frayed than in ad, but this difference is often difficult to detect. In many young birds the pale wedge-shaped GC-tips continue out onto the inner PC.
• Juv TT usually mirror the pattern and structure of the juv GC, and are often slightly narrower and more pointed than ad type feathers.
• Juv RR are on average slightly more pointed, paler and (as autumn progresses) worn, but this feature is often rather difficult to use for ageing.

2cy+:

• Whole plumage fresh, lacking moult contrasts.
• GC are uniformly olive-brown with no (or only weak) pale tips.
• PC are slightly more dense, fresh, often with neat grey to warm buff edges (but lacking pale wedge-shaped tips).
• TT are dense in structure and show evenly pale edges, similar to the post-br GC.
• RR are on average slightly blunter, darker and in better condition.