AGE – BEST CRITERIA:
Autumn criterias are still applicable, though 2cy are more affected to wear during the winter than adult. In 2cy, moult contrast is present in GC, most often in the central part of the arm. Adult birds show a uniform plumage lacking moult contrasts.
- Most birds included 3-6 inner GC in the post-juvenile moult. Juvenile outer GC show a slightly more rusty hue on the outer vane and generally rather wide pale rusty-buff tips (but may be rather heavily worn). Inner moulted post-juvenile feathers are slightly more olive green in the outer vane. Many inividuals show no pale tips at all in the post-juvenile GC, but some do: such pale tips are generally smaller, narrower, more distinct and often have a darker rusty colour than in the juvenile GC. Difference in wear between juvenile and post-juvenile GC in autumn is not always obvious in this species, but the structure of the post-juvenile GC are generally slightly more dense.
- Juvenile RR are generally more worn, narrow and more pointed, but difficult birds are sometimes seen. The structure is often helpful, with the juvenile feathers being slightly less dense, less glossy and somewhat paler brownish.
- The inside of the upper mandible is variable, but generally slightly paler than in 3cy+ birds, especially along the edges.
- Juvenile PC are often slightly less dense and more loose/frayed than in adult, but difference is not always obvious.
- A moult contrast is sometimes seen in the CC/alula area, where CC and inner alula may be moulted post-juvenile.
- Whole plumage slightly more fresh than 2cy, lacking moult contrasts.
- GC are uniformly olive with no pale tips, or with pale tips that are smaller, narrower, more distinct and often have a darker rusty colour than in the juvenile GC.
- RR are generally slightly broader, more blunt tipped and often in better condition.
- The inside of the upper mandible is rather variable, but generally slightly darker than in 2cy birds, especially along the edges.
- PC are generally slightly more fresh, dense and slightly more olive.