Cyanistes caeruleus - Autumn - Ringers Digiguide

AGE – BEST CRITERIA:

Moult contrast is always present in the wing of 1cy, in the vast majority between post-juvenile GC and juvenile PC. Moult contrast may also be present in RR, alula and TT. Adult birds show a uniform and freshly moulted plumage.

1cy:

Most birds include all GC in the post-juvenile moult. The fresh and dense GC with rather bright blue outer vanes shows a contrast to the less dense and less brightly coloured juvenile PC. This contrast may be easily detected, but a few may need a more careful study. In some birds (14% at Ottenby) 1-5 outermost GC may be unmoulted juvenile (less dense and less bright blue), and then show a more easily seen contrast to inner post-juvenile GC.
A moult contrast is sometimes seen in the alula, often with CC and the innermost alula moulted post-juvenile contrasting to outer 1-2 juvenile alula. Post-juvenile alula are more dense and bright blue (like the post-juvenile GC) than juveniles ones.
Most birds, c. 70% according to Jenni & Winkler (1994), moult all TT. Among the rest, the vast majority shows one (the longest) unmoulted juvenile T, while 2-3 retained juvenile TT are rather rare.
C. 70% (according to Jenni & Winkler [1994]) moult R1, and 5% include several RR. Only c. 25% moult no RR at all.
Iris is rather dark olive-grey.

2cy+:

Uniform plumage lacking any moult contrast.
PC denser and with a slightly brighter blue gloss.
Iris usually slightly warmer greyish-brown.

1cy October. One of rather few individuals showing a moult contrast in GC: Outermost GC1-2 are juvenile (as are the PC) in contrast to inner post-juvenile GC3-10 showing brighter blue outer vane and a more dense structure. [1ET80970]

1cy October. Another bird showing moult contrast in the GC, here with GC1 unmoulted juvenile in contrast to post-juvenile inner GC2-10. [1ET81028]

2cy+ November. Whole wing post-breeding, with no contrast present. [1ET81045]

2cy+ October, showing variation. [CM10453]

1cy September. Note the juvenile PC, less dense and slightly less brightly coloured than post-juvenile GC, CC and AL. This individual has moulted all GC (and the contrast is therefore found between the GC and PC) which a very common strategy in the species). [1ES24845]

1cy September. Another one with typically uniform post-juvenile GC in contrast to juvenile PC. [1ET80486]

2cy+ November. Adult PC are denser and generally shows a slightly brighter blue gloss. Note the lack of contrast to GC, both in colour and structure. [1ET81045]

2cy+ November, showing variation in post-breeding PC. [1ET81026]

1cy October. Most 1cy, like this one, include both R1 in the post-juvenile moult, but a few are more (or less) advanced. Note the contrast between post-juvenile R1 (more fresh, dense, blunt-tipped and slightly brighter blue) and the remaining juvenile RR. [1ET80982]

1cy October, showing a full set of juvenile RR, separable from the post-breeding RR of adult by a pointed shape to the tips as well as more pronounced wear. [1ET19347]

2cy+ November. A uniform post-breeding tail. Note the fresch and blunt-tipped feathers. [1ET81026]

2cy+ October, showing variation. [CM10453]

1cy October. Most 1cy, like this one, include all TT in the post-juvenile moult. But a portion of the young birds shows a moult contrast, often with the longest T being unmoulted juvenile. [1ES24410]

1cy September. One of rather few birds showing a uniform set of juvenile TT. [1ET80486]

Cyanistes caeruleus - autumn