Motacilla alba - spring

White Wagtail / Sädesärla

AGE - BEST CRITERIA:

Individual differences in wear and moult makes ageing problematic at times. Moult contrasts are often present in LC, MC, GC, tail and tertials in both age classes, and should be examined carefully.

2cy:
  • Unmoulted juvenile GC are worn, brownish with distinct and very narrow white (or buffish-white) edges and tips. These feathers contrast to either fresh pre-breeding GC (having a dark blackish-grey centre with more diffuse and broader grey to greyish-white edges and tips) or to intermediately worn post-juvenile GC (which have the same basic pattern as the pre-breeding GC, but has bleached to medium grey and have worn off some of the white in the edges/tips). Birds with all three generations of GC present are regularly seen. In birds that included all ten GC in the post-juvenile moult, the PC need to be established as juvenile (see below). 
  • Juvenile PC are usually faded pale brown and worn, but well kept birds are not always easy to separate from adult.
  • Many 2cy have tips of PP worn and faded brown (but some are more well kept).
  • Moult contrasts are often present in tertials. However, this is most often created by pre-breeding feathers contrasting to post-breeding/post-juvenile (which can not be separated) and these generations can not be used for ageing. The only generation useful for ageing is the juvenile (proving the birds as 2cy), but birds still retaining juvenile tertials (faded brown and very worn) are not common.
  • Retained juvenile RR are very worn and faded brown, contrasting to either fresh blackish pre-breeding RR or to intermediately worn post-juvenile RR, or both. Birds with no juvenile RR retained are not uncomon, and the tail is then not useful for ageing.
3cy+:
  • Fresh pre-breeding GC have dark blackish-grey centre with broad grey to greyish-white edges and tips, contrasting to intermediately worn post-breeding GC which have the same basic pattern but has bleached to medium grey and have worn off some of the white in the edges/tips.
  • PC are generally fresher and darker grey than juveniles, but differences are not always obvious.
  • Tips of PP are generally more fresh and darker/denser, but a few are more worn and less easy to judge.
  • Moult contrasts between pre-breeding and post-breeding feathers are often present in tertials and in tail but are not useful for ageing (2cy without any juvenile tertials or RR retained are not uncommon).
2cy May. GC1-4 are unmoulted juvenile in contrast to fresh pre-breeding MC, GC5-10, tertials and SS5-6. The juvenile outer GC are brownish worn with distinct but very narrow whitish edges and tips. [1ET29627]
2cy April, This bird shows three different generations of GC: GC1-2 are juvenile, GC3-6 are post-juvenile and GC7-9 are pre-breeding. Innermost GC10 is post-juvenile, and single coverts that are not moulted in the regular sequence are rather commonly seen. [1ET81193]
3cy+ April. Note the contrast betwen fresh inner pre-breeding GC4-10 (with dark blackish-grey centre with broad grey to greyish-white edges and tips) and intermediately worn outer post-breeding GC1-3 (which have the same basic pattern but has bleached to medium grey and have worn off some of the white in the edges/tips). Note also the inner three GC with a slightly different pattern, creating a 'false contrast'. [1ET29450]
3cy+ April. Note the contrast betwen fresh inner pre-breeding GC5-10 and intermediately worn outer post-breeding GC1-4. [1ES24484]
2cy May. Juvenile PC are usually faded pale brown and worn, but well kept birds are not always easy to separate from adult. [1ES24630]
2cy May, showing variation. [1ES24756]
3cy+ April. PC are generally fresher and darker grey than juveniles, but differences are not always obvious. [1ET29459]
3cy+ April, showing variation. [1ES24484]
2cy May. Tips of PP are often worn, bleached and faded brown (but note the varition shown to the right). [1ES24630]
2cy May. Some 2cy show less wear and may be more difficult to tell from 3cy+ in this respect. [1ET29627]
3cy+ April. Tips of PP are generally more fresh and darker/denser than in 2cy (but a few are more worn and less easy to judge). [1ET29459]
3cy+ May, showing variation. [1ET29539]
2cy May. Longest tertial are fresh pre-breeding while the shorter two are worn post-juvenile (like the visible GC10). Without presence of a juvenile feather the tertials are not useful for ageing. [1ES24756]
2cy April, showing a unifom set of pre-breeding tertials. [1ES24497]
3cy+ April, showing a uniform set of pre-breeding tertials, not useful for ageing. [1ES24495]
3cy+ May. A slightly browner bird, also showing uniformly pre-breeding tertials. [1ET29539]
2cy May. Tails may be rather difficult to assess (esp. separation of pre-breeding and post-breeding/post-juvenile generations, which all can be rather variable in wear). However, separating the mentioned generations is not necessary - it is only the presence of juvenile feathers that help the ageing process (proves the bird as 2cy). In this bird, R3-4 (both sides) and left R5 are juvenile, while the rest, R1-2 (both sides), right R5 and both R6, are either post-juvenile or pre-breeding. [1ES24630]
2cy May, showing variation with right R1-4 and left R4 are juvenile, while the rest of the tail is post-juvenile or pre-breeding. [1ES24756]
3cy+ April. As stated above, separation of post-breeding and pre-breeding generations may be difficult due to variation in wear (and is not needed for ageing). This individual possibly shows pre-breeding R1 and R6 on both sides, while the rest of the tail is post-breeding. [1ET29459]
3cy+ April. Another individual, but the moult is probably identical to the bird to the left. [1ES24495]
More Motacilla alba:
Sexing spring
Ageing autumn
Sexing autumn
Moult
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