Not possible to age due to complete pre-breeding moult in both age classes. A few individuals retain single (or some) feathers during the pre-breeding moult (e.g. SS or GC), but these are usually not possible to use for ageing since the very same feathers are said to previously have been included in the post-juvenile/post-breeding moult (Jenni & Winkler 1994). A few birds also show other anomalities (e.g. PC that are more worn than GC, or minor difference in wear between groups of GC) but such are probably best explained by differentiated periods of moult during winter.
2cy+ May. Whole wing pre-breeding. GC8-9 appear slightly more fresh than the rest. It may not be possible to explain this with certainty, but could also be a result from differentiated periods of moult. [CP45913]
2cy+ May. All coverts are likely pre-breeding, but the fresh GC10 (as well as a few fresh MC) was likely moulted later during winter than the rest of the coverts. [CV04129]
2cy+ May. Assessing the feather generations are not always easy. In this case the tertials are clearly older than the pre-breeding SS, but it is difficult to say wether the tertials are retained post-breeding/post-juvenile feathers or from an early pre-breeding moult. [CV03579]
2cy+ May. Another complex individual showing variation. [CV04129]
2cy+ May. Pre-breeding PC, but the rather heavy wear indicates that they were moulted in early winter (contra the more fresh GC). [CS02423]
2cy+ May. A fresh and uniform pre-breeding tail. [CV03580]