i know these kind of 2nd gen coverts from mid winter; see the attached pics from january - not so plain grey but dull with a dark shaft. i concludeed these are later moulted 2nd gen. coverts, not 3rd generation, right? but what about those scaps in the original bird?
The moult process in the scapulars is very difficult to describe, as there is so much variation between individuals, but also because there is so much variation in the patterns. In general, 2nd gen feathers have an anchor pattern, sometimes with some extra transversal bars. This anchor may be obvious, dark brown and broad, but it may as well be ill defined, in which the subterminal line may be almost lacking, leaving a single shaft streak as 'the pattern'. When these patterns are ill defined plus they are pale brown, the pattern may be hard to detect when feathers grow older.
From mid November onwards into the winter, it is pretty safe to conclude that fresh upper scapulars, reckognised by the grey tone, must be 3rd gen scapulars. This is moreover true, when the 'scapular coverts' have been replaced for 2nd gen feathers. These scapular coverts are the longest, rear lower scapulars, laying on top of the tertials, and in 99.9% of the birds, these are the last feathers from the 'scapular region' to be replaced. For S France michahellis, the end of November is more or less the time.
By late November, many birds start subsequent moult wave in the upper scapulars, replacing the second generation feathers for third generation. The last moulted second generation lower scapulars show a brownish or buffish based centre with a pattern of dark bars or anchor pattern. The feathers show a broad white fringe. The new third generation feathers can show various patterns:
- again very second generation-like with anchor patterns but again with warm brown centres;
- a grey base with ill-defined anchor pattern close to the tip;
- plain grey feathers with a dark shaft streak.
Complete grey feathers are very rare, but some 1cy November birds tend to show plain grey, adult-like feathers (e.g. 947X, ringed 1cy michahellis from S France:
http://www.gull-research.org/ylg1cy2cy/ ... ha947x.htm).
Moult in the scapulars seem to be an ongoing process right from fledging to late-November. Scapular moult may continue at a very slow pace during the winter months from December to March, but the major replacements take place until November. This is illustrated by the images in Nov 1cy (
http://www.gull-research.org/ylg1cy2cy/ ... 1cynov.htm), which hardly show a bird with obvious moult gaps in the scapular region.
The extend of this scapular moult is probably strongly influenced by hedging date, but more research is necessary. November 2003, we checked 43 ringed 1cy michahellis in S France, at various locations. About 20% of these birds had all upper scapulars still second generation, without fresh third generation feathers. This figure may be higher (up to 33%) as observation distance was too far in some cases to fully exclude small third generation upper scapulars at the division of the mantle feathers, but third generation scapular scores in these birds must have been low anyway.
About 45% of the 1cy birds in S France had at least moulted some upper scapulars to third generation (45% of the birds fall in class 1-25% scapulars moulted to 3rd generation). Most advanced birds showed an almost completely replaced upper scapular region (2 birds fall in class 75-99% of upper scapulars third generation) and one of these birds even moulted most lower scapulars to third generation (class 50-75%). Not surprising perhaps, this is 947X again.
at least not masses of them to start statistics. so i'm bound to search through pics...