Progression of an individual Yellow-legged Gull from 2W (3cy) to Adult

© A. R. Dean

Images 28 &29.  4cy.  Early October 2011.

(Image 1 in the series is at 20/01/2010).

Old outer primaries now dropped, with new p9 half-grown and tip of p10 emerging beyond primary coverts. Note that new primary coverts are now clear grey apart from small dark mark on outermost. When outermost primaries have fully grown, adult plumage will have been acquired.