Dintelhaven - Maasvlakte, the Netherlands, April 29 2002.
An adult bird ringed left green EAK5, ringed as pullus at the nest, June 24 1997, now 6cy. The primary tips are fresh and the broad p10 mirror reaches the edges of the feather over a long range. P9 has a white mirror as well, although its a female. In the median coverts, the difference can be seen between the recently moulted feathers (which are plain grey) and the older, brownish feathers with wear in the fringes. Note the dark spot on the upper mandible.