top: LBBG 11cy AH1, Missouriweg - Maasvlakte, the Netherlands, April 29 2002.

An adult male ringed left orange AH1, ringed as pullus at the nest, June 1992. This bird is now in 11cy. June 1992 was the first year that orange rings were used on the Maasvlakte. These 10 year old rings have turned grey-brown over the years, as the pigmentation deteriorated influenced by sun light. Note the slight wear in the tips of the outer primaries.

Ringed AH1 right orange. Probably a male, told by the robust posture. Ringed at the nest at Maasvlakte June 23 1992, now in it's 9^th summer. Note the many brown feathers in the upper parts. In many cases, it's hard to tell whether brownish hued feathers are indications for immaturity or whether they just refer to (one year) old feathers, which have to be shed soon.

After a few years, these orange rings turn greyish.