10cy LBBG 10cy adult AM0,
April 16 2001, Missouriweg Maasvlakte, the Netherlands.
An adult, ringed at Maasvlakte as pullus at the nest, June 28 1992. Now in 9th summer (10cy) plumage.
The elegant impression advocates a female.
Apparently this is the brown hue as can be seen in 10cy LBBG in spring. Compared to immatures (5cy and younger), the difference is very hard to tell.
Note the red gonydeal spot, which is confined to the lower mandible and the bill, lacking black marks.
The primaries don't have particularly large white tips, so small tips in Dutch intergrades doesn't necessarily refer to immatures, elder LBBGs may show small tips as well (but the mirror on p10 is well-developed!).
AM0 was not recorded before. Note that the orange colour of the ring faded out to dirty grey.
LBBG 11cy AM0, Missouriweg - Maasvlakte, the Netherlands, April 29 2002.
An adult bird ringed left orange AM0, ringed as pullus at the nest, June 1992, now 11cy. After a few years, the orange ring turns brownish. The dark clouded wash over the under-parts is caused by bathing in contaminated pools near the industrial coal complex. Spring 2003, this female was present at exactly the same nesting site again in the colony at Maasvlakte, near Rotterdam, the Netherlands.
LBBG 13cy AM0, Missouriweg - Maasvlakte, the Netherlands, April 29 2004.
Again present in 2004, now 13cy. After a few years, the orange ring turns pale brownish. Spring 2004, this female was again present at exactly the same nesting site in the colony at Maasvlakte, near Rotterdam, the Netherlands and produced 3 eggs. Breeding success not certain as there has been severe predation in May and June long periods of rain (adults have problems to find sufficient food and start predating eggs and pulli).