Herring Gull (argentatus & argenteus)
(last update: February 11, 2013)
Herring Gull (argenteus) NLA 5.417.498 2008, 2009 & 2011, IJmuiden, The Netherlands.
This bird was ringed on June 10 2007, as pullus (in a nest of 3) on Jan Ayeslag, Texel, the Netherlands.
below: Herring Gull (argenteus) NLA 5.417.498 5CY, October 21 2011, IJmuiden, The Netherlands.
P8>P7. Pink base on lower mandible. Small marking on lower mandible.
below: Herring Gull (argenteus) NLA 5.417.4983CY, January 08 2009, IJmuiden, The Netherlands.
It nicely demonstrates the ongoing moult after September (notice fresh feathers), a short period of 'partial autumn moult'. In general, some inner coverts and the upper tertials are replaced again in this process, as are a random number of scapulars. It's hard to tell whether the replacement in scapulars will fall idle completely; probably feather replacement continues at very low pace throughout the winter in these tracts.
Note the replaced upper TT, inner GC and some central MC.
below: Herring Gull (argenteus) NLA 5.417.4982CY, September 19 2008, IJmuiden, The Netherlands.
P8 f.g. P9 halfway. This very moment, the upper TT is dropped and the tip of 3rd gen feather just visible.
below: Herring Gull (argenteus) NLA 5.417.4982CY, August 20 2008, IJmuiden, The Netherlands.
PMS: P7 fg. Note 2nd gen coverts and tertials.