Herring Gull (argentatus & argenteus)
(last update: February 11, 2013)
Herring Gull (argenteus) Y.CAX 4CY, May, August & November 2016, IJmuiden & Katwijk, the Netherlands. Picture: Maarten van Kleinwee & Mars Muusse.
Originally ringed only metal NLA 5.332.839, ringed as pullus on July 02 2007. In 2012 trapped again: ringed Herring Gull green YBAJ, ringed as breeding adult on May 07 2012 at Forteiland, IJmuiden. Ringed by Fred Cottaar ringing team.
below: Herring Gull (argenteus) Y.CAX 4CY, November 16 2016, Katwijk, the Netherlands.
Some black on the bill.
below: Herring Gull (argenteus) Y.CAX 4CY, August 05 2016, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee.
Note bill pattern! A dramatic change.
This gull was caught as a breeding male in the gull colony of IJmuiden Forteiland, the Netherlands in May 2016 and ringed as Green Y.CAX.
In May, the bill showed sub-adult features with much black in the lower and upper mandible, a dark yellow base and a pale tip, typical for a Herring Gull of this age.
In August (so after the breeding season), the bill looked very mature with only a small remnant of black on the bill.
In October (and photographed in November), the bill has turned very immature with a pale pink base, a distinct black band across the bill and a yellow tip.
below: Herring Gull (argenteus) Y.CAX 4CY, May 2016, IJmuiden, the Netherlands. Picture: Maarten van Kleinwee.
Clearly sub-adult when trapped at the nest and ringed.
