Primary pattern variation in individual European Herring Gull – 2014 update

Since 2009 I have been keeping track of the primary pattern of an adult European Herring Gull which I observe on a regular basis each year. It was fitted with color rings back in 1986 when it was a juvenile so it is easily identifiable and it also means that we know its exact age (he’s currently in his 29th calendar year). [Edit: 2015: based on measurements taken when ZDGA was re-ringed as Green FAMA, it turned out to be a female]

17 May 2014, Leiden, the Netherlands. European Herring Gull ringed as (Black D)/Green A.

Last year I decided to compare the primary pattern of each moult cycle of this gull of the years in which I observed him to see if any differences could be detected. It turned out that there were indeed differences, albeit minor ones (see Primary pattern variation in individual European Herring Gull).

This year I have been able to take additional photos and compare the current primary pattern to that of previous years.

Two things stand out:

The most noticeable change is once more to do with the size and position of the small mirrors on P9.
There is no black mark on the outer web of P5 in the right wing.

In last year’s post, I kept track of the pattern of the mirrors on P9. Here’s the updated version:

Calendar year*	Left wing	Right wing
24th	Outer web only	None present
25th	None present	Inner web only
26th	Inner web only	Inner web only
27th	Inner web only	Inner and outer web
28th	Inner web only	Inner and outer web
29th	Outer web only	Inner and outer web

* The calendar years actually represent the moult cycle that was completed at the end of the previous calendar year; I’ve decided to refer to calendar years instead of moult cycles (in the 29th calendar year the 28th moult cycle was scored) for readability reasons.