Adult Herring Gull with grey tongues penetrating white mirrors

This Herring Gull photographed January 5, 2014 on Grenå Harbour represents an example of one with limited black primary pattern; i.e. it has some degree of Thayer's Gull-like pattern. Although it is somewhat extreme, it is tempting to suggest that it simply represents a part of the spectrum for argentatus. Malling Olsen & Larsson writes in Gulls that a pattern with reduced black is dominant in populations of nominat argentatus breeding in Finnmark and NW Russia, the wingtip can sometimes have even less black than this.

A character often seen in these gulls suspected to be northern argentatus is that they often have rather dark upperparts and a significant string of white pearls due the white spots squeezed in between the tip of the grey tongues and the black primary pattern, e.g. here.

One other thing to note is how the grey primary tongues on the inner webs blend into the white mirror on both P9 and P10 in a degree that I have never seen before.

Note the highly asymmetric primary pattern.

Note how the grey primary tongues on the inner webs blend into the white mirror on both P9 and P10 in a degree that I have never seen before.