Viking or pure Glaucous?

[Peter Stronach]

Hi all,

just wondering whether you could give opinions on the attached photos. This is a 2CY gull that has been reported as a Glaucous Gull and has been at Ullapool on the west coast of Scotland since the 2015/16 winter and is still present. The new scapulars, the bill pattern and the breast feathering seem strange to me, and I was wondering whether it is a Viking Gull?.

All photos are taken this year and are dated so you can see the progression, thanks for any help,

Peter Stronach

[marsmuusse]

Hi Peter,

I opted for pure Glaucous at the very first glance of the first image, due to the overall plumage colour and small beady eye centrally placed in the head. However, I don't think it is pure. The dividing line on the bill is rather blurry and the pattern plus extent of moulted 2nd gen scaps recalls Herring. Also there seems to be a bit too much patterning on the primaries, although this is variable in Glaucous and darker birds are all over the web.