2nd CY gull | 5 March 2020 Choshi harbour, Japan (1 Viewer)

[HouseCrow]

Here we go again.. After my Thayer's refind has been approved (at observation.org) I keep looking for id´s. This not so very well documented 2CY gull I saw speeding past near the river mouth at Choshi. It looks to me quite a bit like other Glaucous-winged Gulls but I think the photos do not show enough detail to exclude other species, or hybrids.
Could you perhaps tell me your thoughts?
Note that Glaucous-winged is not irregular in Japan, but not common in these more moderate waters (commoner around Hokkaido)

hope to hear from you
record observation.org: Glaucous-winged Gull - Larus glaucescens 2020-03-05 | Japan (moderated records)
record inaturalist: Glaucous-winged Gull (Larus glaucescens)


Mind: I am definitely ok with the status non-identifiable, I would like to know some background...if you can easily provide it that is...

My note: It looks ok-ish for 2nd CY GW Gull but the undertail does not show to be mottled. I am not sure if that should have been visible.

cheers
Gerbe n

 

[Indobirder]

If I had seen this bird in BC (Canada) I would write it as Glaucous-winged.

I think the undrertail pattern would not be visible since the photo is somewhat blurring the bird. The lack of contrasting primaries is what makes me agree with your ID, however I am unfamiliar with the Gulls in your area 🙂

I also default to GW where I am despite most having at least some hybridization going on.

 

[HouseCrow]

Thanks Indobirder,
In my true area (Western Europe) Glaucous-winged is extremely rare. A friend and his friends found one in Morocco a long time ago... That was one of the first in our area. In Hokkaido I know it is a regular, further south it is less common but not rare. I have only been to mid and south Japan, in early and late spring so my experience with the species is nil, unless this is one. The fact that (I think) Peter Adriaens has not corroborated the record on observation.org makes it a definite uncertainty but I wondered if i am way off with my suggestion or not... you confirm that i am not way off...thanks for that!

cheers
Gerben

 

[HouseCrow]

ID as 2CY Glaucous-winged Gull confirmed by admin on observation.org.