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great black backed gull or yellow legged gull, Netherlands March 29 (1 Viewer)

Geert Custers

Well-known member
Sorry for the poor photos but is there anybody who dares to say anything about this gull.
Was thinking on a 2 CY yellow legged gull or possibly a great black backed gull.

Best regards,

geert Custers Large gull 2CY.jpg Large gull 2CY B.jpg
 

Alexander Stöhr

Well-known member
Hard picture, at least for me it is, but:
inner primaries seemsto show the venetian-blind effect in such a good shape, that this would be unusual for a YLG
underwing seems to be very palw , even whitish. Yes, this can be explained by slightly overxposure and strong light washing out any pattern there
narrow, neat and clear cut tail band
seems to be very white bodied and white headed (difficult to judge with this pictures). Are there more pictures showing head-sides, where it is possible to judge position of the eye, bill and any streaking to head-sides and crown?

Yes, greater coverts should be darker in an ID-book 2 cy (or a 3cy?) Caspian Gull, but this the best fit to me.

I hope for others to jump in and confirm or correct me
 

Geert Custers

Well-known member
Thanks Alexander,
Indeed photos are lacking some detail and whites are overexposed which i wasn't able to recover anymore.
These are the only 2 photos available.
Concerning the inner primaries, I see it quite often on YLG to to this extent.
In a Caspian Gull I would expect even stronger contrast.
But maybe shouldn't have ruled out that one yet.

Regards
Geert
 

Alexander Stöhr

Well-known member
Hello Gert,

yes, I am not the expert for large Gulls (and far away from judging variation),
but the first winter YLG I see in SW-Germany has either quite dark inner primaries (sometimes to such an extent that I struggle to think its not a LBBG) or more rarely uniform quite pale ones, without such strong contrast between blackish inner web and pale outer web (thus resulting in a strong venetian blind effect). like in your bird (yes weak venetian blind effect is sometimes (regular?) there).

But again: thank you for commenting, very helpful to me, as its still time for me to learn about variation and ID of large Gulls. I have put the text where I am not so sure in italics and hope for more comments, so I can learn.
 

Geert Custers

Well-known member
Not a GBBGull on size alone?

A little awkward but if it is behind the Cormorant in pic 2 ... has to be, surely.
It surely looks big.
But enough to rule out YLG?
Note that GBBG is rare in our region so don't have much size comparisons sofar.
Regards,
Geert
 
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dantheman

Bah humbug
It surely looks big.
But enough to rule out YLG?
Note that GBBG is rare in our region so don't have much size comparisons sofar.
Regards,
Geert
Well, compared to Cormorant, Herring Gull (comparable to Yellow-legged) would look smaller ... this seems to be the other way around.

Great Black-headed Gull (Pallas's) can be ruled out?
 

Parker

Uncomfortably Numb.
Hard picture, at least for me it is, but:
inner primaries seemsto show the venetian-blind effect in such a good shape, that this would be unusual for a YLG
underwing seems to be very palw , even whitish. Yes, this can be explained by slightly overxposure and strong light washing out any pattern there
narrow, neat and clear cut tail band
seems to be very white bodied and white headed (difficult to judge with this pictures). Are there more pictures showing head-sides, where it is possible to judge position of the eye, bill and any streaking to head-sides and crown?

Yes, greater coverts should be darker in an ID-book 2 cy (or a 3cy?) Caspian Gull, but this the best fit to me.

I hope for others to jump in and confirm or correct me
I’m not confident at all but I had the same thoughts as Alex before reading his post.

Happy to be corrected of course.
 

Alexander Stöhr

Well-known member
Thanks Geert and Dantheman,
a GBBG didnt came int my mind with a complete, unbroken tail-band. But I am far from the expert, and Gulls is defintely a field where I must gain more experience!

A 2 cy Caspian Gull (sure ID, as this bird was posted somewhere else, and no correction came. Thanks to all!) from 12.03.2020 (Wusterwitzer See NE-Germany)
https://flic.kr/p/2kXpPxk
 
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