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Caspian or Yellow-legged gull ... Kent, U.K. (2 Viewers)

Wing tip pattern and colour of the iris rule out a Caspian Gull.

not really. unfortunately there exist very pale eyed caspians and a large p10 mirror with broken subterminal mark is actually normal for cachinnans - other than that there is hardly more to tell from wing tip pattern (extent of underwing p10 tongue would be important - any other pics, mick?).
still, this bird looks like an adult winter a YLG on jizz: large head, red orbital, blunt tipped bill, full breast and longish wings. usually adult michahellis have brighter yellow legs even at this time of year, so, together with the large p10 mirror this should be at least a sign for caution - other pics would possibly settle the ID.
 
hi mick,

it's the open wing shots that make it easy - the white tongues on the underside of p10 (outermost primary) are short, about half of visible feather: this definitely makes it a yellow-legged gull. this together with a solid p5 mark and small p9 mirror.
 
Hi,
could be a Yellow-legged Gull, I guess, but the white tertial crescent is fairly broad, and so is the white trailing edge to the secondaries. In addition, the leg colour is rather dull, and the gonys spot is not really extensive nor bright red.
For these reasons, I would also consider a Yellow-legged x Herring Gull hybrid.
See British Birds 105: 530-542 (Sep 2012) for photographs of colour-ringed examples of this hybrid combination.
 
Hi,
could be a Yellow-legged Gull, I guess, but the white tertial crescent is fairly broad, and so is the white trailing edge to the secondaries. In addition, the leg colour is rather dull, and the gonys spot is not really extensive nor bright red.
For these reasons, I would also consider a Yellow-legged x Herring Gull hybrid.
See British Birds 105: 530-542 (Sep 2012) for photographs of colour-ringed examples of this hybrid combination.

Maybe. I have had what appear to be three hybrids at this site this year. But the structure and upperpart colour combined with the white head and red eye ring and stout, short bill all suggest a Yellow-legged Gull. Tertial cresecent is interesting so I will check that out.

The dark smudge on the bill may suggest immaturity.

Most of the Yellow-legs here appear to get brighter legs as the season progresses perhaps.

Cheers, Andy.
 
Maybe. I have had what appear to be three hybrids at this site this year. But the structure and upperpart colour combined with the white head and red eye ring and stout, short bill all suggest a Yellow-legged Gull. Tertial cresecent is interesting so I will check that out.

The dark smudge on the bill may suggest immaturity.

Most of the Yellow-legs here appear to get brighter legs as the season progresses perhaps.

Cheers, Andy.

Big tertial crescents (and big white primary tips) do seem to be reasonably frequent on YLG. I didn't note the exact proportions, but on recent trips to the west coasts of France and Morocco a significant minority showed one or both of these features. May have some photos somewhere, but the YLG in plate 392 in Olsen & Larsson shows both.
Cheers
Matt
 
Big tertial crescents (and big white primary tips) do seem to be reasonably frequent on YLG. I didn't note the exact proportions, but on recent trips to the west coasts of France and Morocco a significant minority showed one or both of these features. May have some photos somewhere, but the YLG in plate 392 in Olsen & Larsson shows both.
Cheers
Matt

Thanks Matt.

Here's an immature with legs that aren't too bright. Taken on Saturday close to the site where Mick photographed his bird.

http://www.kentos.org.uk/gallery/main.php?g2_itemId=5515

Cheers, Andy.
 
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Hi,
could be a Yellow-legged Gull, I guess, but the white tertial crescent is fairly broad, and so is the white trailing edge to the secondaries. In addition, the leg colour is rather dull, and the gonys spot is not really extensive nor bright red.
For these reasons, I would also consider a Yellow-legged x Herring Gull hybrid.
See British Birds 105: 530-542 (Sep 2012) for photographs of colour-ringed examples of this hybrid combination.

Some good points there...

JanJ
 
Thanks for all the links, but the point is that the OP bird just does not look like most Yellow-legged Gulls - even subadults.
Maybe this becomes more obvious when we compare its leg colour with its bill colour. The bill is not particularly brightly coloured, but it is still clearly yellow. The legs, on the other hand, I would describe as very dull yellowish with a distinct flesh tinge - definitely a bit more pinkish than the bill.
This colour difference occurs only rarely in subadult YLG, and in such birds there are usually still some immature wingcoverts and/or primary coverts, while the primary pattern is not fully developed (i.e. shows more black than in full adult).
 
Thanks for all the links, but the point is that the OP bird just does not look like most Yellow-legged Gulls - even subadults.
Maybe this becomes more obvious when we compare its leg colour with its bill colour. The bill is not particularly brightly coloured, but it is still clearly yellow. The legs, on the other hand, I would describe as very dull yellowish with a distinct flesh tinge - definitely a bit more pinkish than the bill.
This colour difference occurs only rarely in subadult YLG, and in such birds there are usually still some immature wingcoverts and/or primary coverts, while the primary pattern is not fully developed (i.e. shows more black than in full adult).

Hi Smiths,

It's not uncommon to find dull legged YLGs here locally. I think it's dangerous to try to suggst that we have hybrids floating about. I'm aware that a couple of recent articles have been published on this subject and it is therefore fashionable.

There are a number of sub-adults/immatures YLGs on gull research that show paler legs and a dark smudge in the bill. Yes, they have added the caveat 'presumed sub-adult' for birds with dark in the bill, but nevertheless, if the subject bird didn't have that dark smudge in the bill, then I'd be more inclined to agree that it is a hybrid.

A bit of googling also throws up YLGs with a wide secondary trailing edge. The tertial crescent more so. The links above prove that.

As the structure and plumage of this bird meets the criteria for YLG, it makes sense, IMO, to assume that this is what it is.

Also note that many of the birds that I personally digiscope in the winter here are in poor light accompanied by light mist. This washes out some colour from images.

Cheers, Andy.
 
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