[magpiemick]

Hello all,

Yep I need your help again, I found this bird today which has confused me just the same as before ...

Mixed features or so it seems !!

http://birdingthedayaway.blogspot.co...-crayford.html

Maybe Caspian need some guidence ..

Attached is a image with more via the link ..

Thanks

Mick ..

[Cristian Mihai]

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

[Cristian Mihai]

For comparison see adult Caspian Gulls in basic plumage:
http://lou.bertalan.de/gulls/m_grp.p...0%28jul-dec%29

[magpiemick]

Thanks Cristian, I will take a look at the link ...

[lou salomon]

Originally Posted by Cristian Mihai

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.

[magpiemick]

Hello Lou,

Thanks for your reply, there's more images via the link ...

http://birdingthedayaway.blogspot.co...-crayford.html

Mick ...

[lou salomon]

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.

[Cristian Mihai]

Originally Posted by lou salomon

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.

[magpiemick]

Thanks to you both, always good to learn more of gull i.d's ..........

[smiths]

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.

[Cristian Mihai]

I would agree with smiths - I really don't see how we can rule out a hybrid YL Gull x Herring Gull.

[tittletattler]

Originally Posted by smiths

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.

[SW London birder]

Originally Posted by tittletattler

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

[tittletattler]

Originally Posted by SW London birder

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/mai...g2_itemId=5515

Cheers, Andy.

[Cristian Mihai]

Where is the pic, Andy?

[tittletattler]

Originally Posted by Cristian Mihai

Where is the pic, Andy?

D'oh! Put the link in now mate. Taken from the 'Gulls' thread.

Some more links:

http://gull-research.org/ylgadsubad/.../micha6651.htm

http://gull-research.org/ylgadsubad/.../micha6742.htm

http://gull-research.org/ylgadsubad/.../micha5308.htm

http://gull-research.org/ylgadsubad/.../micha5290.htm

http://gull-research.org/ylgadsubad/.../micha5358.htm

http://gull-research.org/ylgadsubad/.../micha7383.htm

http://www.gull-research.org/gbbg/gb...g3cynov01.html

Cheers, Andy

[JANJ]

Originally Posted by smiths

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

[tittletattler]

A few more links to YLG:

http://www.cambridgebirdclub.org.uk/...GNKICX1029.jpg

http://3.bp.blogspot.com/_uYdLH-IM33...++IMG_9739.jpg

Compare this:

http://gull-research.org/ylgadsubad/adapr/april03.html

To this:

http://i932.photobucket.com/albums/a...21120_0048.jpg

Note the square back of the head and typical YLG structure here:

http://i932.photobucket.com/albums/a...21120_0043.jpg

Worth looking at this link again:

http://gull-research.org/ylgadsubad/.../micha7383.htm

Cheers, Andy.

[smiths]

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).

[tittletattler]

Originally Posted by smiths

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.

[smiths]

Andy,

I am not suggesting that every odd gull is a hybrid, just keeping an open mind about a bird like this.
Yellow-legged Gulls have been pairing up with Lesser Black-backed Gulls and, to a lesser extent, Herring Gulls in the Netherlands yearly since 1987 and in Belgium since 1996. The hybrid offspring they produce also return to the colony when mature and produce backcrosses. Nowadays, about 10 YLGulls breed annually in the Netherlands, usually in mixed pairs. In Belgium, about 3 to 4 YLGulls interbreed, and about 10 hybrid gulls pair up with other gull species each year. Spain now has a small population of Lesser Black-backed Gulls too, and these birds regularly pair up with the local Yellow-legged Gulls. For instance, there were 17 mixed pairs on the Berlengas in 1996. I do not know the situation in France, but I do not see why it would be any different. Interbreeding is also going on in the UK, by the way.

Therefore, I think it is not too unreasonable to keep an open mind.
Also, I would plead for studying Yellow-legged Gulls not just on local patches but also in the breeding range, summer and winter. Maybe you have? I certainly have, and the OP bird looks a bit dodgy to my eyes - that is all I am saying.
I fully realise that the discussion is a bit pointless since the bird is not wearing a ring, so we can never be sure about its identity.

[lou salomon]

hi peter,

i was always wondering why hybrids (mich x tatus) have broader tertial and secondary crescents? broader than both parents? also, i have to confess that i have difficulties in seeing the differences. usually YLG have slightly narrower tertial crescents but these are minimal differences? same goes e.g. for the white primary tips which are also varying: YLG usually with smaller ones than herring but some have large tips too.
on balance, i agree that the OB here has enough oddities to be assumed a (possible) hybrid

[smiths]

I do not really know why, but the fact is that some hybrids (though far from all!) have rather wide white tertial and scapular crescents.
I agree that this is a subtle character, most useful perhaps in the colonies in spring, as the white tertial crescent of YLG appears to be more prone to wear and therefore becoming thinner then.

[tittletattler]

Originally Posted by smiths

Andy,

Therefore, I think it is not too unreasonable to keep an open mind.
Also, I would plead for studying Yellow-legged Gulls not just on local patches but also in the breeding range, summer and winter. Maybe you have? I certainly have, and the OP bird looks a bit dodgy to my eyes - that is all I am saying.
I fully realise that the discussion is a bit pointless since the bird is not wearing a ring, so we can never be sure about its identity.

Thanks Peter. The stats are useful too.

Yeah, I can happily agree with what you (and Lou) have said.

I think you raise a good point regarding recording (images). This is something I should be doing, I reckon, on a website. Steve Arlow does this locally to a degree but other larophiles in SE England don't to a greater degree.

Whilst looking through the few images of gulls that I do have to hand at work, I found this image of a hybrid from winter 2006/07. Looks like many an Azorean! But it is a hybrid.

Note the leg colour on the LBBGs are dulled by the poor light/weather/camera.

Cheers,

Andy.

Edit: guess the leg colour of the hybrid - I'll post a pic showing the legs on monday :-)

[Cristian Mihai]

Andy, I suppose that your bird is a hybrid LBBG x Herring, isn't it?