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Caspian Gull or Yellow-Legged Gull? (1 Viewer)

Lancey

Well-known member
Dear all,
I've attached photos of an adult/4w gull which I'd identified as a Yellow-Legged Gull when I saw it on 23rd December 2005. This identification was based upon the tone of grey on the upperparts (judged as being close to that of a graellsii Lesser Black Backed Gull) , the brightly coloured bill and the structure of the bird. Unfortunately the gull was in water deep enough to mask the leg colour so these features were all that were available to me to make an idehntification.

When I looked at the video of this bird a few days ago I was surprised to see that it did in fact reveal its leg colour when scratching its head and it was pink rather than the yellow I'd expected. So, was it in fact a Caspian Gull? If so, the dark upperparts and bright bill don't seem to fit although the bill is quite parallel sided and 'pencil-like'. The eye is also slightly dark. Somehow it just doesn't seem right for a Caspian Gull in my opinion.

What do you think?

Regards,
Lancey
 
YL Gull

Dear all,
I'd agree with Yellow-Legged Gull myself since that's what I'd identified it as originally, it was the lack of obviously yellow legs that threw me. However, I expect it is possible for a YLG to have pinkish instead of yellow legs (variation is the rule in gulls after all.

Lancey
 
Hi Lancey!

Caspian, Yellow-legged, or Herring (argentatus) is the question!
One thing that bothers me, being a YL, is the short primary projection, primaries do look fully grown (they should be at this time of year), you can just see p10 slightly outside p9, and the greyish pink legs, although legs, and fet, can look like this. Question is if the gull is an adult, if we only could see the primary coverts ( and of course the whole wing), usually level with the tertial base on a standing bird, or as in this case, pic. 2 on the water, but I´m not sure if there´s some dark p-coverts visible there, as there´s no pale tips visible, like this (http://www.gull-watching.com/photo-127433-micha54-1_jpg.html).
To make a long story short, acceptable for a Yellow-legged Gull, probably a 4cy.
It´s btw not a Caspian gull, for varies reasons, but have a look at this male Caspian bill:
Taken in Sweden by Swedish birder David Erterius on 11 Nov this year.

http://www.artportalen.se/artportalen/gallery/images/swe/birds/2006/large/6614.jpg

http://www.artportalen.se/artportalen/gallery/images/swe/birds/2006/large/6613.jpg

Notice the primary pattern, small dark eye and the less curved bill tip comp. to Yellow-legged.

JanJ
 
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YL Gull

JanJ (and all contributors),
Thanks for your comments. It looks far more like a YL Gull than a Caspian that's for sure. There have been no votes for Caspian so I'm pleased that my initial identification was the right one. It was the leg colour that gave me a moment of self-doubt.

Lancey
 
the bird seems to be not fully adult (4th cy? as suggested), though there is quite a big white mirror on p10 (seen in pic 3 , when scratching and in 2) but it is not connected to the tip, which is also tentatively in favour of ylg. didn't you catch this bird in flight, lancey? what a pitty. but these pics are better than those of earlier ylg-candidates... :D
one thing i was wondering. if that's really a pinkish or at least fleshy leg. i haven't seen (adult) ylg michahellis having not at least a good tinge yellow, even in december. jan, do you have a gulllink 8-P to such a biest?
can we exclude caspian definitely just on structure and bill, that's what i ask myself. :eek!: well, it "looks" like yelleg gull
again an interesting bird lancey! how do you attract them? :smoke:
 
Hi Lou!

Probably a majority of pink, or better, flesh- legged Yellow-legged gulls are not fully adult. The occasional adult turns up with fleshy fleshy-grey legs, and the ones I´ve seen where in the non-breeding period, and they had a sligt yellowish tinge to the legs, a trifle brighter on the feet.

http://www.gull-watching.com/photo-127433-micha29_jpg.html

http://listserv.arizona.edu/cgi-bin/wa?A2=ind0301a&L=birdwg01&T=0&O=A&P=1814

According to the exclusion of a Caspian Gull on structure and bill alone, no we can´t Lou. There´s however a primary pattern, upperpart darkness to consider when looking at the subject gull. I suppose you don´t get a Caspian feel when you look at Lanceys gull Lou, but the sometimes hard to describe in words differences, is more obvious to the eye, as I´m sure you would know of course.

JanJ
 
Caspian versus YLG

Lou and JanJ,
I'm pleased that it isn't just me who finds this gull tricky to identify with certainty. Unfortunately, in answer to your question Lou, I didn't see the bird wing stretch - I have looked hard at my video to see if I had the wing pattern somewhere but unfortunately I don't.

A feature that seems to confuse the issue is the bill shape which seems more Caspian-like than YLG-like, although I'm sure that YLGs can have Caspian-like bills and vice versa.

When it is on the water it does look more like a YLG than a Caspian in my opinion. It's a pity that tricky gulls like this one don't seem to get included in gull identification articles which generally deal with the more clear-cut examples. But, that's the trouble with gull identification,there is a lot of ground to cover!

Lancey
 
Hi Lancey.
I wouldn´t say that your gull has a more Caspian like bill. Of course bill shape varies, just look in to a big crowd of Herring Gulls and you´ll see. Our conception of a "Caspian Gull bill" is fairly accurate, the slender bill with a less drooping tip and less pronounced gonys angle, compare with the Yellow-legged:

http://www.gull-watching.com/photo-127428-cach50_jpg.html

but males can contradict that:

http://www.gull-watching.com/photo-127428-cach40_jpg.html

If you look at the Caspian Gull from Sweden in #7 you´ll see that the more gently slooping tip. Your gull, although the tip is slightly blurred, has a more strongly curved tip.
As mentioned, bill size/shape varies, and not every Yellow-legged shows the classic curve to bill tip:

http://www.gull-watching.com/photo-127433-micha18_jpg.html

Also notice the leg colours on these:
http://www.gull-watching.com/photo-127433-micha55_jpg.html

Many non adults of Yellow-legged are difficult to identify, but they do often share the characters, like leg lenght, bill shape and structure with adults.

JanJ
 
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