Spain, August 2010

[Neil Morris]

I'd be interested to receive any comments about the age (and ID) of this individual photogrpahed in Catalunya, Spain this summer. Thanks,

[lou bertalan]

hi neil,

it's a 1cy yellow-legged gull allright, mostly in juvenile plumage, with an abnormal bill colour and a slightly odd greater covert pattern. but everything else makes it a good michahellis.

regards,

lou

[Neil Morris]

Thanks Lou.

Given the location that seemed the appropriate conclusion but I was struggling to convince myself it wasn't an odd Great Black-backed, with an equally abnormal bill or age stage. It seems a very extreme YLG given the many other YLGs it was in company with. The birds in the background I take to be Yellow-legged Gulls too.

I've posted another image of birds that were in the next group to the above. All YLGs?

I have looked at YLGs on the west coast of Spain and Portugal and found the usual great variation, but usually along three themes. 1) Larger more robust YLGs, 2)those that are more slender, longer-winged types (with subtely different grey upperparts) that I took to be cantabricans - see the other photo posted below, 3) and the very occasional bird where I suspect a Macronesian origin (dark hood, etc).

I've also attached an image of a bird from Essex, England this autumn which I initially considered might be a YLG, but then concluded it was a GBBG.

Lots to learn still.

[lou bertalan]

hi neil,

some male YLGs can have a jizz similar to GBBG with a similarly strong bill. note tertial pattern in your initial bird, GBBG usually with much more white in them; http://www.gull-research.org/gbbg/gbbg1 ... 1cyaug.htm also ground colour is warmer in YLG. bill colour aberrations are pretty common in immatures of all large gulls sp. although i haven't any august 1cy YLG with such an extreme bill yet.

variation in sizes of your spanish birds are probably more due to gender (males being consistantly larger and more powerfull than females) than to subsp. your adult bird (2nd pic) looks like a fairly normal female mediterranean michahellis.

also your last bird seems to be a YLG, note again tertial pattern and many 2nd gen scapulars in august - which is unliklely in GBBG. bill looks too slim on base either.

cheers,

lou

[Cristian Mihai]

I don't see any GBB Gull...

[Neil Morris]

Interesting comments, Lou. Thanks.

By the way, what the photograph of the YLG from Peniche doesn't convey is how much it stood out from all the other YLGs in stature, structure and upperpart colouration. It really was distinctively different from the hundreds - large and small - that were present; though I take the point that it's as likely to be intra-specific variation as it is to be racially different.

Thanks again.