Large white-headed gull, Northern Sri Lanka (1 Viewer)

Hi

I was in Sri Lanka over Christmas. Saw a large flock of gulls, most of which were Pallas' (about 3700 birds) with some that I assumed were Heuglin's (70) plus Brown-headed (500) and some Caspian Terns (100). To help me better estimate the numbers of each species, I photographed the flock in sections so that I could count them later. In the photos I came across this gull that didn't fit the ones I'd been calling Heuglin's. Any ideas?

Photo 1 shows it with the other gulls for comparison.
Photo 2 is the close up
Photo 3 shows what I was calling Heuglin's from further along the flock for comparison

I don't have any other photos of it, I'm afraid, so it's probably not identifiable with certainty.

Many thanks
Ken

the large gull in question looks good for barabensis (steppe gull) with its paler mantle and vivid orange yellow legs. the darker ones are not as dark as western heuglini gets (i think, from these pics), so they might be the so called 'taimyrensis', from the large heuglini x vegae zone (stable hybrid?).

cheers,

On range (and on mantle colour), so many taimyrensis together are unlikely in Sri Lanka. Colour-ringing has shown them to migrate in a south-eastern direction to the Sea of Okhotsk, Korea and Japan (van Dijk et al 2011).
Also, heuglini breeds west of the Taimyr peninsula, and vegae east of it. In Taimyr itself, only one taxon of gull seems to breed, with rather medium grey mantle colour (see e.g. plate 15 in van Dijk et al). No assortative mating was observed, so it is not clear whether there really is a heuglini x vegae zone at all. Perhaps introgression between taimyrensis and vegae is more likely.

The large gull in Ken's first two photos actually looks a lot like these Taimyr Gulls and to some of the gulls seen in Japan, so it is not clear to me if it should be considered a Steppe Gull.

More on 'taimyrensis' here:

http://www.surfbirds.com/forum/showthread.php?8264-Taimyr-Gull-wintering-range
and the paper mentioned by Peter here:

http://gull-research.org/papers/gullpapers1/Taimyr_Gulls_Dutch_Birding33_2011_pag9_21.pdf

There´s no real reason to why Ken´s bird in pic 2 isn´t barabensis (large male). and in pic 3 it seems to be a mix of heuglini like birds and probably a few barabensis. The bird in the foreground with 8 visible primaries suggest heuglini on moult score. On balance, something else might be considered but I agree with Peter that a 'bunch' of 'taimyrensis' on this location seems farfetched.

JanJ

Thanks for replies so far Lou, Smiths and JanJ. It's interesting that large gulls are not recorded frequently in the south of Sri Lanka where the birders concentrate their efforts and yet this very large flock was present in the north near Jaffna. It was not something I was expecting to see. I suppose, barabensis is likely to be a new (although undoubtedly regular) taxa for Sri Lanka and possibly a new species depending on the taxonomy you follow. Not enough in the one photo to claim it, unfortunately. I must find time to re-scrutinise my photos. There may be shots of other birds.

Thanks again.
Happy birding,
Ken

Just found this reference to the white-headed gulls of Sri Lanka;

http://www.ceylonbirdclub.org/articles-2007-10.php

Ken

The BOU stance described in the Ceylon link is about as conservative as you can get.

Steve