cgeoff

Two things I'd add. Firstly, the narrow second dark band on the tail is something rarely shown so clearly by other taxa. Secondly, note the extensive pale inner primary window. This bird has at least extensively pale inner webs to all but the outer 3 primaries, and even P8 has some pale internally. On vegae, these pale markings do not extend so obviously beyond P5, while on heuglini and Slaty-backed, the wings are more uniform (though the latter, in particular, does often have a paler area on the inner primaries).

Geoff

[ Last edited by cgeoff at 5/12/2009 13:44 ]

cgeoff

Yes, I would say this is also mongolicus - despite not having a second tail band, nor very extensive pale inner primaries (which highlights how variable gulls can be!).

It does have a relatively narrow tail band and a contrastingly pale head, which in my experience is characteristic of 1y mongolicus at this stage in the first winter; it also has a classic bill shape and size. Further, the upper scapulars of the far wing in the first photo are obviously dark, which is a good feature; these remain visible throughout the first winter.

Very good photos. As said above, Mike and I plan a paper on large gulls in HK, and we encourage people to take as many photos as possible.

Geoff