This Gull needs identifying please

[David in Miyazaki]

This Gull was seen the other day here in southern Japan, Miyazaki. Can anyone help me with it please. Thanks The link to the photo is here:

http://surfbirds.com/albums/showphoto.php?photo=5826&cat=542

[Colin Key]

Adult winter Herring Gull for me David.

Colin

[forktail]

I am thinking more on the lines of Vega or mongolicus, and I would plump for mongolicus due to the leg colour, prominent tertial step and white crescent. The bill looks ok with a long, smooth, upper mandible curve and a good gonydeal angle below. The streaking restricted to only the hindneck (possibly a little around the high and well set-back eye) might point towards Mongolian Gull too. It also looks quite a long bird too, a bit like the impression a Caspian gives?

or am I well off the mark Jan?

F.

[Brian S]

When was the exact date of this?

To some extent I agree with Forktail about the structure of the gull, but, enlarged there seems to be quite a lot of streaking around the eye, head and neck - too much for mongolicus. Plus with the primary extension being quite short it hints at vegae, but the legs aren't especially raspberry pink. Could it be some kind of intergrade between vegae and something?

For lots of pics of mongolicus
http://www23.tok2.com/home/jgull/mongolicus/index.html

Brian S

[forktail]

Hi Brian

After opening the 'large' pic (and getting a huge image!) I certainly agree that there is much more streaking visible than is apparent in the thumbnail and even in the larger pic you get from clicking the thumbnail) - more in line with a Vega-type. I had a look in Olsen and found that vegae leg colour is yellowish in eastern birds and pinker in western birds. I presume they mix to some degree on the wintering grounds (with more westerly birds on Kyushu?), so might this account for the less than typical pinky/fleshy/becoming raspberry legs of this bird when compared to an adult Vega at this time? It's perhaps almost impossible to accurately gauge the upperpart tone but Olsen mentions that mongolicus is often paler than vegae but that doesn't really get us far with this bird, I dont think?

As Brian mentioned an intergrade: Would a Heuglin's x Vega produce something like this bird, with less than the usual amount of streaking on the head for a Vega? The upperparts should be darker than a typical Vega but I've only seen a few Vega and from memory, this bird looks within the range of Vega in the photos at least. Am I complicating things and could it just be a Vega?

[JanJ]

Hi all.

I´m also in the Vega camp here and I agree with Brian that there´s more streaking on it´s head than first noted, which in it´s self is a good indication for Vega over Mongolian (and especially at this time of year). Although variable, some Vega - at this time of year - shows fine streaking in the nape area resembling Mongolian, of which many are white-headed at this time of year.
The short primary projection can probably be explained by not fully grown primaries, since Vega is a late moulter compared to Mongolian. It´s not unusual for some Vega with growing primaries in late Feb. In the subject gull p6-8 is visible with p5 hidden under the tertials, usually in LWHG, provided the tertials are reasonably fresh.
Assuming the p-moult score is correct - vote is def. Vega. However the possibilities of an intergrade is also something to consider - although it might be difficult to judge leg colour in this image.
Some intergrades (the so called - according to Yésou - invalid taxon 'taimyrensis') are even later in p-moult compared to Vega, finishing late Feb-March.

Have a look at these: (unfortunately no date on these)

http://starling.dyndns.org/~birdkitahiro/hokkaido/gulls/gullindex/heuglini/index.htm

With dates:

http://starling.dyndns.org/~birdkitahiro/05gurep/top.htm

and many of Vega:

http://larus.hp.infoseek.co.jp/vega.html

JanJ


PS. Had another look at the image, I didn´t click on the image - instead blew it upp, and realised that by clicking on the image it became clearer!
The fine streaking thus becomes more clear but nape area is more spotted than streaked. It also seems to be rather pale-eyed which together with fine steaked head and possible leg-colour might indicate an intergrade. The bill looks big though, many intergrades with smaller bills.

http://www2.kongju.ac.kr/srcho/pintail/2006/feb/2006022201.htm

http://www2.kongju.ac.kr/srcho/pintail/2006/feb/2006020203.htm

http://www2.kongju.ac.kr/srcho/pintail/2006/feb/20060224.htm

[David in Miyazaki]

Brian S was asking for the exact date this bird was seen. It was the 8th Feb 2008, in an inlet by a river estuary just north of Miyazaki City. I have seen Vega Gulls further south before now, and comparing it with some of those photos, it was pretty close, but my identification skills are not very good.