Am I just a little RBGU?

[MzSisyphus]

This bird was observed among RB, (various ages) HE and imm. GBB gulls on the shore in Weymouth, MA. Knowing the frustrations of gull ID, I snapped about 1,000 photos (almost!) Please view them here. . .

http://picasaweb.google.com/MzSisyphus/PosMewCommonGull101408Noon#

I'd appreciate your comments.

Kathy V
Weymouth MA

[MzSisyphus]

http://picasaweb.google.com/MzSisyphus/MoreMysteryGull#

[Brian S]

Kathy

Not a typical RBGU, only possibly a Mew/Common.

As a 2nd winter, this bird has odd dark areas in the tertials and spots on the tail for Common (canus), but not unknown and generally when dark in the tertials is present then some black in tail is also.

Points for Mew (brachyrhynchus), the pale eye, and smudgy marks on the flanks are ok, as are the black areas on the tertials and tail.

But is the mantle too pale for Mew? It looks pale enough to be RBGU....

Don't know if I am prepared to go further than poss Mew/Common or prob RBGU, though JanJ might help...

Brian S

[Johnny X]

Looks most like a weak billed Ringer to me. Such birds do occur, although hybrid theories are sometimes invoked to explain them on this side of the Atlantic...

[JanJ]

Hi all.

I had a look at this when it appeared today at Birdforum. My immediate impression was that of a small-billed Ring-billed Gull. Mew mantle shade (approx same as Common, KGS 5,5-7,5 - Ring-billed 4-5). Also in some images, eye looks whitish. However one should be aware of the diffculties judging mantle shade in images, although the gull in question does give the impression of a paler gull than Mew, more like RBG. :err:

Some impressions of Mew:

http://www.pbase.com/jpkln/mew

and others:

http://keenbirding.com/Winter06/KamGullpage.html

Common:

http://www.gull-research.org/canus/commongull.htm

BF.
"I have a lot of Ring-billed feel on this one, although a rather small-billed one. Structurally (check pic. 26) - head shape and the seemingly lack of white tertial crescent, finely spotted nape on a pale head and marked gonys angle suggest Ring-billed over Mew. Dark tertial markings (of variable size) can be seen in both Mew, Common and Ring-billed".

JanJ

[MzSisyphus]

FYI, most of the shots of the "mew-billed" (hey, I kinda like that):smile: were taken at high noon. However, my impression in-person was that the mantle was, indeed quite pale, however, there were RBGUs with lighter and darker mantles. Among the ringbilled,* herring and laughing gulls, it wasn't so much mantle color that caught my eye, it was size, bill shape/color and personality (do we still use "jizz" for that?) :puzzled: "dainty female" were the descriptors that came to mind.Would an in-flight view be diagnostic? I could try for that tomorrow.

And, of course, thanks for the participation and opinions.

Gull ID is a great example of the necessity of collaboration amongst we who bird.
Kathy V

[AndyB]

Immediate impression gives the feel of a small-billed Ring-billed Gull - maybe a little bit big-billed for Mew and lacking that rounded head jizz of that species but that's not very scientific I'm afraid.

video of some Mews and a Ring-billed here:
http://surfbirds.com/video2/view_video.php?viewkey=41366a4bbe8a49b02a02

[Johnny X]

Would an in-flight view be diagnostic? I could try for that tomorrow.

A view of the spread wing tip would be helpful!

[MzSisyphus]

Thanks for all the input. I pared down the photo gallery to avoid confusion. . . some smaller RBGUs snuck into my upload. If there's any local interest (Weymouth, MA, Wessagusset Beach) I'll be there around Noon today.

The "resident" gulls recognize my vehicle and are quite tame.

Kathy V

[MzSisyphus]

More thoughts re: mantle color: I've spent a few hours poring over video and photo evidence of mews and common gulls. Even taking into consideration that the "mew-billed" was photographed at high noon on a very bright day, it does appear that her mantle is not even close to what it "should" be.

On this side of the pond, our Lesser black blacked and laughing gulls approach the shade of gray that most closely approximates actual "mew" mantle shade, based on my photo/video views.

And, of course, it almost goes w/out saying that "my" definition of a dark mantle will not necessarily agree with yours. . .that phenomenon is not rstricted to birders, either!

I sure do appreciate the teamwork that is involved in all IDs, most especially Larus.

[MzSisyphus]

http://picasaweb.google.com/MzSisyphus/Headtohead#5257768549158729186

Thought this might be illuminating. . . Head to Head RBGU / Subject bird

[Josh Jones]

Yes, just a slender-billed individual, but a Ring-billed Gull all the same