[Birdtalk] Re: [Birdnet] re: Another "white-winged" gull in Logan - possible ICELAND GULL?

[Cliff and Lisa Weisse]

Except for the sharply bicolored bill, pot-bellied body, central 
placement of the legs under the bird, lack of attenuated rear (although 
I think some Icelands can show primary extension this short, it's not 
typical-if there is such a think), and more central location of eye on 
head this is a pretty good candidate for Iceland.  I think individuals 
like this are a good illustration of why Iceland and Glaucous are 
usually grouped together in field guides - they are extremely similar in 
plumage.  I also think it's a classic example of why structure is the 
key to identifying gulls despite the fact that it is often entirely 
overlooked.  Fortunately there are structural traits that consistently 
differ between Glaucous and Iceland.

But first, there is a small subspecies of Glaucous so size isn't a 
strong argument for Iceland here.  The "barrovianus" subspecies of 
Glaucous Gull overlaps broadly in size with Iceland.  Measurements from 
Howell and Dunn are 21.5-24.8 for barrovianus and 19-24.5 for Iceland.  
Certainly Glaucous and not be ruled out based on size. 

Structure.  The bill appears quite small in some photos but more stout 
in others so it's hard to judge from these shots but in all it's 
bicolored.  Iceland typically has a more solid black bill, especially at 
this date.  The location of the eye on the head looks a bit further back 
than expected for Iceland.  The position of the legs under the birds 
body appears pretty much centered (front the rear) whereas Iceland 
should have legs positioned further forward (more bird behind the legs 
than in front).  All of these marks are consistent with Glaucous Gull 
and there isn't anything about the bird that doesn't fit that ID and 
that's what I think this bird is, a small Glaucous Gull.  For examples 
of Iceland Gulls this is a good site:
http://www.birdinfo.com/A_Images_I/IcelandGull_image.html

I would also suggest that making comments such as "if the records 
committee wouldn't accept this for a Iceland Gull for Utah, it is 
hopeless" is at best counter productive.  You might not have intended it 
but it sounds like you are dissatisfied with the Utah BRC.  I've been 
watching their decisions for quite a few years and I think they do an 
excellent job, especially so regarding previous reports of "Iceland" 
Gull.  There's a very good reason there are exceedingly few accepted 
records in the western US.  The ID is virtually impossible except for 
extreme petite and pale individuals (ever wonder why none of the 
proposed Icelands in the west are these extreme individuals?) and there 
is no pattern of vagrancy.  As a result records committees regularly 
struggle with this issue (it's exactly the same with Thayer's on the 
east coast) and some will not even review reports.  A good example of 
the other side of this problem is this bird:
http://www.birdinfo.com/A_Images_I/IcelandGull_0014.html
Try to make this one anything other than a Thayer's in Utah.

Good birding and keep the cool gull photos coming.
Cliff

Tim Avery wrote:
> I will go out on the limb here and say, that if the records committee 
> wouldn't accept this for a Iceland Gull for Utah, it is hopeless and 
> this species will never be added to our state list.  This bird looks 
> like a classic Iceland Gull in my opinion, and based off the 
> California Gulls behind, is nowhere near big enough to be a Glaucous, 
> and at worst this may be a Kumlien's type (still considered an Iceland 
> Gull ssp).  However, this bird would seemingly fit the bill for Iceland.
>
> Great lookig bird!  And a nice way to kick-off the winter gulling!
>
> Good Birding
>
> Tim
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-- 
Cliff and Lisa Weisse
Island Park, Idaho
cliffandlisa at octobersetters.com

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