Dave,
   Thanks for noting the error in my statement about the range of nominate Iceland Gull (glaucoides).  I meant to say that it is rare west of Greenland, not Iceland.  It breeds in Greenland.  It does occur in eastern Canada and rarely in New England.
   The real question is whether glaucoides, kumlieni, and thayeri are one species, as treated by Godfrey in The Birds of Canada; glaucoides and kumlieni are one species and thayeri another, as currently done by the AOU; kumlieni and thayeri are one species and glaucoides another as suggested by someone else; or worse, they are three different species.  In the past thayeri was even considered a subspecies of Herring Gull.  Short of collecting and testing specimens we probably cannot solve it locally.

Bob Ringler
Eldersburg MD

 
---- Mary Ann Todd <> wrote: 
> Followers of this thread will be interested in the gull from NH, DEC 2004, 
> somewhat larger-billed, slightly darker, but similar stage of molt. There was 
> lots of discussion on the NH bird chat site. No consensus of course, but some 
> expert opinion that it was a dark Kumlien's or intergrade.
> 
> 
> http://keenbirding.com/Gulls/KumorThayerGull1.html
> 
> 
> Somebody else on this thread pointed out that virtually all Iceland Gulls in 
> MD (it is thought), and even places like NF, are race kumlieni. Proving that a 
> bird is a nominate glaucoides from Greenland would be hard. Over the years I 
> have seen dozens of these birds in the DC area. Perhaps one in twenty seem 
> like fairly good Thayer's candidates (though not proven as such). Another 7 or 8 
> make one think of Thayer's, but are "whacky looking" in one way or another. 
> The rest seem to fit Kumlien's, looking like birds photographed in NF. I don't 
> know if cline is the right term to use, but there seems to be a lot of 
> intergradation going on. 
> 
> I used to wonder why they could find such seemingly perfect Thayer's Gull 
> candidates even in Ireland, while in MD most candidates for Thayer's seemed a bit 
> dodgy in one way or another. Then I looked at globe and saw that Ireland is 
> closer to the core breeding range of Thayer's Gull than MD is!
> 
> The Kumlien's Gull at Little Seneca reservoir was not the schoolhouse pond 
> bird. It was somewhat paler, with dark markings on perhaps three outer 
> primaries. The small bill size of the Schoolhouse bird may just be because it is very 
> young. Among Herrings and Ring-bills you can very rarely find 
> juveniles/first-winters with ridiculously tiny bills. 
> 
> Dave Czaplak