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