Some other points:
1) Adult Thayers seem to have relatively shorter legs than the other
herring/ gwg/ westerns.
2) Light-eyed Thayers still have purple-pink eye-rings, very unlike
herring's yellow eye-ring.
3) The black on the primaries of ad. Thayers is largely restricted to the
outer webs (and subterminal area) and is minimal on the inner webs. I think
that this is more so than on the confusing dark primaried GW.

Nigel Ball (nball001 at msn.com)
Bainbridge Island, WA


-----Original Message-----
From: Eugene Hunn <hunnhome at accessone.com>
To: tweeters at u.washington.edu <tweeters at u.washington.edu>
Date: Tuesday, October 28, 1997 8:47 PM
Subject: Re: Thayer's Gull Question


>Gene Hunn, Seattle, hunnhome at accessone.com
>
>My id routine is roughly as follows, assuming, of course, an adult:
>
>Pink legs? Yes. That rules out California, Ring-billed, Mew, etc., not to
>mention Lesser Black-backed.
>
>Mantle as pale or paler than all the hulking Glaucous-wings, Westerns, and
>their hybrid spawn? Yes. Also rules out Slaty-backed, etc. Go on.
>
>Wing with sharply contrasting black tips? Yes. Rules out Glaucous-wings and
>Glaucous-winged X Western hybrids (the latter mostly have dark gray wing
>tips, and not so sharply contrasting) again plus Iceland including
Kumlien's
>Iceland Gull, with wing tips of some shade of gray.
>
>Eye not glaring pale yellow? Yes (that is, no, it's not glaring pale
>yellow). Rules out Herring. The iris may vary from pale brown to rich
yellow.
>
>Head more round and bill less heavy than the other pink-footed gulls? Yes.
>Rules out Herring, etc. again. Now you're beginning to feel confident about
it.
>
>Finally, check to see if the black on the wing tip is limited, that is,
less
>extensive and more interrupted by white "windows" than is normally the case
>with Herring and Ring-billed Gulls (which have mantles as pale or slightly
>paler than Thayer's) and that from the underside the primaries look pale
>gray, not blackish (as in Herring Gulls). You can see this best in flight
>but it is also noticeable when the bird is standing or sitting as you can
>see the top of the wing and front and the underside of the tip of the wing
>in back, which should appear pale.
>
>If the legs are a deeper pink than the other pink-footed gulls nearby,
fine,
>but I wouldn't rely too heavily on that mark.
>
>Not infrequently, however, I find a bird that otherwise fits Thayer's Gull
>but that has a paler eye, more like a Herring Gull, or that has dark gray
>rather than black on the wing tips, more like a Kumlien's Iceland Gull. In
>such cases I shrug my shoulders. By the way, I saw one like the latter at
>Green Lake last Sunday. It could have been a dark Kumlien's, but hey....
>
>If the bird is a first year bird... [save that for another thread].
>
>Gene Hunn.
>
>At 08:07 AM 10/28/97 -0700, you wrote:
>>Hi Tweeters,
>>
>>I have been over to the Sequim-Dungeness area three times in the last two
>>weeks (wonder why?) and have tentatively ID'd a moderately large number of
>>Thayer's Gulls mixed in with the other gulls (Usually Bonaparte's, Mew,
>>Glaucous-winged, California, and 'Puget- Sound': Glaucous-winged X Western
>>Gulls). For example, at the John Wayne Marina, a Thayer's in a flock of
>>about 40 Gulls, and on the rock wall in the parking lot at the Three Crabs
>>Restaurant, 3 Gulls, one of which was a Thayer's. Features I use to try
>>to ID a winter adult Thayer's: Smaller than the typical Glaucous-winged X
>>Western Gull, with a less imposing bill and 'softer' rounder look to the
>>head, bubble-gum colored legs, more mottled on the head and neck, dark
>>primaries but not extensive like Mew or California, red dot on bill,
>>lighter eye color.
>>
>>Sometimes I will be looking at a group of 60 gulls and can convince myself
>>that 6 of them are probably Thayer's. My question is: am I fooling
>>myself? Are these just a normal variation of hybrids...the details about
>>the 'webbing' on the wing tip usually pointed out in field guides escapes
>>me... Even when I'm birding with much better amateur birders, their
>>reaction when I point one of these gulls out is typically:' Yeah, I can go
>>with that', as if the ID is tentative and 'statistical', rather that
>>positive. But the experts don't seem to have any trouble with the
>>ID...what are they doing?
>>
>>
>>Rick Romea "We might as well be walking on the sun"
>>Seattle, WA - Smashmouth
>>
>>rromea at stioptronics.com
>>206-523-5831 (Home)
>>206-827-0460 X 316 (Work)
>>
>>
>>
>