Hi Tweets,

Gene Hunn writes, re Thayer's Gull:

(snip)
>the primaries will be neatly margined by whitish buff (and the
>coverts also neatly patterned). In flight the secondaries and tail are
>darker than the body.

These details and those above the snip refer to its Basic 1 (First-winter)
plumage; Basic 2 is a 'ghost' version of the first with the adult's pale
grey back, and when Thayer's in either Basic 1 or 2 gets worn pale flight
feathers by the end of the winter (late Jan--early Apr) each may generate a
few spurious 'Iceland' reports.

When these gull ID threads revive, I wish I had a million bucks to buy a
truckload of Peter Grant's book 'Gulls, a Guide to Identification' and give
one away free to everyone who's ever had a gull ID problem (that's why I'd
need the million bux: who hasn't?). Nothing comes as close to making gull ID
routine (yes, routine) in about 95% of sightings at just about any age of
the bird, not even the National G. It has far and away the most
comprehensive descriptions and great photographs of complete plumage
sequences of all North American and Western Palearctic (Europe, UK, N
Africa) gulls and most of their races at all their ages between down and
adult. It may not give you 100% of the answers--as Gene says, you won't be
able to call them all--but it'll give you one heckuva lot more confidence in
tackling gulls. After a couple of years' worth of using it, any bird which
gives you problems will be one that will give *anyone* problems. It's dated
in an area which touches on us lightly, if at all, so far: the Herring Gull
complex is undergoing much taxonomic revision in Europe and Asia
(sciencespeak for 'it's a real mess'; I've never known a time in twenty-five
years of gull-chasing when sorting out European and Asian Herring Gull races
wasn't the despair of Old World birders and ornithologists. We're *so* lucky
in having only one N American race, smithsonianus. Probably. '-), and any
fallout from it will likely be felt in Alaska where at least one of the
races involved (vegae) shows up regularly.

Specifically, in the Thayer's Gull species account, besides Grant's
description of the juvenile-to-adult Thayer's plumages, he discusses at
length the separation-points from adults and immatures of the North American
race of Herring Gull, the other two 'Iceland' Gulls, and Glaucous-winged,
Western and Western X Glaucous-winged hybrids. His species account on
Thayer's, particularly for the non-adult plumages, mirrors and enlarges on
Paul Lehman's original ID article in Birding from the early 1980's. Most
Cascadian birders learned their Thayer's Gull ID from text, illustration or
photograph in these two sources. As a long-time gull-junkie, I can't
recommend Grant's book too highly as the only place you'll see
highly-detailed *complete* descriptions of these gulls.

>A Kumlien's Iceland Gull should show distinctly
>whitish primaries (but beware of the effects of11 wear late in the winter or
>in early spring) and tend to have an even daintier bill.

It's also possible that the smallest-billed birds are young female Thayer's
or Thayer's/Kumlien's Iceland hybrids (offspring of two species, as Mallard
X Gadwall) or intergrades (offspring of male and female of differing races
within a species, i.e., 'Red-shafted' and 'Yellow-shafted' Northern
Flickers, or 'Myrtle' and 'Audubon's' Yellow-rumped Warblers) depending
whether Thayer's and kumlieni are separate species or races with pale
eastern birds (kumlieni) clinally grading to dark western birds (thayeri)
and many intermediates unidentifiable. The nominate Iceland Gull (L. g.
glaucoides) has little to do with either, as its breeding population in
Greenland is geographically isolated from Thayer's/Kumlieni. I'll reiterate
my experience of looking at an adult gull in a field S of Vancouver BC a few
years ago with Al Jaramillo, who knows as much about gull ID as anyone I've
met. It was a bird any Vancouver BC birder would not have wasted a second
calling it a Definitive Basic Thayer's Gull. Al, who hails from Toronto,
said that if any eastern gull-junkie had seen that same bird on a landfill
in Ontario, he or she would have just as unhesitatingly called it a
Kumlien's Iceland.

>There are still a
>percentage that don't pan out.

It ain't easy when it's hard, that's fershure. Thing to remember is that if
you have the knowledge, gull ID pans out not all but most of the time; *it's
when you don't have the ID tools they're scary*. One thing in our favor is
that unlike warblers and empids, most gulls stand around long enough to be
indentifiable. It could be lots worse: a Thayer's-type gull with the habits
of a Connecticut Warbler. Now *there's* a terrifying thought.

Michael Price We aren't flying...we're falling with style!
Vancouver BC Canada -Buzz Lightyear, Toy Story
mprice at mindlink.net