Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!hp-sdd!hplabs!oliveb!oliven!mjm
From: mjm@oliven.olivetti.com (Michael Mammoser)
Newsgroups: rec.birds
Subject: Re: Trip to Mass.
Summary: Thayer's Gull
Message-ID: <31830@oliveb.olivetti.com>
Date: 1 Nov 88 22:34:10 GMT
References: <691@picuxa.UUCP>
Sender: news@oliveb.olivetti.com
Lines: 49

In article <691@picuxa.UUCP>, gpasq@picuxa.UUCP (Greg Pasquariello X1190) writes:
 > 
 > But the best bird came as we were headed back to port.  It was
 > with the other gulls, and was very probably a Thayer's gull.  I managed to 
 > see the bird quite well, and it had many of the characteristics of the
 > Thayer's.  Photos were taken, and Wayne Petersen was on board (a very good
 > birder of national renown).  He felt it could be a Thayer's but would not
 > say for sure.  I will let you know what the experts say about the photos.
 > It would be a life bird for me if I could have identified with certainty.
 > Oh well, maybe next time.
 > 
 > If anyone on the Left Coast has any tips for id'ing a Thayers (Mike?) maybe
 > you could send them or post them.  I would be greatful.
 > 

	Two weeks ago I was out at the Bay and found the first Thayer's of the
season; 6 birds in a flock of Western, Herring, and California Gulls.

	Thayer's is intermediate in size and structure between Herring and 
Iceland. The mantle is slightly darker than on Herring and obviously darker
than on Iceland. Compared to Herring, the bill is smaller and the head is
rounder, giving the bird a more "gentle" appearance; although not to the extent
it is on Iceland. Thayer's will have a dark eye, which may be only a brown-
flecked yellow, but never entirely pale like Herring. The legs may be a deep
rose-pink or purplish-pink, where Herring and Iceland have pale pink legs.
The black on the wing-tips is not as extensive as on Herring. The black is
limited to the outer webs of the primaries except at the very tips of the
feathers. When the wings are fully spread, the effect is of black and white
lines on the wing tip (similar to the wing tip pattern for the Kumlieni race
of Iceland Gull, except the Kumlieni has a frosted gray color and not black
like Thayer's). The underwings are pale silvery with dark tips to the primaries.
The overall effect is a pale underwing, and you may notice a series of dark
spots along the trailing edge of the primaries.

	A good identification guide for gulls is; Gulls, a Guide to Identifi-
cation by P. J. Grant. However, make sure that it is the second edition or it
won't include Thayer's or other west coast species.

	I don't have any experience with Iceland Gull or other east coast
gulls (notice that I don't say the right coast; I don't want you guys to get
swelled heads :-) ), but out here I look for a smallish dark-eyed, pink-legged
gull with a slightly darker mantle than on Herring. If it is flying, look for
the striped effect in the dark area of the wingtip, or the pale underwing with
dark spots on the trailing edge of the primaries. Checking the bill size and
head shape is probably something you would want to do at length; probably with
a Herring Gull next to it for comparison.

Good luck,
Mike