Three Snow Geese at Des Moines Marina Park yesterday. One white phase
adult, two blue phase adults. The blue phase birds both had black from
the nape of the neck (back) to the top of the head; and black bills. I
was assuming that a range of immature-adult variations occur. It this
true?

Thanks

Jane Stewart
Research Center
Foster Pepper & Shefelman PLLC
(206) 447-6474
f(206) 447-9700
1111 Third Avenue, 3400
Seattle, WA 98101-3299

>----------
>From: mprice at mindlink.bc.ca[SMTP:mprice at mindlink.bc.ca]
>Sent: Wednesday, November 05, 1997 11:33PM
>To: tweeters at u.washington.edu
>Subject: Re: Starting Gull ID
>
>Hi Tweets,
>
>Bob Norton writes:
>
>>In starting to identify gulls ignore any but those adult gulls that are
>>close and perched or standing nearby.
>
>Good idea at the beginning of your gull-ID career.
>
>> Large pink legged gulls: (see below for the smaller ones). In our area
>>98% are in the WESTERN, GLAUCOUS-WINGED complex. They have a tremendous bill
>>with a bulbous tip (the end of the bill looks bigger than the base. Try not
>>to to worry about plumage details. [If they have gray wing tips they are
>>GLAUCOUS-WINGED and if they have very dark mantles (backs) and (at this
>>time
>>of the year) a snow white head, they are WESTERNS. The rest are bastards (or
>>intergrades or Olympic or Cascadias or Columbias - all polite synomyns for
>>bastards). Close inspection reveals about 90% of the complex are Olympics on
>>the North Olympic Peninsula.]
>
>This could be a little confusing. Though the birds in this complex are
>usually large, particularly the males, their 'tremendous' bills are
>relatively short and comparatively can be quite deep with the expanded tip
>that Bob mentions, and the degree of downcurve or 'hook' quite pronounced
>when compared to the other white-headed gulls. The color can range from a
>slightly green-tinged yellow (most Glaucous-winged) to a warmer yellow on
>most Westerns to a rich bright orange-yellow on some Western and hybrid
>individuals.
>
>As far as forgetting about plumage details, I'd agree that fine-point detail
>would be a premature challenge to someone unfamiliar with gull ID, but a
>total eschewal may be counter-productive in many instances with these two
>species and their hybrids.
>
>At this time of year, when these birds are in Basic plumage, most Westerns
>have either pure white heads or just a bit of cold brownish-grey head
>streaking whereas Glaucous-winged Gulls can have some to much cold grey
>streaking and barring on head, throat and upper chest, sometimes so
>extensive as to give a heavily 'hooded' look.
>
>A classic adult Western in winter will have a pure to barely-streaked white
>head, a *dark* grey mantle, conspicuous white secondary and tertial
>crescents (on the open wing, these form the white trailing edge to the
>wing), black primaries on the folded wing with small white tips on both
>upper- *and* underside, white underparts, and dull pink to dull purple-pink
>legs.
>
>A classic Glaucous-winged in winter has variable amounts of 'hooding', a
>pale grey mantle and pale grey primaries on the folded wing that are the
>roughly the same hue of grey as the mantle or slightly darker.
>
>Hybrid plumages run in a continuum from dark as one parent to light as the
>other. At one end it's possible to see a white-headed and dark-mantled gull
>with black wingtips open the wing to preen only to show that the underside
>is pale grey: allowing for light conditions, this indicates a hybrid.
>Likewise, a bird as pale-mantled and as heavily hooded as any
>Glaucous-winged might have very dark grey to black primaries. And everything
>in between.
>
>> One sentence capsules of the pink legged other reasonable possibilities:
>> Runts: THAYERS (see Gene Hunn's excellent rundowns on this species which
>>appeared on TWEETERS earlier in the week and save it in case you carry gull
>>study to a higher level. It is the best capsule I have seen.)
>> Light eye, not as heavy a bill, a lighter mantle and a somewhat smaller
>>bird (than the WESTERNXGAUCOUS-WINGED complex): HERRING. But beware of
>>calling this as there are a lot more light eyed bastards and THAYERS than
>>HERRINGS around, HERRING is uncommon here on the Olympic Peninsula, at
>>least.
>
>Well, 'runts' may be an unfortunate choice of words here. Herring is usually
>as large as Glaucous-winged and Western, Thayer's not much smaller, and both
>larger than California Gull, a medium-sized gull. Consider also that there's
>sometimes overlap between large males and small females of different species.
>
>In addition, often the most noticeable mark of adult Thayer's is the
>rose-pink to magenta-pink legs. Thayer's/Herring separation is something
>beginners might want to put off for a little while, as there's a pretty wide
>range of fine-point characteristics to look at. But that's a judgement call:
>if ready, go for it.
>
>>Large and all white with a bicolored bill (dark on the end, light at the
>>base with a SHARP division between colors): GLAUCOUS GULL. These are not
>>adults, the adults are uncommon here. They frequently have attractive fawn
>>or
>>brownish feather edging..
>
>The 'all-white' plumage is usually only the second-year birds at the
>beginning of the winter, with the first-year birds sometimes quite brown;
>they both wear to overall white by the end of each winter, and they have
>pale unmarked primaries at any age. And some common gull species have this
>sharply-bicolored bill pattern as juveniles; its presence alone doesn't ID a
>bird as Glaucous.
>
>> We have three small gulls with pink or red legs and a winter black spot
>>behind the eye. The size difference compared to the Olympics is as of that
>>between tug boats and freighters. Only BONAPARTES is common.
>
>Don't most Bonaparte's Gulls clear the area in winter?
>
>> Smaller gulls with yellow or green legs:
>> Very pale mantle, yellow eye and ring on bill: RING-BILLED.
>> Dark eye, red and black spot on bill and medium size: CALIFORNIA.
>
>In winter, many adult gulls of the white-headed types get a small dark
>shadow beside the red target-spot on the bill making the bill appear to be
>like that of California Gull. Also some subadult gulls will show a similar
>pattern of red gonydeal spot with a dusky outline as an age-related feature.
>By itself, I wouldn't use this mark to ID a gull.
>
>> Dainty with thin all yellow bill: MEW.
>> Small gulls with black legs (uncommon on the westside or viewed from
>>land):
>> Smudgey partial hood: FRANKLINS.
>
>> Poorly defined spot behind eye: BLACK-LEGGED KITTIWAKE.
>
>Likewise.
>
>>THE ABOVE IS DELIBERATELY VERY SIMPLIFIED .
>
>The difficulty with oversimplification, though, is that it leads to
>beginners trying to ID a bird from one field mark alone, a practice leading
>to a) bad ID habits, b) many mis-ID's and c) people giving up when they
>don't need to if they're prepared to adopt a more holistic approach to
>plumage and bare-part features. One feature in isolation is usually of
>little to no use and frequently misleading.
>
>> When you are sure of an adult you can use it as a starting point. E.g.
>>MEW GULL. Are there young birds in the flock. What do they look like. What
>>does the adult look like in flight etc, etc.
>
>A very useful sequence of techniques. I'd suggest instead of Mew--most of
>our wintering Mew Gulls are adult; the immies are usually quite scarce--that
>Glaucous-winged/Western or Ring-billed be used, as they're around all year
>and usually present in numbers.
>
>>In scanning flocks for unusual gulls
>
>If you're a beginner, puh-*leeze* don't start looking for the unusual before
>you pretty well know the usual. Yeah, I know: there's more juice and people
>get more excited and your status rises, but trust me, it's too early. I
>think it was the writer, Pete Dunne who once wrote satirically of
>rarity-hunting before one's ready, "When I was young, I had no trouble
>finding rarities. I'd just look at a plate that had some rare bird on it,
>and the next day, there it was." I think most of us have gone through this
>phase, not knowing any better. Well, now we do. When you have solid
>experience and knowledge of the birds that are usually there, the rare ones
>will usually be perceptibly different. Unless you're a prodigy, don't try to
>play Mozart and Chopin before you've had a hack at 'Chopsticks'.
>
>(snip)
>>Most gulls can be figured out and you can go as deep into the subject as
>>you wish but we all should be able to identify typical adults. If you don't
>>want an intellectual challenge, watch Monday Night Football.
>
>Well, I'd leave a little space in there for doing it for enjoyment, as well.
>And I have a little trouble with that word 'should': I can just see this
>really sadistic high-school teacher I had looming up in front of our class,
>saying, "You *should* be able to tell the difference between these algebraic
>formulae, hmmm?" on the second day of the course. And also not feeling
>stupid because you may not pick it up right away. It actually has little to
>do with intellect and everything to do with becoming familiar with regular
>patterns in plumage and size. There's nothing intrinsically easy or simple
>about gull ID and it takes most people a comparatively long time to become
>familiar with what is a pretty complex family in a part of the world where
>the ubiquitous presence of hybrids between the two common large coastal
>gulls renders recognition-patterns even more complicated. Not to say it
>can't be done, but it sure won't be overnight. And there's nothing stupid
>about watching Monday Night Football. Curling, now there's a case for that.
>'-)
>
>I'd suggest again that you get the best ID material you can (Gulls, by
>Grant; Seabirds, by Harrison), look at as many gulls as you can as often as
>you can. If it gets to be too frustrating, step back from the scope or put
>down your bins and take a few deep, slow breaths, then try again or look at
>something else for a while. Maybe pick an individual gull and write down a
>description to check against the book(s)--*very* useful practice. Give up,
>even, when it stops being fun, and try again another day. Rather than feel
>like you're back in school and awful things will happen to your self-esteem
>because you aren't learning this stuff quickly enough to be an expert--that
>takes years, and learning from many, many mistakes--or to satisfy others'
>preconceptions and agendas of what constitutes a 'good' birder, relax
>instead. Stay in control of the process. After all, you've got the rest of
>your life to learn, and no matter how much you learn, there will *always* be
>more. Be prepared to feel confused as part of the process for as long as it
>takes for that wonderful moment when something clicks and you realise you
>now *know* that bird, and you wonder that there was ever a time you didn't.
>
>Michael Price We aren't flying...we're falling with style!
>Vancouver BC Canada -Buzz Lightyear, Toy Story
>mprice at mindlink.net
>
>