[obol] John Rakestraw's gull

[Darrel Faxon]

OBOL,
    Another point which I think no one has yet made is that the color of the primaries on the underwing of Western Gull is black; on Slaty-backed paler gray.  Both P.J. Grant's photos and the drawings in the Geographic guide show this.  However, the illustrations in Sibley do not make much of a distinction between the two, which leads me to a question.  Does the southern race of Western Gull, L.o. wyman1 show less black (or lighter black or grayish) on the underside of the primaries than is shown on the northern race?  The adults shown in flight in Sibley appear to be of the northern race, but the color of the underwing doesn't seem to agree with Grant or the Geographic guide, and it doesn't seem to match what I have personally observed in birds I consider to be "pure" Westerns either.  The text in Grant also indicates that there is a difference between the two species in tone and amount of black on the underwing primary feathers.  If we are looking at multiple features to determine the distinction between the two species it seems this feature should be taken into account as well.

Darrel 
  ----- Original Message ----- 
  From: DJ Lauten and KACastelein 
  To: Paul T. Sullivan 
  Cc: obol 
  Sent: Friday, March 02, 2007 9:06 AM
  Subject: Re: [obol] John Rakestraw's gull


  Seriously folks there is a 3rd year SLATY-BACKED BULL just across the border into Cal from Brookings.  It is at the Alexandria Dairy farm on the Smith River in Del Norte Cty, found by Alan Barron a couple of days ago.  You can find pictures of it at http://fog.ccsf.cc.ca.us/~jmorlan/gallery.htm.  Take a look and you'll see the difference.  

  Cheers
  Dave Lauten

  Paul T. Sullivan wrote:

OK,

I know that we will be hearing from some more gull-experts.  There will be 
long text messages discussing (very ably) the Identification points of this 
single bird.  We'll have to wait a week for this to play out, with everyone 
having a say.

Let me suggest a different path:
1. I usually do not open both OBOL and photo webpages at the same time.  If 
I see a link on OBOL and click on it, I'm taken to the photo on the webpage 
and my OBOL screen goes away.  Yes, I know how to get them both open at the 
same time, but a) it takes a long time at home, and b) I shouldn't be doing 
it at work where the computers are faster.

2. Long text discussions with people offering conflicting points of view are 
confusing to my non-gull-enthusiast mind, especially when I don't have the 
photo in front of me, don't know what Vega means, don't know what to expect 
from a 3rd-year hybrid _____________ X ____________ gull in worn winter 
plumage, etc, etc.  These discussions don't really teach me much.

3. So why doesn't someone put up photos of a real Slaty-backed Gull in a 
couple relevant poses -- with arrows pointing to the relevant points of 
identification -- and put up comparison photos of whatever-you-think this 
bird is (Western? Hybrid  ______________ X ______________?) -- again with 
arrows pointing to the relevant points of identification.  Please label the 
photos.  Please be sure that the photo shows the points that are discussed 
in the accompanying text.  Maybe this could be published in Oregon Birds, so 
we don't have to carry our desktops into the field with us.

I agree that this is an opportunity for education, like Greg suggests.  I 
agree that Greg, Dave Bailey, and others are very knowledgeable on the 
subject.  This message is just a suggestion on how you can communicate that 
knowledge to me and others more effectively.

Thanks to you all.

Paul T. Sullivan 

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