[Birdtalk] California Gull vs Ring Billed Gull

[Lofthouse]

Cliff,  thanks for taking the time to comment.   

BTW  those gull pics were taken on March 13, 2007.  They were spring pictures. 

Jim
  ----- Original Message ----- 
  From: Cliff and Lisa Weisse 
  To: Birdtalk 
  Sent: Tuesday, April 08, 2008 7:16 AM
  Subject: Re: [Birdtalk] California Gull vs Ring Billed Gull


  Jim,

  Head streaking of varying extent is seen on gulls during winter but adults have clean white heads during summer.  There are exceptions like Western Gull which has no streaking or a very small amount.  Some Glaucous Gulls have little or no streaking as well but most species develop streaking.  Other changes include duller bare parts color during winter (legs, bill, eye ring) and sometimes some black or blackish on the bill.  They molt all their feathers in summer so the feathers are in their most worn condition now.  If you look at the bottom two photos on your page the California Gull with wings raised has visible wear on the primaries most easily seen on P5-7 (counting back from the outermost feather on the wing these are the 4-6 feathers in from the end of the wing and they have more pointed, notched tips where the feather has worn away from beside the shaft.  Gulls molt some of their body feathers in late winter/early spring in preparation for breeding and that's when they lost the head streaking.  

  Cliff

  Lofthouse wrote: 
    Good stuff Cliff.  Thanks.

    Would you care to comment on the lack of streaking on the nape of the gulls in my pictures?

    Sibley shows that to be pretty obvious on the CAGU.  

    Jim

    PS  I have sent several posts on this subject and none of them have made it back to my inbox.  They must be going though as you have answered.  I wonder where the bottle neck is?
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