Second winter or adult? Unfortunately I forgot to check the primaries. Note the little bit of the red gape showing. I have heard that you can tell the second winter Ring-Billed Gulls from the adults by how defined the ring on the bill is. Any ideas?
Last edited by Aidan Briggs; 12-27-2009 at 11:53 PM.
Aidan With the bill being yellow and after checking bird of NA on line this is an adult Ring-billed Gull as your second picture the 2nd year gull has a greenish bill
Regards
Myer
Looks pretty good for an adult to me. Soft parts tend to vary on continuous scales rather than discrete states so expect variation. The ring does become crisper as the bird matures but you can use better characters for picking out 2nd winter ringers. The bill color and the duller eye in your 2nd image seem more useful but in a line-up of ring-billed gulls I tend to use leg color; pink in 1st winter, grenish 2nd winter, yellowish >=3rd winter (but again, soft parts do show variabilty).
I agree with above. I have seen the red gape and red orbital ring in adults. I will post some of my photos. adult, 2nd winter and 1st winter in that order. Correct me if I am wrong.
I would caution against using the black in the tail as an absolute aging criteria. I have seen clearly second-cycle Ring-billed Gulls with no black on the tail, and it's rather common to see them with only a couple of black spots as opposed to the whole band. The more consistent marks are the outer primaries, which in mid-winter will be dark brown and lacking the big mirror on p10, and the bill and eye.