occidentalis

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Eric Hopton
Posts:11
Joined:Tue Aug 16, 2011 4:59 pm
occidentalis

Post by Eric Hopton » Wed Oct 24, 2012 8:10 pm

I am pretty sure this is a 1st winter Western Gull pictured in San Francisco in March but would appreciate any input please.
5383 Western Gull 1st winter 2.jpg
5383 Western Gull 1st winter 2.jpg (293.59KiB)Viewed 3740 times

adriaens
Posts:229
Joined:Sun Sep 27, 2009 9:24 pm

Re: occidentalis

Post by adriaens » Thu Oct 25, 2012 7:10 pm

I can see the resemblance, but I doubt that this is a pure bird.
The plumage is rather pale overall for a 1st-cycle Western Gull in March. Especially the primaries look paler than usual.
Note also that a few juvenile scapulars have been retained, which is unseasonally late.
My guess would therefore be that this bird shows influence of Glaucous-winged Gull.

Eric Hopton
Posts:11
Joined:Tue Aug 16, 2011 4:59 pm

Re: occidentalis

Post by Eric Hopton » Sat Oct 27, 2012 5:05 pm

Interesting and very helpful thank you. It was the fact that the bird was noticeably more pale than other Westerns present that made me unsure about this one especially as I have very limited experience of this species. Also when trying to firm up IDs of my shots that day using mainly Olsen/Larsson there seemed to be more pale edges to the inner primaries than would be expected on a similarly aged Western. Unfortunately I could not get a shot of another standing young Western for comparison - lots of beautiful adults were very obliging though as were the Mews.
Thanks again.

Eric Hopton
Posts:11
Joined:Tue Aug 16, 2011 4:59 pm

Re: occidentalis

Post by Eric Hopton » Sat Oct 27, 2012 5:08 pm

5384 Western Gull 1st winter 2.jpg
5384 Western Gull 1st winter 2.jpg (268.24KiB)Viewed 3724 times
Another shot of the same bird - a little more head-on.

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