Larus spuh. ID help CCSP today

[Ben S]

Hi all-

Birded the west shades and marina of CCSP today. Got a continueing Pacific Loon (swimming off near Pelican point), as well as a late pelican and two Thayer's (Iceland) Gulls.

I also got this confusing gull. The wingtips have extensive unbroken black on them. The mantle (slightly darker than Ring-billed mantle) and black wing tips have very little white in between. The winter brownish-dinginess the head forms a bit of a collar on the nape, and the bill is pale bill a black tip. The bird in question is in the very center of the three pictures.

Ben Sampson

 Centennial, CO