Thayer's Gull (thayeri)
(last update: January 22, 2013)
Thayer's Gull 1st cycle (2CY), January 25 2011, Petaluma, CA. US. Picture: Peter Adriaens.
Note pale crescents on primary tips. Fine uniform dark texture on underparts and in the neck. Black bill. Dense pattern on undertail coverts.
