Thayer's Gull (thayeri)
(last update: January 22, 2013)
Thayer's Gull 1st cycle (2CY), January 22 2012, North Point Marina, Illinois, US. Picture: Amar Ayyash.
Bird in juvenile plumage. Note extensive dark tertial centres and pale crescents on primary tips. Fine uniform dark texture on underparts and in the neck. Black bill. Wide spaced undertail coverts pattern, with regular lines (not messy).
