This gull was photographed on December 27, 2006 in the Coastal Plain near Houston and Galveston, Texas; NOTE due to very muddy conditions, bare parts colors are unreliable (most birds had mud-caked bills):
This gull is a LBBG/heuglini/YLGU type:
Note the very pale ground color to the 2nd-generation mantle and scapular feathers, such that they appear paler than the rest of the upperparts on the flying bird - even though the first-generation wing coverts have extensive white fringes that creat a frosted look; the extensive white barring in the greater secondary coverts (such that on the open wing these coverts are more similar in tone to the upper coverts than they are to the dark secondaries - contra LBBG); the extensive wear/fading on the tertials and humerals - with the two lowest terials having been replaced; although hard to assess well, the underparts seem to be whiter than typical for LBBG; the tail pattern:- white-tipped with black tail band tapering on outer two feathers, extensive unmarked white basally on Rs6; the sparse diamond-shaped dark spots on the longest uppertail coverts are "separated" from the sparse dark marks of the rump area by a "U" shaped band that is almost without dark marks (a classic feature of YLGU; how often in LBBG?); the suggestion that the underwing coverts are not the uniform dark of LBBG; the inner 5 - 6 primaries with clearly paler inner webs:
