This small gull is abundant in coastal Texas, but is seldom found inland. These are non-breeding birds with a smudge on the head instead of the black hood found in the breeding season. The bird on the right is a full adult with white spots on the tips of the primaries. The left bird is a 2nd cycle bird (Basic II in technical terms). Notice the gray smudging on the sides of the breast and flanks on that bird as well as the lack of white tips to the primaries. Olympus D-550z / Nikon FieldScope 3 / 30XWA (hand-held - no adapter).