ML645063873

觀察細節

I believe this is a first-cycle Thayer’s. Larger than nearby Ring-billed Gulls. Dark bill a bit thinner than Herring Gull and thicker than Kumlien’s. Darker primaries with white edging. More evenly and finely patterned coverts and scapulars. Lighter, creamier-colored body overall. More uniformly light-colored underwing through wingtips seen in flight.