Gulls, Terns

Thayer’s Gull, Larus thayeri

Family Laridae (Gulls, Terns)

Size: 23"

Season: Winter

Habitat: Coastal areas, harbors, fields; inland along watercourses

Once considered a subspecies of the herring gull and now considered most closely related to darker versions of the Iceland gull, the Thayer’s gull can be difficult to distinguish in the field. It is a large, stocky gull with pink feet, a yellow bill with a red spot near the tip of the lower mandible, and dark eyes (some individuals will show light-yellow eyes). Its plumage is a fairly pale slate gray above, white below, with black markings on the outer primaries. While wintering, the head and neck are streaked brownish. Subadult gulls are variously mottled in browns and grays, with all-dark or dark-tipped bills. Thayer’s gulls, which pick food from the ground or water, have a highly varied diet. The adult is illustrated.