Larus glaucescens nests on rocky cliffs among the seabird colonies of the coastal northern Pacific, from Alaska and the Aleutians south to northern Washington state. Physical Characteristics Adults of L. glaucescens have a body length of 24-27 inches, and a wingspan of around 54 inches, males larger than females.
Wings are also pale grey, with small white patches.
Large, heavy yellow bill with red spot. Skin around eyes purplish pink, iris silver to yellow powdered with brown, giving a dark appearance. During periods of lowest tidal heights mussels and barnacles comprise much of their diet, but at other times sea urchins, chitons, and limpets are preferentially gathered. Barnacles, sea urchins, molluscs, and other resistant food items are gathered from the shore and dropped onto rocks from the air to crack them open. In the vicinity of humans L. glaucescens will scavenge garbage from docks, dumps, and shores, and follow fishing vessels.