Although ring-billed gulls (Larus delawarensis) are found across much of North America, they did not occur where I was raised in Western Pennsylvania. Thus as a child I assumed gulls were only found along the coasts. It was indeed a surprise when for the first time I saw hundreds of gulls in an irrigated, inland field.
Ring-billed gulls are thoroughly adapted to civilization. Usually associated with water, fresh and saline, these sociable gulls can be found in rural, suburban and urban environments – including lakes, bays, coasts, garbage dumps, malls, plowed fields – anywhere food scraps are available. They summer into Northern Canada and winter along the coasts and the Southern States into Middle Mexico.
Ring-billed gulls are three-cycle gulls, meaning that it takes three years to attain adult plumage. Breeding adults have pale grey upper parts and are white below with white heads. The wing tips are black, spotted with white along the edges and extend beyond the square-tipped tail when perched. The fairly short bill and the legs are yellow. There is a subterminal black ring on the bill. The eyes are pale. Non-breeding adults have some greyish brown spotting on the head and juveniles have brownish plumage that varies with age.
The diet of ring-billed gulls is determined by what is available. Insects, fish, earthworms, grain, rodents and refuse of every type are consumed by ring-billed gulls. These gulls will forage while walking, wading, swimming or flying and will even steal food from other birds.
Adult ring-billed gulls “play” by dropping objects then swooping to catch them. This might help improve their hunting skills.
These ring-billed gulls were photographed in a flood-irrigated field along Modoc County Road 87 near Lookout CA.