This species inhabites coasts, rivers, estuaries, reservoirs and rubbish dumps. It is a highly opportunistic feeder, owing to its varied diet including fish, insects, earthworms, refuse, offal, fiddler crabs, dates, fish eggs, grain, rodents and birds. It lays from late April to May, though this can be delayed in the north of its range due to snow cover. Colonies are often very large and found on low-lying islands in freshwater lakes, on wet meadows and rarely on rivers. Its large, bulky nests are usually built beside rocks, driftwood or vegetation (del Hoyo et al. 1996).

The Ring-billed Gull breeds in the USA and Canada from north California, east Washington and interior British Columbia, across the prairie provinces, north mountains and plain states. Also from the Great Lakes east to the coast. It winters in the southern portion of its breeding range south to the Gulf Coast, Mexico, Central America, Greater and Lesser Antilles (del Hoyo et al. 1996).