its plumage. Its population has since rebounded and it is probably the most common gull in North America. The population was estimated in 2006 as 2.55 million birds. References External links Ring-billed Gull at Université du Québec à Montréal (UQAM)'s Research and banding program Ring-billed gull Species Account – Cornell Lab of Ornithology Ring-billed gull - Larus delawarensis - USGS Patuxent Bird Identification InfoCenter Video - Ring-billed gull at Niagara Falls ring-billed gull Birds of North America Fauna of the San Francisco Bay Area ring-billed gull Taxa named by George Ord