One has no idea how abundant the Franklin’s Gull is until one visits the Pacific Coast of South America during the migration of this species. During mid to late November along the coast of Chile and Peru this species is constantly in view, moving south in small to large flocks, thousands upon thousands of them. Then during the middle of Boreal winter, major wintering concentrations in estuaries of Chile reach are in the thousands. It is curious that this gull which is considered an interior species in North America, where it breeds in the Prairies and plains of the center of the continent, becomes so marine during the non-breeding season. Apart from this curious ecological shift during the seasons, this is also the most migratory of the gulls along with the Sabine’s Gull (Xema sabini) which also heads as far south as Chile. Perhaps due to the long migrations of this species, the Franklin’s Gull is also a species which can occur nearly anywhere in the world as a vagrant. Franklin’s Gulls are three year gulls, which means they have two stages of immaturity in addition to the adult plumage. What is highly unusual about the Franklin’s Gull, and almost certainly an adaptation to the long migration, is that it has a two complete molts during the year. One molt occurs before the southbound migration, and the other before the northbound migration.