black). Distribution and habitat Their breeding habitat is freshwater marshes across most of Canada, the northern United States and much of Europe and western Asia. They usually nest either on floating material in a marsh or on the ground very close to water, laying 2–4 eggs. In England the black tern was abundant in the eastern Fens, especially in Lincolnshire and Cambridgeshire, until the early nineteenth century. The English naturalist Thomas Pennant in 1769 referred to "vast flocks" of black terns "whose calls are almost deafening." Extensive drainage of its breeding grounds wiped out the English population by about 1840. Intermittent attempts by the black tern to recolonise England have proved unsuccessful, with only a handful of English breeding records, and one in Ireland, in the second half of the twentieth century. North American black terns migrate to the coasts of northern South America, some to the open ocean. Old World birds winter in Africa. Unlike the "white" Sterna terns, these birds do not dive for fish, but forage on the wing picking up items at or near the water's surface or catching insects in flight. They mainly eat insects and fish as well as amphibians. Vagrancy The American race has occurred as a vagrant in Britain and in Ireland. Conservation The North American population has declined in recent times due to loss of habitat. The black tern is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies. Gallery References External links Black Tern - Chlidonias niger - USGS Patuxent Bird Identification InfoCenter Black Tern Species Account - Cornell Lab of Ornithology Black Tern Species text in The Atlas of Southern African Birds black tern Holarctic birds Birds of Africa black tern black tern