The Black Tern's 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.
North American Black terns migrate to the coasts of northern South America, some to the open ocean. Those in Europe winter in Africa.
The North American population has declined in recent times due to loss of habitat.