Figure 1.

Distribution and migration routes for the Arctic Tern (Sterna paradisaea). An example of inter-hemispheric travel of wild birds. The trip from the breeding ground in the high Arctic to wintering areas at the southern tip of South America and Antarctica covers up to 17,000 km and takes several months to complete. Other species of ducks and gulls regularly migrate along transatlantic route breeding sites in the Old World to wintering areas along the eastern coast of North America.

Map courtesy of the U.S. Department of the Interior and the U.S. Fish and Wildlife Service, Migration of Birds, Circular 16 (Washington, D.C., 1998).