Long description

This figure is a simplified world map on which the migration routes of the artic tern are shown as arrowed lines. The birds travel a relatively short distance from their breeding sites in Greenland and Iceland to an area in the North Atlantic, where they make a fuel stop. Then they head south over the Atlantic, passing close to the northwest coast of Africa, after which the route branches. One branch heads southwest, towards the northeast coast of South America; it follows the coastline, then turns southeastwards to terminate in the wintering grounds of the Antarctic. The other southward migration route follows the west coast of Africa down to the tip of the continent and then turns southwest and on to the Antarctic wintering grounds. There is a single return route, which snakes over the Pacific and Atlantic oceans, heading first north, then northwest up to the northeast of South America, then north again up to the fuel stop in Greenland and Iceland, and finally back to the North Atlantic breeding areas.