Which Bird Migrates The Greatest Distance?
The Arctic tern (Sterna paradisaea) migrates the longest distance of any bird. These birds breed in the northernmost reaches of North America, Europe, and Asia. At the end of the northern summer, the Arctic tern leaves the north and travels more than 11,000 miles (17,699 kilometers) to its southern home in Antarctica.
The longest recorded migratory flight of an arctic tern is 14,000 miles (22,526 kilometers). That tern was tagged one July on the Arctic coast of Russia and was recovered the next May near Fremantle, Australia.
Source: Amazing Animals, pp. 86-87.