Now we know why birds migrate, the next question is how far do they actually fly to find better conditions. The champions among birds that migrate are the arctic terns.
This amazing bird will travel as many as 35.4 km (22,000 mi ) during the course of a year, going back and forth. It nests over a wide range from the arctic circle to as far south as Massachusetts. It will take this bird about twenty weeks to make its trip down to the Antarctic region and it averages about 1.6 km (1,000 mi) a week.
Most land birds only make short journeys during their migrations. But there is one bird, the American Golden Plover, that makes a long nonstop flight over the open ocean. It may fly from Nova Scotia directly to South America, a distance of about 3.8 km (2,400 mi), without even stopping.
We are not certain that birds start and end their migrations on exactly the same day each year. But there is one bird who comes pretty close to it. It is said that the famous swallows of Capistrano, California, are thought to leave on October 23 and return on March 19, but of course, their date of departure and arrival has been found to vary from year to year.