This documentary follows several species of migratory birds over a four year filming period. These birds travel several hundreds if not thousands of miles toward the equator in the autumn, and make the return journey to their higher latitude summer homes in the spring, always taking the same route, using the natural compasses of the universe, the stars, to find their way. Some species, like the arctic tern, even fly from pole to pole. These long and often torturous treks are a matter of survival, to live in a hospitable climate and find sources of food. With the exception of migratory penguins, travel over oceans is especially difficult as the birds have little refuge unless there is something floating on the water, such as a ship, on which to land. Otherwise they must continue flying until they reach land. Some will not survive the migration due to predators, including man, illness or injury. Although the migrations themselves are done as a community, once the birds reach their respective summer and winter homes, they disperse into family units. And every continent is affected by the migration as every continent is home, at least part of year, to a species of migratory bird.