The graylag goose flies 1800 miles...
... from south-western Europe to Scandinavia.
The story of migrating birds is the story of a promise:
The promise to return.
They fly, often thousands of miles, beset with danger...
... for a single reason:
To survive.
Their migration is a fight for life.
When spring comes, they take wing for the Arctic.
Some fly relentlessly, night and day.
Others make the trip in stages...
... laboring to reach their distant destination.
The Eurasian crane flies 2500 miles from Spain to the boreal forest.
The white stork flies 3100 miles from central Africa to Western Europe.
To navigate across the latitudes...
... they use the natural beacons of the universe:
The sun, the stars.
They can track the earth's magnetic field...
... as sensitively as a compass needle.
The barnacle goose flies 1500 miles from western Europe to Greenland.
All over the Northern Hemisphere...
The whooper swan flies 1800 miles from the Far East to the Siberian tundra.
... on every continent the spring migration has begun.
No barriers stop them.
The birds make straight for the far north.
The bar-headed goose flies 1500 miles from lndia to the central Asia steppes.
The red-crowned crane flies 600 miles from the Far East to the Siberian taiga.
The bald eagle flies 1800 miles from the American West to Alaska.
The Canada goose flies 2000 miles...
... from the Gulf of Mexico to the Arctic Circle.
All across America...
... from coast to coast...
... the migrants wing their way towards the Arctic Circle.
The snow goose flies 2500 miles from the Gulf of Mexico to the Arctic lands.
The Clark's grebe in Oregon.
The sandhill crane flies 2000 miles...
... from the Central American plains to the arctic lands.
The greater sage grouse in ldaho.
Coming from every continent...
... the migrant birds converge upon the Arctic and disperse.
Their life as a community is over.
Now, it's family time.
There is a world apart:
The realm of sea birds.
Every spring, they quit the ocean waves...
... and flock to nest on the same cliffs and rocks.
The common murre are scattered over the North Atlantic.
The northern gannet in the North Atlantic.
The Arctic summer is short-lived.
Soon the northern lands will be locked in the cold of the polar night.
lt is time for the fall migration.
No more food. Time to leave.
Flying south is now a matter of life or death.
The Arctic tern flies 12,500 miles from the Arctic to the Antarctic.
Out in the ocean...
... any floating refuge can save the life of an exhausted bird.
For the others, there's no rest until the coast.
ln the fall, there is one prime necessity:
Stay clear of bad weather.
Traveling south through North America.
The red-breasted goose traveling south through eastern Europe.
The fall migration thins the ranks.
Among the survivors, by flying with their elders...
... the youngsters memorize the route and recognize the landmarks...
... they will fly over twice a year, throughout their lives.
Traveling into Africa.
For millions of birds from Europe...
... the journey's end is Africa...
... but many will fall by the wayside.
The waders fly 6200 miles from the Arctic Circle to the west coast of Africa.
At the end of their odyssey...
... birds from all over reach the heavenly tropics.
The African white pelican crossing Africa.
Heaven is ephemeral.
lt will only last a season.
Once again...
... they must take to the skies in their endless search for food.
The Amazon.
The albatross around Antarctica.
No landmass slows the swell of the southern oceans.
Sea birds nest on wind-lashed islands.
The young albatross only comes to land...
... after circling the Antarctic for several years.
The rockhopper penguin travels 620 miles...
... following South Atlantic currents.
The king penguin travels...
... from the southern continents to the Antarctic islands.
A year has passed.
Millions of birds have flown thousands of miles.
ln the sky, the same journeys start over again.
ln the Northern Hemisphere...
... migrating birds herald a new spring.
The promise to return has been fulfilled.