Three osprey chicks embark on their first migration from Martha's Vineyard, Mass., to South America.
A herd of 120,000 caribou travels across the Yukon territory to calving ground in Alaska.
Gray whales dodge fishing nets and white sharks on their 12,000-mile migration.
Steve camps out with three wild dogs who leave their pack to start packs of their own.
Following bar-headed geese from Tibet to Nepal.
When an elderly polar bear comes out of hibernation, she must do everything she can to find food and protect her cub.
Arizona diamondbacks leave hibernation to hunt in the Sonora Desert.
A baby gray whale's 11,000-mile migration from the tropics to the Arctic.
Monarch butterflies migrate from Mexico to Canada.
An eel migrates upon hatching.
Swallows travel from Southern England to South Africa.
A caribou calf migrates from northern Quebec to the coast of Labrador.
An eel migrates upon hatching; gray whales swim from Mexico up the Pacific Coast.
Monarch butterflies migrate from Mexico to Canada; swallows travel from Southern England to South Africa.
Canadian caribou travel thousands of miles annually; Arizona diamondbacks leave hibernation to hunt in the Sonora Desert.