In autumn, many bald eagles from northern areas find their way to the Upper Mississippi River Valley, where stretches of the river do not freeze.

Each spring, the eland must climb the sheer cliffs of the Drakensberg to reach the new grass on the plateau. Watch the full episode now.

This video-enhanced lesson uses clips from the NATURE film "Crash: A Tale of Two Species" to explore the interrelationship between the horseshoe crab and a small migratory bird called the red knot. (Grades 5-8)

These video clips from the NATURE episode, "Crash: A Tale of Two Species" explore the interrelationship between the red knot and the horseshoe crab.

Seasonal changes impel a wide variety of creatures to begin their epic migrations. Watch the full episode now.

Following their parents' lead, the flamingo chicks march across the barren desert for weeks.

It's October in the Upper Mississippi Valley, and the weather is mild. Plucking coots and mallards from the water, the bald eagles show off their aerial antics.

This video-enhanced lesson will challenge students to design and conduct scientifically valid experiments to evaluate hypotheses regarding an animal’s expected behavior in response to changes in its environment. (Grades 9-12)

The segments from the NATURE episode "Extraordinary Birds" show examples of the adaptations of different birds to their varying environments.

Video segments from the NATURE film "Earth Navigators" feature cycles of animal migration from one part of the earth to another, including butterflies and wildebeest.