Season 27

Video thumbnail: Nature Frogs: The Thin Green Line

Nature

Frogs: The Thin Green Line

It is the greatest mass extinction since the dinosaurs.

Frogs: The Thin Green Line

Video thumbnail: Nature Kilauea: Mountain of Fire

Nature

Kilauea: Mountain of Fire

Kilauea, on Hawaii's Big Island, is the world's most active volcano.

Kilauea: Mountain of Fire

Video thumbnail: Nature The Wolf That Changed AmericaPassport

Nature

The Wolf That Changed America

In 1893, a bounty hunter journeyed to New Mexico on a mission to kill a dangerous outlaw.

The Wolf That Changed America