Orphaned baby sea turtles in Thailand; performing critical exams on members of one of the rarest turtle species on Earth; teaching rescued turtles to swim again.

Rescued elephants find a second chance at a Thai sanctuary; a vet treats injured elephants; cutting-edge research; a fun encounter with a baby elephant.

Jeff helps to save the Florida Everglades' ecosystem and faces its most important predators: bull sharks, snook and American alligators.

Dolphins off the coast of Florida; manatees in the Caribbean; tuna of New England; penguins of South Africa.

A pregnant beluga whale; a pregnant dolphin; a family of peregrine falcons; a mother octopus.

Jeff travels to the beautiful beaches of central California to visit the massive, mighty elephant seals and witnesses one of the most epic animal migrations on Earth.

Six-gill sharks; sand tiger sharks; bull sharks.

Saving 14-foot tiger sharks in Hawaii; protecting sharks from tourists and tourists from sharks.

Manta rays off the coast of Maui; the largest manta ray at the Georgia Aquarium.

Jeff travels to the coastal mountains of Big Sur, Calif., to help save endangered condors.

The island of Catalina: kelp forests, sea lions, endangered foxes; a nighttime dive.

Fur seal pups; baby bats; timber rattlesnakes; a humpback whale calf.

Habitat loss, climate change and pollution threaten animal species around the world; Australian bull sharks; a Puerto Rican parrot; rare turtles.

From the shoreline of Cape Town to the inland delta of Botswana; African penguins; a hidden lagoon of massive hippos; a deadly spitting cobra.

Puffins use their wings to fly underwater; nursing an injured bald eagle; saving albatross from predators; little blue penguins build their nests on ocean cliffs.

Face to face with a two-spot octopus; communication of humpback whales; health assessment of a Southern sea otter.

Capturing timber rattlesnakes for research; breeding programs to increase snake numbers in the wild; snake surgery; the next generation of rattlesnakes enters the world.

Alligators in Florida; crocodiles in the Okavango River; sea snakes in Queensland; tuatara in New Zealand; reptilian surprises in Botswana.

The Australian Zoo and Veterinary Hospital founded by Steve Irwin and his family; a sick koala; returning a sea turtle to the wild.

Saving the magnificent whales of the Hawaiian Islands; melon-headed whales; pygmy whales; pilot whales.

Marsupials; threats to Tasmania's habitats; conservationists fight to save the unique animals found nowhere else on Earth.

The planet and its wildlife.

Dazzling, state-of-the-art high-definition imagery highlights this breathtaking documentary series featuring footage of some of the world's most awe-inspiring natural wonders -- from the oceans to the deserts to the polar ice caps. Actress Sigourney Weaver narrates this American version of the original BBC production.