A 1987 program examining the work of Maurice and Katia Krafft, who studied and filmed volcanoes around the world before their deaths in a 1991 volcanic explosion. Scenes include a lake of molten lava in Central Africa; an eruption in Iceland; an evacuated school being devoured by Mount Etna.

As the ice shrinks in the Arctic, polar bears are struggling to survive in a fast melting world. Although classified a marine mammal, the polar bear is not adapted to hunting in the water. And it is certainly no match for the world's greatest aquatic hunter -- the killer whale. In the last few years, scientists have noted an ever-growing number of killer whales in Arctic waters in the summer months. More and more have been attracted to these hunting grounds by the growing expanse of open water. They attack the same prey as the polar bears: seals, narwhal, belugas and bowhead whales.

An examination of the extinction threat faced by frogs, which have hopped on Earth for some 250 million years and are a crucial cog in the ecosystem. Scientists believe they've pinpointed a cause for the loss of many of the amphibians: the chytrid fungus, which flourishes in high altitudes. Unfortunately, they don't know how to combat it. Included: an isolated forest in Panama that has yet to be touched by the fungus, thus enabling frogs to live and thrive as they have for eons.

From PBS and NATURE - From the wilds of Costa Rica to the suburbs of our own country, parrot owners, rescuers, breeders, and biologists involved in conservation programs share their stories and the stories of their parrots in this bittersweet and unforgettable film about the difficulties and consequences of keeping and caring for parrots as pets.

A look at the extraordinary abilities of squirrels, from the brainy fox squirrel to the acrobatic gray squirrel to the problem-solving ground squirrel.

Florida is home to beaches, coral reefs, pine forests and the famous Everglades wetland, but a growing human population and abandoned exotic pets like pythons are threatening this wild paradise. Can Florida’s ecosystems continue to weather the storm?

Each year, far from human eyes, a remote expanse of Botswana's Makgadikgadi salt pans hosts one of Africa's last great spectacles when thousands of striped nomads wander the breathtakingly beautiful but barren landscape. It is only by the grace of isolated summer rains that the zebras can survive here at all. Family groups gather together to follow the rains, driven by a constant search for better grazing on islands of grass that dot the pans. Meerkat families watch the zebras come and go, and families of lions wait for them along their grueling trek, hoping for a chance to bring one down. Their journey is one that is sometimes limited by the fragility of new life, but always made possible by the strong family ties that help animals survive in one of Africa's most surreal landscapes. It's a tale of loyalty and sacrifice, of home and exile, of death and new life, in southern Africa's largest zebra population.

In the animal world, as in our own, looks aren’t everything. In fact, some of the most aesthetically challenged creatures — from warthogs and proboscis monkeys to bull elephant seals — are also the most fascinating. A stunning variety of these ghastly yet glorious forms are explored in NATURE’s The Beauty of Ugly.

River of No Return Wilderness is the largest contiguous wilderness area in the lower 48 States. Endless rugged mountains, wild rivers, forests and deep canyons define this land, home to numerous species of wildlife, including wolves, who have just returned after 50 years of near absence. A young couple, Isaac and Bjornen Babcock, chose this wilderness for their year long honeymoon. But what begins as a romantic adventure becomes something much greater for the couple, and a tale of hope and celebration for every life trying to make it in the unforgiving heart of the wilderness.

The Australian pelican is built for long distance travel. One of the largest pelicans in the pelican family, with a light skeleton and a wingspan of over eight feet, it can be airborne all day and deep into the night, riding far and high on rising thermals. When rare weather systems bring heavy rains, huge numbers of Australian pelicans abandon the sea and coastal waters and embark on a mass pilgrimage to a place a thousand miles inland. It’s the last place you would look for one of their kind, the Australian Outback, one of the driest, hottest places on the planet.