(Airs Sunday, August 8) Most big cats do their best to remain hidden from human eyes, but none are quite as adept at this as the snow leopard.

Ironically, the powerful, dedicated canines profiled in Sled Dogs: An Alaskan Epic are little more than mutts. They are mixed-breed huskies that have endurance.

For nearly 40 years an albino gorilla named Snowflake was adored by people around the world.

From the Caribbean, the documentary hopscotches to various points on the globe to show viewers a diverse array of animals that make music.

According to legend, Spanish explorers believed that a fountain of eternal youth bubbled up to the surface somewhere in the place we know today as Florida. In a poetic way, they were right.

(Airs Sunday, August 29) Marine biologist Rick Rosenthal set out to capture on film the biggest, fastest, most dangerous gamefish in the sea -- the ancient creatures known as billfish.

Conservationist Rom Whitaker searches for the last of the supersize crocodiles among the titans of the croc world: Nile crocodiles, saltwater crocodiles, and gharials.

TOOTHWALKERS presents extremely rare under-the-ice footage that reveals a complex and potentially dangerous side to this huge and often mysterious mammal.

Hunted almost to extinction over the past three centuries, cougars are making a comeback today, with some 30,000 living in the wilds of North and South America.

NATURE's six-part series TRIUMPH OF LIFE presents the remarkable story of evolution and its survivors.