The blue whale, the largest creature that has ever existed, subsists by eating one of the smallest - krill. Attenborough investigates a computer-animated blue whale skeleton to illustrate its immense size and body functions, then catches a glimpse of the elusive creature in the open ocean.
Attenborough explains the functions of fungi and parasites in the jungle. The "corpse flower," which weighs up to 10 kg in some species, is the only visible part of the parasitic plant Rafflesia, and can reach up to 100 cm in diameter.
The male Arctic Hooded Seal has a bizzare way of intimidating rivals and impressing females; he inflates a nasal membrane to make his head appear twice its regular size.
Off the south coast of the United States, dolphins have developed a specialized and daring hunting technique, which requires teamwork, communication, planning ahead, and synchronization. The method the dolphins use to force fish onto the shore is another testament to their high intelligence.
An expert at natural competition, the Giant Amazon Lily ensures its continued existence using a host of survival techniques. This clip includes a mesmerizing time lapse of the plant growing, although it is scarcely needed, as it grows at one square inch per minute.
Like their sea lion relatives, seals evolved from a weasel- or bear-like ancestor, but have become even better adapted to marine living. Antarctic seals rear their pups on the ice where there are no predators, but Arctic seals must watch out for foxes and polar bears.
The Whip Scorpion comes across as even creepier when accompanied by 70's-style science fiction movie music while it stalks and devours this grasshopper.
First off the Pacific Coast of North America, then on a small island in New Zealand, Attenborough describes how sea lions have become even further adapted to life in the water; their breeding and infant-rearing habits. Includes a brief fight between two males over the harem as well as a dramatic depiction of baby's first swim.
Californian sea otters evolved from weasel-like animals, but have developed ingenious methods of finding food, sleeping, mating and keeping warm even in the waters near Alaska.
Mammals have evolved and adapted to live as effectively in water as on land. Humans, however, are centuries behind their aquatic relatives, and therefore, have much yet to learn.
The Desmon, a relative of the shrews, has become adapted to finding food in fresh water by using its "snorkel" or "mini-trunk" not only to help it breathe under water, but also as a sensitive probe.
