Trials of Life

The first episode examines the various methods by which creatures come into the world. Attenborough’s opening statement alludes to the annual spawning of the Christmas Island red crab, of which there are estimated to be some 120 million. The exercise is all the more hazardous since the species is a land crab, and the eggs have to be deposited in the sea - where the most ancient animals on the planet still live and breed. One of the most prolific aquatic egg producers is the giant clam, but some land animals also lay vast quantities, and the mantis is one example. In the Western United States, Attenborough observes a wasp that digs a burrow, conceals it, and stocks it with fresh caterpillars for her emerging young. The grubs of another start life inside caterpillars, and eat the unsuspecting hosts. The problems of larger animals are illustrated by snow geese in the Arctic, which have to defend their eggs from arctic foxes. The process of embryonic growth inside the egg, from laying to hatching, is shown in detail. The malleefowl warms its eggs with rotting leaves, and Attenborough demonstrates the care with which it regulates them by adding sand to its mound - to have it kicked back in his face. The sea louse is a crustacean that commits suicide: its grubs consume so much of the mother’s energies that she dies after birth. Mammals shown giving birth to fully formed young include wildebeest, antelope, sea lions and chinchillas.

This programme describes the ways that various species care for their young. Attenborough defines childhood as achieving two tasks: growing and surviving. He highlights the elephant seal as an animal that experiences a compressed childhood, being abandoned after three weeks and left for up to another eight alone, while it becomes large enough to be able to swim. For terns, there is safety in numbers as the dense population works together to drive out marauding gulls. The snow geese in the Russian arctic show intense devotion as they escort their goslings by foot to the coast some 50 kilometres away. Scorpions carry their young on their backs, while a shrew will leave hers under a stone while she goes to feed. The eider duck is one creature that shares responsibility for its offspring: females regularly supervise the ducklings of others in a group. The mara is another that uses a crèche system, as does the bat, whose nurseries can be up to a million strong. The Florida scrub jay has developed complex parental relationships, using teams rather than pairs. Such behaviour is exhibited on a larger scale by elephants, where all females take an interest in raising a single calf. A chimpanzee’s childhood is socially complicated, as an individual must learn how to behave towards others, as well as master the use of tools. Albatrosses must be accomplished fliers as soon as possible - chicks are shown being hunted by tiger sharks.

The next installment is devoted to the ways in which animals gather their sustenance. Attenborough begins in the South American rainforest, where the proliferation of animal and plant life does not necessarily make it easy to find food. Some leaves are poisonous, and so those that eat them have to be careful. Other plants use food (or nectar) as a bribe to get their pollen transported, and several species of hummingbird have developed exclusive relationships with certain of them. Fruit is also on offer, again as a means of reproduction, and creatures such as squirrel monkeys eat little else. Meanwhile, parrots and macaws take kaolin as an antidote to their diet of toxic seeds. Attenborough witnesses a 60,000 strong flock of knot and dunlin suddenly take advantage of a low tide to feed on tiny mud-dwelling molluscs. Barracuda hunt small fish, and drive shoals of them into bays to be eaten by pelicans, which are besieged by gulls that attempt to steal their catches. One species of gecko is able to differentiate between worker termites and the more dangerous soldiers. The web of the orb spider is hailed as one of the most elegant food catching devices, and the methods of two others, nephila and its kleptoparasite visitor, argyrodes, are explored in detail. Finally, tropicbirds, their crops full with food en route back to their nests, are ambushed in mid-air by a group of frigatebirds, whose aim is to make them surrender their cargo.

This episode looks at those that hunt other creatures and ways of avoiding capture. Attenborough is attacked by a pair of skuas as he approaches their nest, which demonstrates this particular bird's aggressive behaviour, both when taking food and defending its young. Off the shores of Patagonia, the same group of killer whales returns each year to ambush sea lion pups, which stray out of the safer shallow waters. Having grabbed their prey, they take it back out to sea and 'play' with it for some time before killing it. Poison can be used both as a weapon and a deterrent, such as by the viper and tomato frog respectively. Some animals advertise their defensive measures in advance, in case deployment occurs too late. Among them are the skunk, which discharges an appalling smell, and some salamanders that display their toxicity by remaining stationary, with their warning markings visible. Several species of stick insect and their elaborate camouflage are shown. However, none of these methods of protection pose problems to army ants, which can subdue any of their prey, simply by virtue of their size and vast numbers. The Harris hawk is unusual, since it hunts in teams, and a group of six are shown practising their skill in the desert of New Mexico. The final sequence depicts a troop of chimpanzees displaying strategy and co-ordination as it successfully pursues colobus monkeys through a forest in the Ivory Coast.

This programme explores forms of navigation. Attenborough starts in Africa at dusk, by describing some of the species that don't rely on sight. The spotted hyena uses its acute sense of smell to guide it while it hunts nocturnally, while galagos urinate on their hands so they can completely mark their movements. Some animals use echolocation and these include swiftlets, bats and river dolphins. By contrast, electric eels use fields of electricity to sense their environment. During the hours of daylight, other methods are employed: the rufous elephant shrew, with its carefully cleared network of pathways, has a sharp mental picture of its habitat - even knowing the various shortcuts with which to evade capture. Attenborough visits the Sahara to illustrate a species that makes the longest overland journey of any insect: cataglyphis, an ant that uses the sun's position to enable it to return to its nest in a straight line. Lobsters in the Bahamas are shown marching in columns to escape stormy waters. In its search for perpetual daylight in which to fish, the Arctic tern makes a 19,000-kilometre journey from one end of the Earth to the other. The albatross is highlighted as one of the most skilled navigators: it can travel up to 1300 kilometres over sea in search of food for its chicks, and still find its way back to the nest. Finally, Attenborough stands on a waterfall in Ireland to tell of the three-year, 10,000-kilometre journey made by elvers.

This installment deals with how animals construct their shelters from the elements and predators. Burrows and holes can provide considerable refuge, and Attenborough inspects the home of the American prairie dog, an elaborate construction that has its own air conditioning system. Silk is such a valuable commodity that those that can't make it steal it instead. The hermit hummingbird uses it to attach its nest to the underside of a leaf, while the Indian tailorbird stitches two leaves together. However, the expert in complex nest-building is the weaverbird which makes its abode from over 1,000 strips of grass that are perfectly interwoven - and dismantling it if it fails to attract a mate. The beaver is responsible for one of the biggest animal dwellings: its wooden lodge that rises from the river bed stays in place from one generation to the next, and so requires constant maintenance. Some stingless bees use their wax and the resin of tree bark to create labyrinthine structures containing various compartments. Mud is also used by several creatures, such as the potter wasp and the cliff swallow. The termites' intricate creations allow for security, heating, air conditioning, self-contained nurseries and gardens, and sanitation systems. Attenborough hails the species as the consummate home maker, and explores a 15-foot colony in West Africa that contains 1.5 million insects: he crawls right inside to examine its method of ventilation.