'Blood Brothers' follows the lives of two species, Paranthropus boisei and Homo habilis who embody two alternative ways of ape-man life. Although heavyset, with distinctive gorilla-like faces, the boisei are gentle characters. They live within a strict social structure and are led by a dominant male whose strength and power holds the group together. The habilis have taken a different approach to survival. They don't have the specialisms of the boisei but instead have developed into the archetypal jack-of-all-trades, inquisitive scavengers prepared to try almost anything to survive. Tough, active, gregarious and noisy, they are always on the move and always alert to the possibility of a meal. But in the near drought of the dry season the habilis are struggling. It seems as if their way of life cannot help them when conditions are tough.

The mission of the film is to underline the crucial ecological role of coral reefs play in maintaining the well being of our planet, and to point out and warn against the dangers that are destroying the world's coral reefs. Entirely filmed using digital technology, thanks to it, the film was shot almost entirely with natural light, thus showing the underwater world as it exactly is. This is the closest you can get to dive without being there. Shot on the Great Barrier Reef in Australia and in the Bahamas, it brings to you the amazing beauty of the many varieties of coral and the immense diversity of the marine life thriving there.

Mammals from tiny shrews, giant anteaters, armoured armadillo to bats have specialised in eating insects. Some have evolved into complex and effective hunters, even pursued their prey into the skies

The magnificent ancient city of pyramids at Caral in Peru is a thousand years older than the earliest known civilisation in the Americas and, at 2,627 BC, is as old as the pyramids of Egypt. Many now believe it is the fabled missing link of archaeology - a 'mother city'. If so, then these extraordinary findings could finally answer one of the great questions of archaeology: why did humans become civilised?" For over a century, archaeologists have been searching for what they call a mother city. Civilisation began in only six areas of the world: Egypt, Mesopotamia, India, China, Peru and Central America. In each of these regions people moved from small family units to build cities of thousands of people. They crossed the historic divide, one of the great moments in human history. Why? To find the answer archaeologists needed to find a mother city - the first stage of city-building. Caral, is so much older than anything else in South America that it is a clear candidate to be the mother city. It also is in pristine condition. Nothing has been built on it at all. Instead laid out before the world is an elaborate complex of pyramids, temples, an amphitheatre and ordinary houses. Scientists developed a number of theories. Some said it was because of the development of trade, others that it was irrigation. Some even today believe it was all because of aliens. Gradually an uneasy consensus emerged. The key force common to all civilisations was warfare. Crucially, there is not the faintest trace of warfare at Caral; no battlements, no weapons, no mutilated bodies. Instead, Ruth's findings suggest it was a gentle society, built on commerce and pleasure. In one of the pyramids they uncovered beautiful flutes made from condor and pelican bones. They have also found evidence of a culture that took drugs and perhaps aphrodisiacs. Most stunning of all, they have found the remains of a baby, lovingly wrapped and buried with a precious necklace made of stone beads.

The first episode looks at how birds first took to the skies in the wake of the insects. It begins in Mexico, where Sir Attenborough observes bats being outmanoeuvred by a red-tailed hawk. Pterosaurs were the birds' forerunners, some 150 million years after dragonflies developed the means of flight, but eventually went extinct together with the dinosaurs. Birds had by then already evolved from early forms like archaeopteryx, the first creature to possess feathers. Its ancestry can be traced through reptiles, and some current species, such as the flying lizard, possibly show paths this evolution may have taken." One of the biggest birds to have ever existed was the terror bird, which proliferated after dinosaurs vanished and stood up to 2.5 metres tall. By comparison, the ostrich, while not closely related, is the largest and heaviest living bird. It was probably the evasion of predators that drove most birds into the air, so their flightless cousins evolved because they had few enemies. Accordingly, such species are more likely to be found on islands, and Sir Attenborough visits New Zealand to observe its great variety, most especially the kiwi. Also depicted is the moa, another huge creature that is now gone. The takahē is extremely rare, and high in the mountains of New Zealand, Sir Attenborough discovers one from a population of only 40 pairs. Finally, another example on the brink of extinction is the kakapo, which at one point numbered only 61 individuals. A male is heard calling — an immensely amplified deep note that can be heard at great distances from its nest.

The second programme deals with the mechanics of flight. Getting into the air is by far the most exhausting of a bird's activities, and Sir Attenborough observes shearwaters in Japan that have taken to climbing trees to give them a good jumping-off point. The albatross is so large that it can only launch itself after a run-up to create a flow of air over its wings. A combination of aerodynamics and upward air currents (or thermals), together with the act of flapping or gliding is what keeps a bird aloft. Landing requires less energy but a greater degree of skill, particularly for a big bird, such as a swan. Weight is kept to a minimum by having a beak made of keratin instead of bone, a light frame, and a coat of feathers, which is maintained fastidiously. The peregrine falcon holds the record for being fastest in the air, diving at speeds of over 300 km/h. Conversely, the barn owl owes its predatory success to flying slowly, while the kestrel spots its quarry by hovering. However, the true specialists in this regard are the hummingbirds, whose wings beat at the rate of 25 times a second. The habits of migratory birds are explored. After stocking up with food during the brief summer of the north, such species will set off on huge journeys southwards. Some, such as snow geese, travel continuously, using both the stars and the sun for navigation. They are contrasted with hawks and vultures, which glide overland on warm air, and therefore have to stop overnight.