As I see it humanity needs to reduce its impact on the Earth urgently and there are three ways to achieve this: we can stop consuming so many resourc… - David Attenborough

If you watch animals objectively for any length of time, you're driven to the conclusion that their main aim in life is to pass on their genes to the next generation. Most do so directly, by breeding. In the few examples that don't do so by design, they do it indirectly, by helping a relative with whom they share a great number of their genes. And in as much as the legacy that human beings pass on to the next generation is not only genetic but to a unique degree cultural, we do the same. So animals and ourselves, to continue the line, will endure all kinds of hardship, overcome all kinds of difficulties, and eventually the next generation appears. This albatross is over 30 years old, she's already a grandmother, and this year once again she has produced a chick. She will devote the next 10 months of her life looking after it. She has faced the trials of life and triumphed, for her little 2 day old chick the trials are just beginning.

An eye from another world; a smell-detector, investigating the path ahead. We don't often see a snail that way, and that's because we've only recently had the tiny lenses and electronic cameras that we need to explore this miniature world. But when we meet its inhabitants face to face, we suddenly realise that their behaviour can be just as meaningful to us as the behaviour of many animals more our own size.

The island is immense. It's 1,000 miles long, if you discount a narrow arm of sea that crosses it in the middle, and it contains mountains over 12,000 feet high. It's New Zealand. The first land-living mammals to get here were human beings and they didn't arrive until a mere 1,500 years ago. So here you can glimpse what the world would have been like if the birds had won that battle with the early mammals and now ruled the Earth, for here they once did.