Series celebrating the infinite variety of the natural world and its depiction in culture. In the final episode of the series we present our swan song. Ethereally white and otherworldy, the Swan has featured in countless fairytales and myths. Brett Westwood gets up close with bird itself, paddling and snuffling his way through 2000 years of cultural history. On its way he visits ancient Greece, Swan Lake, and Putin's Russia. He hears the swan-infused poetry of WB Yeats, and finds out whether a swan can really break your arm. With contributions from: Kevin O'Hare - Director of The Royal Ballet Fumi Kaneko - First Soloist, The Royal Ballet Edith Hall - Professor of Classics, Kings College London Sacha Dench and Kevin Woods - Wildfowl and Wetlands Trusts at Slimbridge David Barber - Queen's Swan Marker Chris Perrins - Queen's Swan Warden Waldemar Januszczak - Art Critic, The Sunday Times Suki Finn - Philosopher, University of Southampton Reader: Deirdre Mullins

Its arguable that a certain dinner-suited bird has captured our hearts and minds more than any other creature over the centuries. As Brett Westwood discovers, penguins remind us of ourselves - like us they stand upright, they travel in groups, they communicate all the time and they walk (or waddle) on land. They have both entertained us and taught us life lessons. Our earliest encounters with Penguins very often resulted in the slaughter of these flightless birds for food and oil and they may well have gone the same way as the Great Auk had public campaigns to put an end to their slaughter not been successful. Since then, they have been adopted as a brand name for books and biscuits, inspired music, animations, films, TV shows, children’s stories and there is even a Penguin Post Office, surrounded by penguins, on a tiny island in Antarctica where you can post a card with a penguin stamp. Producer Sarah Bunt Contributors Henry Eliot - Editor of Penguin Classics Arthur Jeffes - Composer, Musician and frontman of the musical group, Penguin Café Stephen Martin - writer and Antarctic Historian Camilla Nichol - Chief Executive of the UK Antarctic Heritage Trust Ruth Peacey - Film-maker and Ornithologist Douglas Russell - Senior Curator of Birds, Nests and Eggs at the Natural History Museum in Tring Cleopatra Veloutsou - Professor of Brand Management at the University of Glasgow Adrian Walls - Assistant Zoo Manager. ZSL London Zoo and Reader - Elizabeth Counsell

The story of our relationship with Orchids is a story of obsession, money, deceit, beauty, femme fatales, ghosts deception and let's be honest, sex. Orchid flowers come in a variety of colours, shapes and sizes - but they all have one thing in common - they have evolved to maximise their chances of luring a pollinator and be fertilised - and they do so with such style! It's easy to see why have they captivated and lured us too! Producer Sarah Blunt.

Dogs have changed us and we've changed them. Brett Westwood visits Battersea to meet the animals whose history is most inextricably linked with our own. And in the process very nearly loses a furry microphone cover to an enthusiastic lurcher named Trevor (pictured above)... As the first domestic animals, dogs made it possible for humans to spread into the areas of the world that they did, to eat more protein and to take up activities from hunting to sledding. But it was only in the Victorian period that the dogs we know today were "invented", by breeding. And throughout all of this dogs have also been changing human lives as companions. Producer Beth O'Dea Taking part: Professor Greger Larson, Director Palaeogenomics Bio-Archaeology Research Network, School of Archaeology, University of Oxford Dr John Bradshaw, anthrozoologist and author of In Defence of Dogs and The Animals Among Us Susan McHugh, Professor of English at the University of New England Naomi Sykes, Lawrence Professor of Archaeology at the University of Exeter Julie-Marie Strange, Professor of British History at the University of Manchester Dr Krithika Srinivasan, Lecturer in Human Geography, University of Edinburgh

Brett Westwood on the Komodo dragon - myth, monster and reality. With contributions from Mark Carwardine, Antonia Quirke and Joe Capon of the Attenborough Komodo Dragon House.

Holding what looks like a television aerial, reptile ecologist Nigel Hand strides across the heath. It may look something out of a science fiction movie, but as Nigel explains to Brett Westwood he is on a serious quest; searching for adders. These adders he has previously caught and fitted with tiny radio transmitters and the aerial is used to track and follow them as he learns more about the behaviour and habits of these much misunderstood snakes. Like Nigel, Brett Westwood has been fascinated by adders since he was a child and as he discovers they have long been the subject of myths and superstitions often attributed with powers of wisdom or a sly nature, giving rise to stories about their ability to hypnotise their prey and swallow their young. But as Brett discovers the truth about our only venomous snake is even more fascinating. Producer Sarah Blunt.

Brett Westwood explores our relationship with an Arctic Legend, the Narwhal. This Unicorn of the Sea is not only extraordinary in appearance, but tantalisingly difficult to study!

Brett Westwood looks at the history of a bird which has become a byword for male beauty. It's all about the tail: inspiration for everyone from Darwin to Oscar Wilde, from poets to peacocking pop stars. In Lancashire, Brett walks among peacocks of every shade and type, and with colour scientist Pete Vukusic explores the secrets of the bird's shimmering, iridescent appeal. Laurence Llewelyn-Bowen, a natty dresser himself, explains the birds influence on pioneering artist Aubrey Beardsley, and Maan Barua reveals the enduring influence of the bird in its native India - traded as a gift for centuries, and elected as a national symbol following independence. Producer: Melvin Rickarby

With its playful, hand-holding, pebble-juggling ways, the otter wins the cuteness contest with its eyes closed. It's no wonder such a stunningly elegant and charismatic animal has been the star of films and books and the inspiration for thousands to make pilgrimages to rivers in Devon or rings of bright water in Scotland. But do not be deceived. As Brett Westwood discovers, this elusive wild animal is a skilled and ferocious predator and, given half a chance, he'll have your fingers off! Writer Miriam Darlington shows Brett the paw prints on the banks of the river Dart, and describes the first time she ever saw an otter. Anthony Phillips, once the guitarist for global pop group Genesis, now composes music for screen and, he tells us, it all started with reading and feeling compelled to make music inspired by Tarka. Dr Elizabeth Chadwick, who manages to slit otters open for science, explains how the otter's insides are a barometer of health for our environment. Dr Daniel Allen charts the history of otter hunting from anglers removing fish-eating vermin, to a Great British summertime sport, and the legislation that saved them. and Olivia Morgan reads Robert Macfarlane's spell for conjuring an otter, over the watery sounds of Joanna Newsom's Divers, in an attempt to evoke the slippery land fish that inspires such awe, devotion and fear. Producer: Ellie Richold.

Brett Westwood explores how our idea of the dung beetle has morphed over the ages. The most sacred symbol in Egyptian ideology, the scarab beetle was also the butt of Classical Greek jokes, the inspiration for anti-conceptual art, the go-to filthy vermin for use in moralising fables and more recently the source of celestial wonder for poets. Brett visits an enormous scarab sculpture at the British museum with entomologist Richard Jones, who has brought along his collection of favourite shiny bugs. Biologist and cartoonist Jay Hosler explains why his character Sisyphus is the wisest creature in his graphic novel Clan Apis. Dr Rachel Murray from the University of Bristol reveals the entomologist Fabre's influence on DH Lawrence's Ladybird. Producer Simon Bell explains just how much baby elephant manure it takes to film a dung beetle and Billy Childish revels in the elementary appeal of a creature that sculpts, rolls, battles over and eats poo. Producer: Ellie Richold.