Sir David Attenborough explores the surprisingly vibrant seas that surround the British Isles. The vast watery wilderness around us is over three times the size of our land mass, and yet to many, our oceans remain a mystery. Full of colour and teeming with life, the seas of Britain and Ireland are crucially important to a range of wildlife. This episode goes beneath the waves to uncover the thriving habitats that exist along our 22,000-mile coastline.
In winter, clear evidence of the ocean’s abundance can be seen on a beach in Norfolk. Thousands of grey seals congregate on the shoreline to give birth. Britain and Ireland are home to 40 per cent of the world’s grey seals, and the number being born on our shore rises every year. Once the newly born pups are weaned, the females are ready to breed again, and heavyweight males enter violent, bloody fights to win a stretch of beach, and the females along with it.
Beyond the beach, the vibrant shallows contain several important habitats. Rich beds of seagrass are nurseries for a range of animals, while also acting as very important carbon storage areas. They are also home to one of the strangest fish in our waters, the seahorse. We follow a male and female as they perform a balletic mating dance in the water, delicately entwining their tails. The stakes are high, as these animals mate for life.
In a touching piece to camera, Sir David bids a fledging Manx shearwater chick farewell as it embarks on a 6,000-mile journey across the oceans to South America. There is no better example of how important the British Isles and its abundant seas are to the survival of wildlife worldwide.

David Attenborough explores Britain and Ireland’s grasslands, revealing the creatures that create them and the extraordinary stories they hide. From the coastal flower meadows in the Scottish Outer Hebrides to the rich open landscapes in the mountains of southern Ireland, we enter surprising and dramatic worlds.
In southern England, we meet an extraordinary bee that lives in chalk grassland, one of our rarest habitats, laying her eggs in empty snail shells. Meanwhile, in the colourful machair of the Hebrides, ringed plovers and lapwings strive to rear their families of tiny fluffy chicks and to save them for marauding gulls.
We travel back in time to explore the vast wild grasslands once found throughout our isles, before meeting herds of semi-wild horses, where males battle fiercely for the females. Today, they are helping to turn some of this land back to wilderness. And in our precious remaining pockets of flower-rich meadow, a remarkable conservation success story plays out. Once extinct in our isles, England now has the largest known populations of large blue butterflies. Their survival relies on a game of deception with red ants, which are tricked into adopting the butterfly’s unassuming but predatory caterpillars.
Our story then journeys to the mountains. Each morning in early spring, feisty male black grouse battle for prime position on their frozen breeding grounds. Their sole mission is to impress a female. Meanwhile, on south-facing scree slopes, dozens of adders emerge from hibernation to perform a surprisingly delicate courtship routine.
The episode concludes with a mighty battle in the wild mountains of County Kerry. This is the scene of an epic and spectacular rut between the largest land mammals in Britain and Ireland, red deer.
The grasslands of Britain and Ireland are under threat. We have lost 97 per cent of our species-rich meadows in the last century, as modern agriculture replaces these precious habitats. This episode shows just how important different types of grassland are to the species which call these islands home.

Sir David Attenborough explores the incredible diversity of Britain’s woodlands, taking us on a seasonal journey through our forests, and revealing a host of spectacular animals and the hidden dramas that rule their lives.
In an ancient pine tree in the Cairngorms, two eagle chicks are on the verge of fledging their gargantuan nest. In winter in the Forest of Dean, the reintroduction of wild boar has given the robin a lifeline. As they root through the thick snow, the boar unearth the worms with their snouts, which the robins otherwise couldn't find.
Back in Scotland, a male capercaillie displays to gathering females. These birds are on the edge. With only around 500 left, they are some of the rarest and most threatened in the British Isles. In a beech woodland outside London, the deciduous trees burst to life in spring, and huge colonies of wood ants awaken and go looking for food. Also looking for sustenance is a female roe deer. With no large predators left in our woods, the deer are free to browse on new growth to the extent that they can damage the woodland itself.
In Sussex is an ancient-looking landscape, but one that has only been recreated in the past 20 years. This is the wood pasture of Knepp, created by using old grazing methods that generate a mix of scrub, open areas and ancient trees. In the Scottish Highlands, red squirrels battle it out for access to ripe pine cones at the top of a tree. It’s an acrobatic and energetic encounter, with more than a little cunning required to win the day. As the summer finally fades, we encounter a honey buzzard nest, where two chicks feast on wasp grubs, squabble between themselves and grow up before our eyes.
Autumn brings the fallow deer rut. The woods resonate with their calls, and bucks fight for supremacy. The season also brings colour, both in the leaves but also in the fungi that fruit at this time of year. The mushrooms are just a tiny part of their story, however, and we travel underground to see how the wood-wide web connects the whole forest together.

A Tyrannosaurus and two Quetzalcoatlus fight over an Alamosaurus carcass. A shoal of Sphenodiscus are ambushed by a Globidens, intent on surplus killing them. At an evaporating lake, juvenile Pectinodon hunt flies while their father hunts Styginetta. Male Triceratops fight and display for the right to mate. A female Nanuqsaurus hunts Ornithomimus to feed herself and her offpsring.

A female Phosphorosaurus hunts lanternfish under the ocean's moonlit surface. Hesperornis hunt for fish until they themselves are hunted by Xiphactinus. A Mosasaurus hunts a group of Tuarangisaurus. Nostoceras hatchlings are at the mercy of the tides and juvenile Pyroraptor. The young Nostoceras that survived find themselves among Baculites and Diplomoceras in their new seagrass meadow home. A pod of Morturneria sift the muddy seabed in search of food.

Female Isisaurus traverse the Deccan Traps to reach their nesting site. A mixed herd of sauropods and Prenocephale navigate a maze of canyons, but are ambushed by a pack of Velociraptor and a trio of Tarbosaurus. A colony of male Corythoraptor protect their eggs from the scorching sun by day, and a female Kuru kulla at night, who has offpsring of her own.
Trudging through a scorching desert, two young Tarchia find relief at an oasis and encounter an adult twice their size, ready to lay claim. Several Isisaurus hatchlings fall prey to Rajasaurus in an attempt to reach their ancestral home.