Stunning Wildlife in the Rivers of Wild Great Britain | Our World

Britain's natural beauty is often overlooked, so let's take a walk on the wild side, over our green and pleasant land, along our rugged coastline and around the 6,000 islands that make up the British Isles. Over one dramatic year, we'll follow the extraordinary wildlife on our doorstep, from the familiar to the surprising. We share this truly special part of the planet with millions of animals. This place we're lucky enough to call home is a natural wonder. Rain. Britain has plenty of it, but as a result, it's blessed with rivers. Over 6,000 of them crisscross the land. A huge diversity of waterways flowing from our highest peaks down to the sea. The animals that live here often go unnoticed, but they're remarkable. Specialists that take on extraordinary challenges, incredible journeys and find opportunities in the most turbulent places in Britain. High in the Yorkshire Dales, a young river tumbles through a secluded glen. It may look magical, but few animals can make a living here. The weather can be harsh and food hard to find, but for one creature, this is the perfect home. The dipper, the only aquatic songbird in the world. It's a clever predator that can unlock the hidden riches of these river rapids. The treasure is underwater and this male knows just how to get it. He does something no other songbird can do. He dives. His bones are solid to reduce buoyancy. His short, strong wings are used like flippers and high oxygen levels in his blood mean he can stay underwater for 30 seconds or more, finding fish and insects hidden under rocks. He's perfectly adapted to life in the rapids, mastering the challenges of the river. There's more to life than catching food. He's also got to impress a mate. A female has arrived on his stretch of the river. As she watches from above, he displays to her and shows off his swimming skills. It may take a while to woo her, but if all goes to plan, the pair will be feeding chicks in a few weeks time. Few other animals venture into the dipper's upland realm, but every year one makes a dramatic entrance. It's the final leg on one of the most extraordinary journeys in the world, Atlantic salmon. They've travelled thousands of miles from Greenland to get here, having survived fishing nets and predators along the way. An incredible journey with one thing on their mind, to breed. After three years at sea, around 75,000 salmon return to British rivers each year, swimming back to the same stretch of river in which they were born, guided by its unique smell. But there's a problem. A series of powerful waterfalls lies between the salmon and their final destination. The salmon are already exhausted after their epic journey. Driven by their desire to breed, they attempt to leap the falls. For a metre long fish, a three metre high waterfall might be a challenge too far, and one that could have an unhappy outcome. A misjudged leap could end in a lethal landing on the rocks. For those that make it, having already leapt several waterfalls, they're exhausted. One final hurdle lies between them and their destination. finally reaching the breeding grounds. Clean, oxygen-filled water makes this part of the river the perfect place for this female to lay her eggs, and worth the epic effort to get here. She uses the last of her energy to dig a nest. A male moves in. Gentle stimulation encourages her to release her eggs, which he immediately fertilises in a cloud of sperm. She covers the eggs to protect them from being washed away. After their incredible journey, it's no wonder salmon are fondly called king of the river. Our rivers slow as they meander through the lowlands, creating quiet pools. The ideal hunting ground for a tiny jeweled bird, the kingfisher. This male is a master fisherman. He needs to be. He must catch and eat his body weight in fish every day. Roughly 40 grams. It might not sound much, but when your food is a one gram minnow, that's 40 fish a day. He's not only catching food to eat, he's courting a queen. He presents her with gifts, tokens of his affection that win her heart. Now the hard work really begins. Kingfishers nest in riverbanks, digging a tunnel up to a metre long. The new couple shares the task, making a safe place to raise their young. The effort's worth it. A month after courtship, the pair are proud parents to very demanding chicks, and their fishing quota shoots up to 150 fish a day. It takes another month of frantic fishing before their babies leave the nest. They decorate our quiet riverbends with a royal flash of brilliant bloom, leaving mum and dad to take it easy again. Britain has cleaned up its waterways over the last 40 years. As a result, many of our rivers are healthier than they've been in centuries. Good news for our weirdest river residents. Insects. These alien-looking creatures are in fact young flies, known as nymphs. They only live in clean water, so their presence is a welcome sight. They spend most of their lives on the riverbed, remaining in this juvenile form for months, sometimes years. Their feathery gills extract oxygen from the water, and they feed on microscopic food in the flow. They in turn are food for fish and birds, so are a vital part of any healthy river. When warm spring weather triggers them to transform into adults, it creates a magical natural event. One that makes this chalk river in southern England world famous. Born in an underground reservoir deep in the Hampshire Downs, its water is filtered and purified by permeable chalk rock. There are only 200 chalk rivers on earth, and 85% of them are in England. The River Test tops the list for its beauty and abundant wildlife. The pristine water is full of life. Warm May weather signals the moment when Mayflies start their journey from life underwater, through a series of molts, to a life above. The alien-like bug begins its transformation, crawling out of its wingless form to become an adult, with delicate lace-like wings, ready to take flight. The angelic adults live for only a few hours. In that time, they must find a mate and lay eggs. A brief magical moment in the Mayfly's life, but an event that makes this river forever special. Its final task completed, the adult falls back into the river, joining millions of other dead and dying Mayflies. A huge variety of river life depends on this moment. Fish and birds gorge on the flies. It provides an annual feast for a particularly important river dweller, the brown trout, and the event draws fishermen from around the world. Looking after these eager anglers is a job that falls to river keepers, like Nick Parker. Each morning, he patrols the banks of his stretch, carefully monitoring the health of its plant and animal life. Nick's from a family of river keepers born and raised just downstream, so he knows this river like the back of his hand. His knowledge and experience is especially important when the anglers arrive in May, a key month in every fly fisherman's calendar. Predicting the exact time of the Mayfly hatch, and therefore the best fishing, is down to Nick. He's their eyes on the water, short-cutting hours of waiting, and taking the anglers to where the fish will most likely be. The river Test is considered to be the birthplace of modern day fly fishing. If it wasn't for the pristine water, there'd be no Mayflies, no trout, and no fly fishing. Back in Yorkshire, a month after their courtship, the dippers now have three hungry chicks, and are busy feeding them insect nymphs plucked from the river. They've built their nest on a rock face right above the water. It's precarious, but it's there for a reason, to keep their young safe from predators, like the stoat that regularly patrols the bank. The family home is still at risk. A wet spring and a flash flood could easily wash it away. Undeterred, these plucky parents work around the clock to feed their chicks. Spring storms can raise river levels very quickly, but this pair know what they're doing. Their perfectly positioned nest has kept their family safe. Three weeks after they hatched, the baby dippers face their next challenge, to learn to dive for food, just like mum and dad. The riverbank is the ideal place to watch and learn. The parents have done a great job raising their chicks, and in just two weeks' time, the young dippers will move on to their own stretch of river. We have over 50 species of freshwater fish in our waterways, from tiny minnows to colossal carp. Each favours different conditions and a different way of life. One even seems to have a personality, the grayling. It's a smaller, more flamboyant relative of the salmon, and its elegant fins give it the nickname Lady of the Stream. Like their better-known cousins, grayling migrate to their breeding grounds every year, but their journey is rarely more than a mile. They save their energy for romance. The males are the first to arrive and start scouting for a love nest. One finds the ideal spot, with a gentle current and a fine bed of gravel. How could a lady refuse? His only problem? Other males. The eager Romeos soon come to blows. He manages to hold his ground. Eventually, the females arrive. They like what they see. The champion grayling is quick to make his move. He caresses her side and lets passion take over. It's 50 shades of grayling on the riverbed. Healthy rivers mean plenty of fish, which is why one of our most lovable river residents is bouncing back from the brink of extinction. Lines of bubbles, a loud splash, and a furred tail disappearing under the surface. All signs of the elusive otter. Under the cover of darkness, a mother leads her two cubs along the river. They're only a few months old, and they still have important lessons to learn. It takes a year for an otter to master fishing, so the mother wastes no time teaching them. The loose rocks hide tiny nymphs. It takes a bit of searching and digging through the stones. A handy snack on the go, but it's fish she's really after, and she's perfectly built to catch them. Her sleek shape, broad tail, and webbed feet power her through the water. But her hunt comes to nothing when the playful cubs ruin it for her. They still haven't grasped this important life lesson, but for now they have time on their side. Families like this are an increasingly regular sight. After a long absence, otters can now be found in every county in Britain. While our otters have made a welcome return, another special river character needs a helping hand from a group of dedicated people. Hunted to extinction, beavers haven't been seen in Britain since the 16th century. Long enough to be mistaken for foreigners, but the fact is beavers are true Brits, and they're on their way back. A key player in helping their return is ecologist Derek Gow. His barns no longer house sheep and cattle, but beavers. In 2006, Derek started a breeding programme. He now has 20 of these giant rodents ready to be released into the wild. Beavers are nature's great engineers. They build dams to create pools around their twig-constructed home, known as a lodge. This deep, slow water provides a sanctuary where the beavers can live safely. Unlike otters, beavers are vegetarian, and these pools give them easy access to the plants and trees that make up their diet. Beavers are well adapted for their aquatic lifestyle, with webbed hind feet and a large, flat tail that acts like a rudder in the water. A slap on the surface warns of any danger to other beavers. A thick, waterproof coat takes a lot of looking after, and hours can be spent keeping it in tip-top condition. Grooming together helps secure bonds amongst the extended beaver family, called a colony. The pools created by beavers not only give them a safe place to live, but transform small streams into wetlands, providing new homes for a huge variety of British plants and animals. Pools also help clean up our rivers. They act like natural sponges, capturing polluted water as it runs off farmland, and purifying it before it heads downstream. All good reasons to release a pair of captive-bred beavers into the wild. The release site has been carefully selected. It has everything a beaver family could want. Five acres of river, pools and plant life. This is an historic moment for British rivers, drawing crowds from across the country. The crates are in place, the cameras are ready, bring out the beavers. It only takes a moment to realise that they're free, and they immediately start exploring their new home. It's the first time a beaver has swum in a Cornish river in over four centuries. The release is a great result for Derek and the team. The beavers' impact will be carefully monitored, but it looks like they're set to become permanent residents of Cornwall's rivers once again. As rivers continue their journey from source to sea, they provide challenges and opportunities along the way. Flowing through the Scottish border town of Dumfries, the River Nith is nearing the end of its journey. Migrating fish are moving upriver, but this weir is as far as many will get. Their arrival goes largely unnoticed by humans, but not by the local wildlife. A gooseander, a sawbill duck, named for the serrations on its beak that help it grip its prey. Green-headed males and russet-headed females gather together. There may be plenty of fish, but catching them is another matter. If anything can succeed in these turbulent waters, it's these streamlined specialists. They can dive as deep as four meters and stay underwater for over a minute, so it's only a matter of time before one comes up trumps. The weir is a barrier to some, but a fantastic opportunity for others. As our rivers reach the coast, they enter the last stages of their life, but it's not the end of what they have to offer. On Scotland's east coast, where the Bewley and Ness rivers flow into the Moray Firth, rare and intelligent animals arrive at a certain time of year. Bottlenose dolphins. They're here to take advantage of an annual natural event. One that draws them close to land and within easy view. In June and July, thousands of migrating salmon arrive at our coast en route to their breeding grounds. A potential feast for the dolphins. But what brings the dolphins here, so close to shore? The answer lies in the unique geography of this location. Two points of land that jut into the Moray Firth, squeezing the incoming tide into a narrow gap and carrying the migrating salmon with it. The dolphins know that the tide flows faster as it races around the point. The perfect spot to sit and wait for salmon to be brought to them, as if on a conveyor belt. Why waste energy chasing after a meal, when the meal can be brought to you? This group of dolphins is the only one known to hunt in this way. Their strategy has been passed down from generation to generation. Every now and then, the dolphins catch a huge salmon, up to 10 kilos in weight. Too big to swallow in one go. It can take 45 minutes to get the angle just right, but the effort is worth it. There's nowhere else on earth where dolphins are guaranteed to come so close to land, and so often. Which is what brings thousands of visitors from all over the world to to enjoy this natural spectacle. Back on the west coast, just south of Dumfries, the river Nith finally reaches the sea. It slows and drops its load, ton upon ton of nutrient-rich silt, carried down from the hills, creating vast mudflats and fertile marshes. The estuary is a critical feeding ground for over 80,000 birds. Half of those are barnacle geese, escaping the arctic winter. In the fading light of an October evening, the geese begin to arrive. They've flown 2,000 miles south, non-stop, for three days across the open ocean. This year's young are only four months old, and stick close to their parents. It's their first migration, and they're exhausted. They've traveled all this way for this. A perfect stretch of succulent grasses, fertilized by rich river deposits. Within days, over 40,000 geese, the entire population from the Norwegian Arctic, will be feasting on these precious blades of grass. This gift from the river will see them through the winter, and fuel them up for their return north in spring. Britain's rivers are some of the finest in the world. Numerous and varied, from bubbling mountain brooks, to gin-clear chalk streams, to mature languid waterways, and vast muddy estuaries. Some are the cleanest they've been in decades, allowing incredible diversity. And a welcome return by some of our favorite river characters.