Secret Life of the ForestEpisodes Guide

Cameras capture the various wildlife residing in England's most vast forest, including roe deer, red squirrels and more, as changes occur throughout the seasons.

It's summertime in Kielder Forest, the sound of buzzing insects filling the air and all wildlife facing a race to make the most of the sunshine.

Despite its rich biodiversity, Kielder Forest didn't exist a century ago. It was created to help provide the country with timber and has evolved to become a wildlife refuge.

It's winter in Kielder Forest and while some wildlife battles to survive, others sleep.

It's summer in Yorkshire and inside the county's largest forests, Dalby and Cropton, the lengthening days bring a surge of life. We meet the beaver family who were established in Cropton in 2019 as part of a scientific trial to see how they would change the landscape. They have since got to work building dams and creating the perfect watery environment for these amazing architects of the natural world to live in. We follow these incredible creatures as they progress over the summer. Elsewhere in the forest, the signs of the new season are all around. As the temperatures rise, there is a chance to be reacquainted with those animals absent from the forest over the winter. Some creatures have been asleep through the colder months, like Britain's only venomous snake, the adder, now out soaking up the heat of the sun. Birds return to Dalby after spending winter in Africa. There is an array of new life in the forest. A team of bird conservationists are on the lookout for nightjars: a bird that has made a perilous journey of thousands of kilometres to spend the summer in Yorkshire. They try to catch one in specially designed nets so they can ring it and collect data, but it is not such an easy task. Meanwhile, in a different part of the forest, the world's largest dry stone wall maze is being built. It's an epic project needing 5,000 tonnes of stone and years of careful building using this ancient precision craft. It's one man-made wonder amid this landscape of natural beauty.

Summer is now in full swing in Yorkshire's Dalby and Cropton Forests. With the passing of the solstice, the days may be shortening but the heat is building. At the beaver pond in Cropton Forest, cameras reveal the family continuing to transform their habitat by building dams and reshaping the landscape. Meanwhile, a group of six Exmoor ponies feed on hardy vegetation, which allows for wildflowers and orchids to grow.

In Yorkshire the great British summer is in full swing. But this year the sun is blazing hot as Dalby and Cropton forests are in the midst of a heatwave. Record-breaking temperatures in the area are reading as high as 38 degrees celsius and the forest is drier than ever. For some creatures the heat could be deadly, with bumblebees forced to stay in their nests so they don't overheat. Fortunately for the resident beavers, while they may be wrapped in thick fur, their cleverly constructed dams have created deep ponds of cool water. It is an important time for the family: Mummy beaver hasn't been seen recently and it is thought she has given birth to kits - the name for beaver babies. Beavers can give birth to up to four kits at a time, so forest ecologist Cath is on a mission to discover just how many new members of the family there are. Elsewhere, it is hoped Dalby can play a crucial part in the survival of Britain's most endangered bird, one that is on the brink of extinction: the turtle dove. A band of dedicated volunteers monitor the appearance of this elegant bird, which makes a gruelling 11,000 kilometre round trip from Africa every year. Through their hard work Dalby Forest has become one of the country's most important sites for this dainty songbird. We also follow Wildlife Manager Nigel, who has one of the forest's most challenging jobs: to ensure the forest habitat is healthy for all the animals that live in it, he must investigate the tree damage caused by deer and then monitor their population and work out the right animals to cull. It is a big responsibility, but a necessary job to preserve the forest for future generations.

The warm Summer days continue in Dalby and Cropton Forests. The lack of rain even sees Yorkshire on the brink of drought status. But at the beaver pond their work continues, creating the perfect watery habitat for the family to thrive in. Now they have two young kits to teach all their incredible building skills. Having built a dam over seventy metres long, they have now moved on to other construction projects as they appear to be expanding their territory. For the baby beavers it is set to be some education. With secret cameras across the forest, we are able to see some of the forest's other youngsters investigating their new surroundings, from fawns nervously exploring, to badger cubs appearing out of their setts for the first time and learning how to play-fight with their siblings. These cameras also help us watch the life around the beaver pond. Since their arrival in Cropton, there has been a dramatic increase in many other species. Their pond is now teeming with frogs, toads, fish and the scary looking lamprey. All these creatures are tasty meals for herons. We watch these top predators on the hunt, lurking by the water, their beady eyes focussed looking for any sign of movement, ready to strike at any time. Elsewhere, we explore the special tufa fens in the area with their calcium-rich water running through the valley. These meadow habitats are rich with special flowers and butterflies. It's easy to forget in such idyllic places that in other parts of the forest there are beasts of a different kind at work. Giant machines able to fell and strip a tree in a minute are creating 20,000 tonnes of timber a year. Dalby remains an important working forest with a big commercial timber operation, although there remains plenty of room for wildlife to thrive.

It's the height of Summer in Dalby and Cropton Forests and the inhabitants are making the most of the abundance the warm weather provides. The forests are a hive of activity. Nowhere more so than the beaver pond. The young kits born earlier in the Summer are now starting to explore further afield. But we see how they are bonding with the rest of the family during one of the beavers' most important tasks: grooming. Keeping their thick fur in the best possible condition is vital, while also being a chance to get close to your nearest and dearest. For the kits it's not all about grooming – as nature's great lumberjacks, they will soon need to master the skill of tree chewing. Gnawing through bark is no easy task, but a beaver's famous two front teeth are the perfect tools for the job, and we witness them at work. The forest is a place that celebrates its recent history as we learn about the Lumberjills, the affectionate name given to the women who worked in the forest during World War Two as part of the Women's Timber Corps. The war brought with it an increased demand for timber building material, but with the nation's men fighting overseas, Dalby needed women to take up the saw. We meet some modern day forest heroes in the form of rescue dogs Ollie and Slate. The North York Moors National Park has over 1400 miles of paths and trails running through woods and across moorland. They are explored by eight million visitors every year and accidents can happen. In an emergency highly trained volunteers from the local mountain rescue team are called. Hoping to become part of the team is two-year-old Slate, who is undergoing a rigorous training programme. Will he pass the test?

With autumn well on its way, much of the wildlife in Dalby and Cropton Forests prepare for a new season and all that it brings. Over at the beaver pond, ecologist Cath is keeping a close eye on the family, as the older siblings begin to show signs of causing conflict in the wider group. Meanwhile, apprentice forester Holly must master using a chainsaw as the team cut down trees that could be risky to the public.

Summer is coming to an end in Dalby and Cropton Forests. After record breaking temperatures, the air now feels fresher. But with the leaves already turning orange and the berries ripening, August is seeing a false Autumn taking place, caused by heat and drought. At the beaver pond, it's at this time of year you have a good chance of seeing one of the great sights of British wildlife: the kingfisher. They can be seen perched on a branch sticking out of the beaver dams, a captivating presence with their vibrant colours of turquoise and orange. Then, in a flash, they dive head first into the water and emerge with a catch. Deep in the forest, the search is on for a much harder creature to spot: the pine marten. Once a common sight in North Yorkshire, hunting and a loss of woodland put them on the brink of extinction in England. It's only in recent years there have been exciting developments suggesting they are back in our forests. They are now one of Dalby's rarest animals with a dedicated team using motion sensitive cameras to try and capture footage of them. But it's been months since a pine marten has been caught on camera, so will we see any evidence that they are actually here in the forest? We meet another team on the hunt for bats in Cropton. Since the beavers arrived it's believed the number of bats has increased, but they need proof, so armed with specialist equipment they are on a mission to count the number of bat passes in the area to discover if there really are more bats here.

It's the start of autumn in Dalby and Cropton Forests. Change is in the air as the sun's power is fading. After months of warm weather, and even a false autumn, more leaves are beginning to turn a golden yellow and many of the birds are preparing for their migration south. Life among the trees might seem to be slowing down, but underneath the canopy there is a transformation taking place. It's showtime for one of the delights of autumn: fungi.There's a final visit to the beaver family in Cropton. Having spent summer hard at work, building dams, increasing flood plains and having two young kits to look after, we follow the beavers in the run up to autumn. They work at an astonishing speed, late at night and in the early mornings, so every visit is full of surprises.Throughout the summer, apprentice Holly has become embedded in forest life. She's now a master of the chainsaw and is becoming an expert on all the trees that grow in the forest. With her exams approaching, she learns about threats to the trees and how important it is to identify vulnerable trees, which might be prone to breaking or falling down.Alongside the animals and plants that call Dalby home, we meet some four-legged friends who are visiting to take part in a very special event; the Canicross. The canine competitors of the race come in all shapes and sizes and, having never previously had a Chihuahua take part, the organisers are in for a surprise.