The woodlands of the British Isles are magical and mystical places, but as one of the least-forested countries in Europe*, they are also under threat. Sir David Attenborough follows our woodlands through the seasons, revealing a host of spectacular animals and the hidden dramas that rule their lives.

In the deep winter, a layer of snow keeps a hungry robin from the worms beneath. The reintroduction of wild boar to the Forest of Dean gives the little bird a lifeline, as the boar unearth worms with their snouts in a surprising and fruitful partnership.

As the snow recedes, a mass explosion of pollen forms great clouds above the yew trees in Kingley Vale, West Sussex – so much is released that the landscape appears on fire.

Come midsummer, a slimier creature emerges at night in our temperate rainforests. The ash-black slug is the largest land slug in the world, and its unusual mating mechanism needs to be seen to be believed…

Autumn brings fallow deer and fungi, and we travel underground to see how a subterranean network of fungi known as the Wood Wide Web connects the whole forest together, passing vital nutrients and information between trees.

As our seasonal journey comes full circle, night cameras reveal shocking behaviour in a starling roost. Using thermal camera technology, we see for the first time what really happens when these birds settle for a night’s sleep in woods on Bodmin Moor, as owls swoop in and carry off the slumbering starlings.

This episode uncovers complicated and delicately balanced woodland systems, as organisms live and die together in complex harmony. Since Sir David Attenborough was born, we have lost almost half of our ancient woodlands, and now only 13% of our isles are covered by trees. If we can bring back the woodlands we have lost, there will be more spectacle, drama and intrigue for everyone to enjoy.