0:00:50 > 0:00:51It's 3:30 in the morning.
0:00:51 > 0:00:55Now it takes something pretty special to get me out of bed at this time of day,
0:00:55 > 0:00:59but I've come to see the start of a spectacular daily show.
0:01:16 > 0:01:20- BIRDSONG - Here we are, best seat in the house and I think I'm only just in time.
0:01:20 > 0:01:24The overture's beginning. Who's first up?
0:01:24 > 0:01:26The robin!
0:01:28 > 0:01:29Blackbird...
0:01:32 > 0:01:34Song thrush - always nice to hear.
0:01:37 > 0:01:42One starts and then suddenly within seconds, they're all joining in.
0:01:46 > 0:01:50It's as if they're all taking their four-part harmony now.
0:01:55 > 0:02:00So, woodland that five minutes ago was absolutely silent
0:02:00 > 0:02:02is now ringing.
0:02:05 > 0:02:09It's the most evocative sound in our wildlife year.
0:02:09 > 0:02:16At its peak, more than 70 million birds across the country join the spring dawn chorus.
0:02:16 > 0:02:23It signifies a special place, a wildlife habitat packed from floor to canopy.
0:02:33 > 0:02:37The forest is a magical and mysterious place.
0:02:41 > 0:02:44The source of folklore and fairytales.
0:02:44 > 0:02:50It's plain to see how ancient peoples conjured up all manner of mystical beasts
0:02:50 > 0:02:54to live among the gnarled branches and forest mists,
0:02:54 > 0:02:58but the real forest is even more extraordinary.
0:02:58 > 0:03:03So join me on a journey where the plants and animals might seem familiar,
0:03:03 > 0:03:08but the way in which they work together may come as a surprise.
0:03:13 > 0:03:19Woodland is one of our richest habitats, but you'd be hard pressed to see what's living here at all.
0:03:21 > 0:03:26Wildlife's very good at making itself scarce, especially our first little television star.
0:03:26 > 0:03:32Its nickname is "the monkey of the forest" because it spends all summer up in the trees,
0:03:32 > 0:03:39but in winter and early spring, it sleeps and is almost impossible to find.
0:03:39 > 0:03:41It's the dormouse,
0:03:41 > 0:03:45one of the few British mammals that truly hibernates.
0:03:45 > 0:03:48It finds a comfortable winter nest site,
0:03:48 > 0:03:50not up in a tree but on the ground.
0:03:50 > 0:03:53Its body almost shuts down.
0:03:53 > 0:03:56Its temperature falls to that of its surroundings
0:03:56 > 0:04:01and its heartbeat slows down to a tenth of its normal rate.
0:04:01 > 0:04:08It uses so little energy, it can go for weeks, even months, without moving.
0:04:08 > 0:04:14But on warm winter days, the dormouse can wake for a short time, but that uses up valuable energy
0:04:14 > 0:04:18so it goes back to sleep and the temperature drops.
0:04:29 > 0:04:34Come the spring, its entire body kicks back into life,
0:04:34 > 0:04:39but it doesn't venture far, because the dormouse's summer world doesn't exist yet.
0:04:40 > 0:04:45There are no leaves on the trees to hide it from predators.
0:04:51 > 0:04:56In winter, many of our woodland plants lie dormant too,
0:04:56 > 0:04:59but with the slightest hint of spring,
0:04:59 > 0:05:02the earliest flowers start to bloom.
0:05:04 > 0:05:08It may seem a slow and gentle affair but there's urgency here.
0:05:08 > 0:05:14This sudden burst of spring growth taking advantage of something all plants need to grow...
0:05:14 > 0:05:16light!
0:05:16 > 0:05:19Leaves have yet to appear on the trees, but when they do,
0:05:19 > 0:05:22they'll cut off the light to the woodland floor.
0:05:25 > 0:05:27So there's a race on.
0:05:27 > 0:05:33All the early spring flowers must grow before that light's blocked out and to do that,
0:05:33 > 0:05:38some of them have a hidden store of energy that gives them a head start.
0:05:38 > 0:05:41The primroses are out already.
0:05:41 > 0:05:44These wonderfully bashful, sulphur-yellow faces
0:05:44 > 0:05:47and all around them, the leaves of bluebells.
0:05:47 > 0:05:51In a couple of week's time, this is going to be a sea of blue.
0:05:51 > 0:05:53Of course, the bluebells have an advantage.
0:05:53 > 0:05:56They have one thing the gardener knows about at their roots...
0:05:56 > 0:05:59a bulb, a winter storehouse of food,
0:05:59 > 0:06:03that come the milder temperatures of spring pushes them into life
0:06:03 > 0:06:05and one of the first bulbs to emerge...
0:06:05 > 0:06:07is the daffodil.
0:06:21 > 0:06:26It's a flower show more impressive than anything we can stage.
0:06:39 > 0:06:42Following daffodils are lesser celandines.
0:06:50 > 0:06:55Then come ramsons, the old English name for "wild garlic".
0:07:00 > 0:07:03Next up are wood anemones.
0:07:09 > 0:07:12And finally...
0:07:12 > 0:07:14bluebells.
0:07:28 > 0:07:33With maybe half the world's population in the United Kingdom,
0:07:33 > 0:07:36British woodland is the last stronghold of the native bluebell.
0:07:39 > 0:07:43But this spring race isn't confined to flowers on the forest floor.
0:07:43 > 0:07:49The growing leaves will not only cut out light but also dampen sound.
0:07:49 > 0:07:53So, the great spotted woodpecker stakes his claim to a territory
0:07:53 > 0:07:59before they appear and risks a serious head injury for his trouble.
0:07:59 > 0:08:01He drums rather than sings
0:08:01 > 0:08:06and he's saying, "I'm here and this is my patch."
0:08:06 > 0:08:09It's the original trunk call.
0:08:09 > 0:08:12He always uses the same tree as a sounding board.
0:08:12 > 0:08:19You can tell by the number of holes in it and the more resonant it is, the further the sound carries,
0:08:19 > 0:08:21up to half a mile in some cases.
0:08:27 > 0:08:33It's the human equivalent of hitting a wall face first at up to 20 mph.
0:08:42 > 0:08:48This rush to beat the emerging leaves is joined by some of the trees themselves,
0:08:48 > 0:08:52especially those producing wind-borne pollen.
0:09:00 > 0:09:05Before their own leaves interrupt the flow of air in the woodland canopy,
0:09:05 > 0:09:08willow and hazel join the race to flower.
0:09:22 > 0:09:25Eventually, the leaves unfurl
0:09:25 > 0:09:29and the colourful woodland display comes to an end.
0:09:29 > 0:09:35By May, the trees close the canopy and switch off the light.
0:09:39 > 0:09:42The show on the forest floor disappears
0:09:42 > 0:09:48and our spotlight falls on the creatures hidden away in the depths of the forest.
0:09:48 > 0:09:51With the leaves providing an effective hiding place,
0:09:51 > 0:09:56our "monkey of the forest" behaves just like...a monkey.
0:09:57 > 0:10:01The dormouse's world is the leafy canopy.
0:10:01 > 0:10:04Now he's wide awake, he needs to make up for his winter fast
0:10:04 > 0:10:08and the tree provides something especially juicy.
0:10:08 > 0:10:13Feasting on its fresh green leaves are newly hatched caterpillars.
0:10:13 > 0:10:20They're packed with protein, just the thing to set up a dormouse for his frantically active summer.
0:10:23 > 0:10:28The rapidly spreading leaves are the chemical factories
0:10:28 > 0:10:31that provide the tree with its own food,
0:10:31 > 0:10:32but as with anything in nature,
0:10:32 > 0:10:36if you provide something that's remotely edible,
0:10:36 > 0:10:39then something'll come along and eat it.
0:11:03 > 0:11:08Even with the canopy closed, the floor of most British woodlands
0:11:08 > 0:11:13still receives sufficient light for ferns and other undergrowth to grow,
0:11:13 > 0:11:19but the beech wood, like this one near Oxford, has virtually nothing growing on the forest floor.
0:11:19 > 0:11:22There's a very good reason for that and it's right above me head.
0:11:22 > 0:11:26The beech leaves fit together so closely,
0:11:26 > 0:11:28almost like the pieces of a jigsaw,
0:11:28 > 0:11:33that very few chinks of light make it down to the forest floor,
0:11:33 > 0:11:35as a result of which the ground beneath me feet
0:11:35 > 0:11:39is almost completely devoid of life but there is one survivor.
0:11:48 > 0:11:51This is the bird's nest orchid.
0:11:51 > 0:11:54It might not look much, but there's a good reason for that.
0:11:54 > 0:11:57It grows in the gloom where nothing else can,
0:11:57 > 0:12:02and that means it can't manufacture food with the aid of sunlight and photosynthesise.
0:12:02 > 0:12:05That's why it's this kind of cream colour
0:12:05 > 0:12:08and its leaves have been reduced to these scales,
0:12:08 > 0:12:11but if it can't manufacture food with the aid of sunlight,
0:12:11 > 0:12:14then it has to find alternative means of nourishment.
0:12:14 > 0:12:17The orchid thrives with the help of a fungus
0:12:17 > 0:12:22that lives in the soil and breaks down rotting vegetation.
0:12:22 > 0:12:27The nutrients it absorbs are hijacked by the orchid.
0:12:27 > 0:12:30But the orchid gives nothing in return.
0:12:30 > 0:12:32It's a parasite.
0:12:32 > 0:12:35So by taking advantage of the fungi,
0:12:35 > 0:12:39these delicate flowers are able to survive
0:12:39 > 0:12:41in the dark underworld of the beech forest,
0:12:41 > 0:12:44where less well-adapted species simply fade away.
0:12:46 > 0:12:52With so little light and therefore warmth getting through the canopy,
0:12:52 > 0:12:56flying insects like butterflies tend to make for the woodland edge.
0:12:59 > 0:13:05It's where they'll find the later flowers and the instant energy their nectar provides.
0:13:05 > 0:13:10But in a wood in Hampshire, there's a butterfly that's turned its back on all that
0:13:10 > 0:13:12and it's one creature I'd especially like to meet.
0:13:12 > 0:13:15But to see it, I need to get up there.
0:13:15 > 0:13:18"THUNDERBIRDS" THEME PLAYS
0:13:46 > 0:13:48Lovely!
0:13:48 > 0:13:51Apparently, this is their favourite perch
0:13:51 > 0:13:55and they generally turn up about noon.
0:13:55 > 0:13:58Near enough. OK, do you want to turn her off? Thanks.
0:13:59 > 0:14:01Hah!
0:14:05 > 0:14:07That's a leaf.
0:14:15 > 0:14:17And here it is... a purple emperor butterfly,
0:14:17 > 0:14:19foxy and creamy on the underside of the wings
0:14:19 > 0:14:24and iridescent purple on top. Absolutely beautiful.
0:14:30 > 0:14:32And they're very active.
0:14:32 > 0:14:35Each male butterfly circles in the light,
0:14:35 > 0:14:38defending its own patch of the woodland canopy.
0:14:41 > 0:14:48They'll even see off small birds rash enough to venture into the butterfly's airspace.
0:14:52 > 0:14:56And they go to so much trouble because they have a sweet tooth.
0:14:57 > 0:15:01Butterflies drink nectar, but there are no flowers up here to provide that
0:15:01 > 0:15:04so they need to find another way of getting at it.
0:15:04 > 0:15:09Now butterflies can't pierce leaves but these can.
0:15:10 > 0:15:13Aphids. And they're very messy eaters.
0:15:13 > 0:15:18Aphids tap into the tree's sugar transport system.
0:15:18 > 0:15:24They stab the leaf vein with their needle-like mouthparts and feed on the sugary liquid.
0:15:24 > 0:15:27The system's under high pressure, so they don't need to suck.
0:15:27 > 0:15:33The sugary solution gushes into their stomachs and even spills out of their rear ends.
0:15:33 > 0:15:39The result is a "rain" of sticky, sweet droplets that drip onto the leaves below.
0:15:39 > 0:15:42It's a bit of a nuisance when you park your car underneath,
0:15:42 > 0:15:47but for the purple emperor, it's manna from heaven.
0:15:49 > 0:15:54Using its long proboscis, the butterfly sucks up the sugary puddles.
0:15:54 > 0:16:01So by breaking that traditional tie between the butterfly and flowers, the purple emperor
0:16:01 > 0:16:06has managed to find itself a whole new lifestyle in the forest canopy.
0:16:33 > 0:16:38Now you'll only hear this sound if it's dead quiet.
0:16:38 > 0:16:41MUFFLED SCRAPING
0:16:41 > 0:16:48It's made by something you'd meet more usually out in the open at a picnic or in the backyard.
0:16:48 > 0:16:52But actually the wasp is more at home in the woods.
0:16:56 > 0:16:59The wasp is scraping wood, not to eat,
0:16:59 > 0:17:05but to chew into a pulp and then manufacture its summer home.
0:17:05 > 0:17:09It's a house made entirely of paper
0:17:09 > 0:17:13and the workers construct it one layer at a time.
0:17:17 > 0:17:24Deep inside the nest, neat rows of nursery cells contain the growing wasp larvae.
0:17:27 > 0:17:31The workers feed them chewed up caterpillars
0:17:31 > 0:17:36while the wasps themselves feed on nectar that's passed from one wasp to another.
0:17:40 > 0:17:45It's all very organised - a wasp-making assembly line.
0:17:47 > 0:17:51And there's one creature that's travelled all the way from Africa
0:17:51 > 0:17:55to a wooded Welsh valley to cash in on the product they're making.
0:17:58 > 0:17:59It's a honey buzzard,
0:17:59 > 0:18:05a bird of prey, but one that behaves in a very unusual way.
0:18:08 > 0:18:14It breaks into wasp nests but there could be 10,000 angry workers living inside,
0:18:14 > 0:18:17and they may be small but what they lack in size,
0:18:17 > 0:18:20they more than make up for in ferocity.
0:18:25 > 0:18:27The buzzard's well protected.
0:18:27 > 0:18:31Tightly-packed feathers on its head and face repel stings
0:18:31 > 0:18:36and protective lids prevent damage to its vulnerable eyes.
0:18:36 > 0:18:38The attacks, though, are relentless.
0:18:38 > 0:18:44Each time a wasp stings, it releases a chemical that encourages other wasps to join in,
0:18:44 > 0:18:48but they're not the only ones using chemicals to communicate.
0:18:52 > 0:18:58The honey buzzard itself releases a smell that serves to calm the wasps.
0:19:03 > 0:19:08Although they swarm around the bird, they seem to have forgotten what they're angry about!
0:19:09 > 0:19:12Unlike other birds of prey,
0:19:12 > 0:19:17the honey buzzard has a delicate beak with which it picks out the tasty grubs.
0:19:19 > 0:19:23It rarely destroys the entire nest, but leaves part
0:19:23 > 0:19:27so workers can rebuild it and then it'll return for a second helping.
0:19:30 > 0:19:36After eating its fill, the bird carries a portion of the wasp nest back to its own nest,
0:19:36 > 0:19:40where its chicks are already adept at winkling out the grubs.
0:19:50 > 0:19:53So next time wasps cause you a nuisance,
0:19:53 > 0:19:59remember they also bring the magnificent honey buzzard all the way from Africa
0:19:59 > 0:20:02to breed in our woodlands each year.
0:20:05 > 0:20:08The woods and forests we've visited so far
0:20:08 > 0:20:13have broad-leafed trees that thrive in the relatively mild conditions
0:20:13 > 0:20:16that persist almost all year round in much of England and Wales,
0:20:16 > 0:20:21but north of the border, things are very different.
0:20:40 > 0:20:43In the more remote parts of Scotland,
0:20:43 > 0:20:49trees must cope with probably the most unforgiving climate in the entire country.
0:20:59 > 0:21:05The Great Caledonian Forest once covered much of the Scottish Highlands,
0:21:05 > 0:21:10but due to a change in our climate and the felling of its trees,
0:21:10 > 0:21:13the forest today is a shadow of its former self.
0:21:29 > 0:21:36The trees are pines, birch, aspen, rowan, and junipers
0:21:36 > 0:21:41and they're beautifully adapted to the harsh conditions that prevail in the north.
0:21:43 > 0:21:48The land can be covered in snow for up to a hundred days of the year,
0:21:48 > 0:21:55but the conical shape of many trees ensures the snow slides off their branches so they don't break.
0:21:59 > 0:22:04The sap contains antifreeze so the water inside the tree doesn't turn into ice,
0:22:04 > 0:22:06and of all the Caledonian trees,
0:22:06 > 0:22:09the toughest must be the magnificent Scot's pine.
0:22:09 > 0:22:13It's the world's most widespread conifer,
0:22:13 > 0:22:19and there's one important adaptation that enables it to grow in the most unexpected places.
0:22:19 > 0:22:23The rockface below me is exposed to all the elements
0:22:23 > 0:22:25- wind, rain, snow and ice,
0:22:25 > 0:22:30but amazingly, some trees manage to grow even here.
0:23:02 > 0:23:03Against all the odds,
0:23:03 > 0:23:10this pine tree here has managed to establish itself on this sheer rockface.
0:23:10 > 0:23:14There's hardly any soil here and consequently hardly any moisture
0:23:14 > 0:23:17and what there is freezes in winter.
0:23:17 > 0:23:21Temperatures here can fall to minus 20 degrees
0:23:21 > 0:23:25and winds can reach speeds of up to 140 miles an hour.
0:23:25 > 0:23:27So how does it survive?
0:23:28 > 0:23:30By using these...
0:23:30 > 0:23:32pine needles.
0:23:32 > 0:23:37They are leaves, but they're very, very narrow and they're covered in a waxy coating
0:23:37 > 0:23:39which hangs onto as much moisture as possible,
0:23:39 > 0:23:44so whilst deciduous trees shed their leaves in autumn and grow new ones each spring,
0:23:44 > 0:23:48the pine hangs onto its leaves all year round, saving itself the energy.
0:23:52 > 0:23:56And up among its branches, it also has pine cones growing throughout the year.
0:23:56 > 0:24:04In Scotland's Cairngorms, this gives rise to a sound you wouldn't expect to hear in the depths of winter.
0:24:04 > 0:24:06TWEETING
0:24:07 > 0:24:10They're chicks - crossbill chicks.
0:24:10 > 0:24:14It's rare to find baby birds like these in winter
0:24:14 > 0:24:18because chicks need heaps of food and it's just not available at this time of year.
0:24:21 > 0:24:25But pine cones allow crossbill chicks to get an early start.
0:24:25 > 0:24:28The seeds, the pine kernels,
0:24:28 > 0:24:34are locked away inside the cones and early in the season when the cones are barely open,
0:24:34 > 0:24:39birds can't get at them. All, that is, except the crossbill.
0:24:39 > 0:24:41You've heard of cross-eyes.
0:24:41 > 0:24:44Well, this bird has cross-bills, hence the name.
0:24:44 > 0:24:46It's the only bird in the world
0:24:46 > 0:24:51with the upper and lower parts of its bill crossing over when the bill's closed.
0:24:51 > 0:24:56It's the perfect shape to prise open the woody scales of a pine cone
0:24:56 > 0:24:58and get at the seeds inside.
0:25:05 > 0:25:08It seems to behave more like a parrot than a songbird.
0:25:08 > 0:25:10With the scales prised apart,
0:25:10 > 0:25:14it uses its highly flexible tongue to pull out the seed.
0:25:27 > 0:25:30By adopting this breaking and entering technique,
0:25:30 > 0:25:33the crossbill opens a treasure chest of food,
0:25:33 > 0:25:38allowing it to bring up its young at what seems to be the worst time of year...
0:25:41 > 0:25:46..and be one step ahead of all the other birds in the wood.
0:25:50 > 0:25:57Winkling out pine kernels is one thing but eating the pine's needle-like leaves is quite another,
0:25:57 > 0:26:05yet surprisingly they provide the energy required for Mother Nature's variation on the Highland fling.
0:26:05 > 0:26:08TAPPING AND SQUAWKING
0:26:10 > 0:26:17Spring on the shores of Loch Garten in Speyside is marked by another unusual sound.
0:26:20 > 0:26:22It's the male capercaillie.
0:26:25 > 0:26:30He's strutting his stuff and calling to attract the ladies.
0:26:30 > 0:26:32They quite literally fall at his feet.
0:26:32 > 0:26:38TAPPING AND SQUAWKING
0:26:40 > 0:26:43In fact, we only hear part of the call.
0:26:43 > 0:26:47One component is so low-pitched, we can't hear it at all,
0:26:47 > 0:26:50but low frequency sounds travel well in the forest,
0:26:50 > 0:26:54attracting hen capercaillies from far and wide.
0:26:54 > 0:26:57Combined with his swaggering courtship dance,
0:26:57 > 0:27:03he cuts a fine figure, but he contributes virtually nothing to bringing up the brood.
0:27:04 > 0:27:08The capercaillie is one of the few creatures that can digest pine needles
0:27:08 > 0:27:11and as they're on the tree all year round,
0:27:11 > 0:27:14there's plenty of food for the female birds to feast on.
0:27:14 > 0:27:18They don't need the males. They can rear their young on their own.
0:27:34 > 0:27:38So, the males have nothing else to offer the self-sufficient females,
0:27:38 > 0:27:40but their courtship display.
0:27:40 > 0:27:44Oh, and the contribution to the genetic makeup of their offspring!
0:27:52 > 0:27:56And when the pine needles fall from the trees, they're not wasted.
0:27:56 > 0:28:00They don't break down quickly like broader leaves
0:28:00 > 0:28:03so they're used not as food, but as building materials.
0:28:06 > 0:28:10And the builders are ants
0:28:10 > 0:28:13- wood ants.
0:28:16 > 0:28:19This mound isn't an untidy heap of pine needles.
0:28:19 > 0:28:21There's order here.
0:28:22 > 0:28:28The needles are placed in such a way that rainwater is shed just like a thatched roof on a cottage.
0:28:32 > 0:28:37The side facing the sun is also slightly flattened to warm up the nest
0:28:37 > 0:28:44while workers block and unblock the nest entrances to control the temperature and humidity inside.
0:28:48 > 0:28:51They also sit on the top, sunbathing,
0:28:51 > 0:28:53not some sort of ant siesta,
0:28:53 > 0:28:57but a means of taking the sun's warmth down to the brood chambers
0:28:57 > 0:29:01deep inside the nest and warming up the young
0:29:01 > 0:29:05- miniature storage heaters on legs.
0:29:05 > 0:29:10The ants return the gift of building materials
0:29:10 > 0:29:13by protecting the pine trees from leaf-eating insects.
0:29:18 > 0:29:24Some caterpillars are able to digest the needles and could make a sorry state of the tree,
0:29:24 > 0:29:26but the wood ants come to the rescue.
0:29:32 > 0:29:34They kill the caterpillars
0:29:34 > 0:29:38and then carry their victims back to the nest.
0:29:38 > 0:29:42In fact, wood ants are so important at keeping pests at bay
0:29:42 > 0:29:46that they're key players in the preservation of these ancient pine forests.
0:29:49 > 0:29:52There are over 80 pockets remaining today,
0:29:52 > 0:29:57but at one time the forests were so thick and covered so much of Britain
0:29:57 > 0:30:01that a squirrel, if it had a mind to, could have scampered all the way
0:30:01 > 0:30:07from the north of Scotland to the south coast of England without ever having to touch the ground.
0:30:14 > 0:30:20It's hard to imagine that these manicured fields and patches of woodland
0:30:20 > 0:30:24were once covered by a vast unbroken forest.
0:30:38 > 0:30:44It was filled with game, including an animal that was hunted out of existence in this country.
0:30:44 > 0:30:49But after an absence of 300 years, it's back.
0:30:49 > 0:30:51It's the wild boar.
0:30:59 > 0:31:06It's escaped from farms and now it's set up home in woodlands in several parts of southern England,
0:31:06 > 0:31:10like the Kent and Sussex border and the Forest of Dean.
0:31:15 > 0:31:19In the wild, they feast on beech mast, when it's in season,
0:31:19 > 0:31:25and to make it, the beech tree has struck up an intimate relationship with another living thing.
0:31:30 > 0:31:37To find out what led me to a friendly encounter with some close relations of the wild boar.
0:31:41 > 0:31:45Pigs - they're quite keen on biscuits. Here you go.
0:31:45 > 0:31:48But they're even keener on something else
0:31:48 > 0:31:50and they're very good at finding it.
0:32:10 > 0:32:15Oh, look what she's found! Pigs will do anything for a piece of this.
0:32:15 > 0:32:21It's a summer truffle and pigs share their predilection for them with many a wealthy gastronome,
0:32:21 > 0:32:23but it's more than just a tasty titbit.
0:32:23 > 0:32:25It's a kind of fungus
0:32:25 > 0:32:31and beech trees rely completely on fungi like this for their survival.
0:32:31 > 0:32:36It's incredible that something so big can rely on something so small.
0:32:36 > 0:32:41If I asked you how trees manage to get hold of water and nutrients,
0:32:41 > 0:32:46you'd probably say through the roots but that's only a part of the story.
0:32:46 > 0:32:48They couldn't do it at all without these...
0:32:50 > 0:32:53..fungal strands.
0:32:53 > 0:32:59Mycelium, it's a kind of symbiosis. The fungus passes minerals and water to the tree
0:32:59 > 0:33:05and the tree, in return, passes sugars to the fungus, so they're both winners.
0:33:05 > 0:33:10So, down there in the soil, we have the real engine room of the forest
0:33:10 > 0:33:13and the amount of filaments, roots and rootlets -
0:33:13 > 0:33:19the intricate pipe work that joins it all together - is staggering.
0:33:19 > 0:33:22If you were to unravel the tree's roots,
0:33:22 > 0:33:26they'd stretch for five miles. Pretty impressive, eh?
0:33:26 > 0:33:30But if you were to unravel its fungal mycelium,
0:33:30 > 0:33:33that would stretch right round the globe!
0:33:33 > 0:33:37It means this beech woodland relies for its nutrients
0:33:37 > 0:33:41on a vast network of tiny underground fungal threads.
0:33:41 > 0:33:44So the next time you see a massive beech tree,
0:33:44 > 0:33:50just pause for a moment and reflect on the fact that it owes its entire existence
0:33:50 > 0:33:54to something as small as a summer truffle.
0:33:54 > 0:33:55There you go.
0:33:55 > 0:34:01In fact, without fungi, nothing in the forest would grow
0:34:01 > 0:34:05and although it's another part of the woodland that we don't tend to see,
0:34:05 > 0:34:11the total weight of fungi in the soil approaches that of the trees themselves.
0:34:11 > 0:34:15The only time we do see them is when they reproduce.
0:34:26 > 0:34:30Some rely on wind to carry their spores up into the air.
0:34:34 > 0:34:38The stinkhorn gives off a smell that attracts flies
0:34:38 > 0:34:41and they spread the spores far and wide.
0:34:44 > 0:34:51The ink cap releases them as the fungus decays into a black mushy soup.
0:34:59 > 0:35:03The bird's nest fungus forms the perfect cup.
0:35:15 > 0:35:19Raindrops falling into its centre splatter the spores
0:35:19 > 0:35:23so they bounce out of the cup and onto the ground.
0:35:26 > 0:35:30Raindrops trigger the puff in an earthstar's puffball
0:35:30 > 0:35:34to help release its cloud of tiny spores.
0:35:36 > 0:35:39And all these fruiting bodies
0:35:39 > 0:35:43provide an instant takeaway for woodland animals.
0:35:44 > 0:35:50Of course we like mushrooms too, and of the six thousand species in Britain, many are edible.
0:35:50 > 0:35:54A deadly few though are poisonous enough to kill us
0:35:54 > 0:35:59and they have an uncanny resemblance to the ones we like to eat.
0:35:59 > 0:36:04This is a true morel, a fungus found in woodland.
0:36:04 > 0:36:08This is the false morel.
0:36:08 > 0:36:13Now the true morel is edible and very tasty.
0:36:17 > 0:36:19But this one, when ingested in your stomach,
0:36:19 > 0:36:24produces a chemical that's found in rocket fuel.
0:36:24 > 0:36:28You will die a lingering and painful death.
0:36:30 > 0:36:31I've got the right one...
0:36:33 > 0:36:34..I think!
0:36:38 > 0:36:42The morels appear in late spring and early summer,
0:36:42 > 0:36:46but most mushrooms send up their fruiting bodies later in the year,
0:36:46 > 0:36:48when the atmosphere's warm and moist.
0:36:48 > 0:36:51They tell us that another change is in the air
0:36:51 > 0:36:55- the slow transition from summer into autumn.
0:37:00 > 0:37:04It's another time of woodland plenty.
0:37:06 > 0:37:11Trees spread not spores like fungi, but seeds,
0:37:11 > 0:37:15and they're often as not wrapped up in a sweet-tasting fruit or berry,
0:37:15 > 0:37:21a slowly ripening feast, not only for the palate but also for the eyes.
0:37:32 > 0:37:36There's something about the colour red that makes fruits and berries
0:37:36 > 0:37:40totally irresistible to woodland animals.
0:37:40 > 0:37:43It's one way a tree enlists help to spread its seeds.
0:37:45 > 0:37:49Birds provide a free courier service.
0:37:49 > 0:37:53The seeds hidden inside the berries aren't digested,
0:37:53 > 0:37:58so they pass through the bird's gut, only to be deposited some distance from the parent tree
0:37:58 > 0:38:04complete with a dollop of fertiliser to help kick-start their germination.
0:38:11 > 0:38:15So, berries and fruits are not only vital to the tree,
0:38:15 > 0:38:18but also to the rest of woodland life.
0:38:21 > 0:38:26These fruits could mean the difference between life and death for the dormouse,
0:38:26 > 0:38:30which must put on enough fat to survive the coming winter.
0:38:30 > 0:38:35And when it's run out of fruits, there are always nuts.
0:38:38 > 0:38:42With the trees producing so much food at this time of year,
0:38:42 > 0:38:46woodlands are a magnet not only for the fruit and nut eaters,
0:38:46 > 0:38:47especially the mice and voles,
0:38:47 > 0:38:51but also the animals that like to eat THEM
0:38:51 > 0:38:54and it's at night in a Somerset woodland
0:38:54 > 0:38:57that you'll find the feast is in full swing.
0:38:57 > 0:39:03This glut of food, though, means that the local rodent population goes into overdrive
0:39:03 > 0:39:07and one woodland resident can take full advantage of it.
0:39:10 > 0:39:15See if I can rustle one up and to do that, I'll need one of these,
0:39:15 > 0:39:18see if I can find the right track.
0:39:20 > 0:39:22HOOTING
0:39:22 > 0:39:24There we go.
0:39:24 > 0:39:26- HOOTING - An owl.
0:39:27 > 0:39:30Wait for it...
0:39:30 > 0:39:33- HOOTING - There we go, it works!
0:39:33 > 0:39:36OWL HOOTS
0:39:36 > 0:39:42As the evenings draw in, our forests ring to the well known call of our commonest owl, the tawny.
0:39:42 > 0:39:46It's only about at night and it's beautifully camouflaged,
0:39:46 > 0:39:49so although you hear it, you seldom see it.
0:39:51 > 0:39:52OWL HOOTS
0:39:52 > 0:39:58Now what you might not have realised is that this isn't one owl calling, it's two.
0:39:58 > 0:40:00OWL HOOTS
0:40:00 > 0:40:03It's a duet between male and female.
0:40:03 > 0:40:08The female is doing that rather shrill "k-wick"
0:40:08 > 0:40:13and the male is a much more sonorous "too-woo".
0:40:15 > 0:40:18The reason we notice them more in early autumn
0:40:18 > 0:40:21is that it's the time of a tawny owl teenage rebellion.
0:40:21 > 0:40:24The chicks' demand for food is unrelenting
0:40:24 > 0:40:30so after three months, the parents kick them out, which creates a serious real estate problem.
0:40:30 > 0:40:33Who-oo's going to live where?
0:40:34 > 0:40:38And that's where the calling comes in because a battle royal now ensues,
0:40:38 > 0:40:41certainly in terms of just calling each other names.
0:40:41 > 0:40:45All these youngsters are vying for their own territory,
0:40:45 > 0:40:49often to the consternation of the adults who already occupy it.
0:40:50 > 0:40:53The timing's critical.
0:40:53 > 0:40:56If there was little food around, the young owls would starve,
0:40:56 > 0:41:00but with so many fruits and nuts, the rodent population is at its peak,
0:41:00 > 0:41:03providing plenty of easy to catch meals,
0:41:03 > 0:41:11a life saver for a juvenile with limited hunting skills but bad news for dormice.
0:41:13 > 0:41:15SCREECHING
0:41:15 > 0:41:20The tawny owl has such good hearing, it can pick up the slightest rustle
0:41:20 > 0:41:26and home in on its target with pinpoint accuracy and all in the dark.
0:41:32 > 0:41:36Don't worry, our dormouse is safe.
0:41:36 > 0:41:40But a wood mouse isn't so lucky.
0:41:40 > 0:41:43The dormouse will live to scamper another day.
0:41:53 > 0:41:59Accuracy is also the hallmark of another group of nocturnal predators, the bats.
0:41:59 > 0:42:03HIGH-PITCHED CHATTERING
0:42:13 > 0:42:17Like owls, they rely on sound to hunt in the dark,
0:42:17 > 0:42:21but they also use sound to find their way about.
0:42:24 > 0:42:26It's called echolocation.
0:42:26 > 0:42:32They emit a sound and then listen for the returning echo.
0:42:32 > 0:42:34Now we can't hear it, it's so high pitched,
0:42:34 > 0:42:39but we can if I use this - a bat detector.
0:42:39 > 0:42:45This will lower the frequency and make it audible to us through this little speaker here.
0:42:45 > 0:42:52Different bats yell at different frequencies and I can adjust the frequency on here
0:42:52 > 0:42:55which'll then tell me which bat I'm listening to.
0:42:55 > 0:42:59RHYTHMIC BEATING
0:42:59 > 0:43:03Whoa! According to the frequency, that was a pipistrelle, a little tiny one.
0:43:03 > 0:43:07DEEPER RHYTHMIC BEATING
0:43:07 > 0:43:10That's Daubenton's bat.
0:43:10 > 0:43:13FAINT RHYTHMIC BEATING
0:43:15 > 0:43:17That was a serotine.
0:43:17 > 0:43:22This whole woodland is alive with the sound of bats yelling their heads off,
0:43:22 > 0:43:26but they're not calling to one another. They're sending out those noises
0:43:26 > 0:43:29and listening for the echoes coming back through the wood.
0:43:31 > 0:43:34With this echolocation system,
0:43:34 > 0:43:40a bat can lock onto moths flying in complete darkness with consummate ease,
0:43:40 > 0:43:45but one species of British bat specialises in catching other kinds of prey.
0:43:45 > 0:43:49You'd think that something like this spider here,
0:43:49 > 0:43:52tucked safely away in its silken web,
0:43:52 > 0:43:59would be safe from flying predators but then you'd have reckoned without a woodland specialist...
0:44:00 > 0:44:02Natterer's bat.
0:44:11 > 0:44:15This bat is what's known as a "gleaner".
0:44:15 > 0:44:18It plucks prey off the vegetation
0:44:18 > 0:44:22or in this case, a spider straight out of its web.
0:44:27 > 0:44:30On our journey around British woodlands,
0:44:30 > 0:44:33we've been to the Cairngorms and South Wales,
0:44:33 > 0:44:35to Oxfordshire and Devon,
0:44:35 > 0:44:39the New Forest and the Forest of Dean
0:44:39 > 0:44:43and we've seen all sorts of amazing plants and animals,
0:44:43 > 0:44:48but maybe there's something important that, so far, we've left out.
0:44:49 > 0:44:54There's one central silent player in this woodland drama,
0:44:54 > 0:44:58on whose yearly cycle all the other inhabitants depend...
0:44:58 > 0:45:01the tree.
0:45:01 > 0:45:05'It's the tree and the way it changes through the seasons
0:45:05 > 0:45:08'that determines the pace of woodland life'
0:45:08 > 0:45:15and it's the tree that provides nourishment and shelter for everything that lives here.
0:45:25 > 0:45:33The oranges, yellows and browns of autumn are its final extravagant flourish
0:45:33 > 0:45:36before its leaves die and fall to the ground.
0:46:07 > 0:46:13For our dormouse, the autumn change means his entire world is falling down about him,
0:46:13 > 0:46:17so with little to eat and nowhere to hide,
0:46:17 > 0:46:22he simply makes a winter nest in a convenient hollow and goes to sleep.
0:46:22 > 0:46:27His name, dormouse, means "sleepy mouse".
0:46:27 > 0:46:31He'll sleep now for up to six months
0:46:31 > 0:46:34and as long as he's well fed during the summer,
0:46:34 > 0:46:36he'll wake again in spring.
0:46:36 > 0:46:40If he hasn't, then it's a sleep from which he'll never wake.
0:46:49 > 0:46:53The trees themselves shut down during winter,
0:46:53 > 0:46:58but in this constantly changing environment lives an animal community,
0:46:58 > 0:47:03most of whom are active throughout the entire year.
0:47:16 > 0:47:18And what of the future?
0:47:18 > 0:47:21Well, the good news is that over the next 100 years or so,
0:47:21 > 0:47:27there are plans afoot to restore and enlarge our areas of broadleaf woodland
0:47:27 > 0:47:30so there will be more space for wildlife.
0:47:30 > 0:47:34Of all our habitats, woodland has the greatest variety
0:47:34 > 0:47:37and the largest number of plants and animals.
0:47:37 > 0:47:41They may be hard to spot, hidden away among the trees,
0:47:41 > 0:47:44but at least now that we know some of the places to look,
0:47:44 > 0:47:49that weekend walk in the woods should be all the more rewarding.
0:48:21 > 0:48:25Subtitles by Red Bee Media Ltd
0:48:25 > 0:48:28E-mail subtitling@bbc.co.uk