One force rules above all others, driving a daily rhythm to which all life must adapt. (GIBBONS HOOT) It turns rainforest trees into towering giants and others into stealthy killers. Strange creatures hide in its shadows,... while others bask in its life-giving energy. It is the awesome power of the tropical sun. Captions by Julie Taylor. Captions were made with the support of NZ On Air. www.able.co.nz Copyright Able 2021 (GIBBONS HOOT) The forest awaits its ruler. (HOOTING SPEEDS UP) Life here follows a daily rhythm millions of years in the making. (GIBBONS HOOT) A constant cycle driven by a celestial force. (HOOTING CONTINUES) Families of gibbons declare their ownership of the treetops by song. (FAST-PACED HOOTING) Sound travels furthest in the still, cool air of dawn. - (HOOTS) (HOOTING ECHOES) - The song of the gibbon heralds the most powerful force to rule these ancient rainforests. - (HOOTS) (LOW, ETHEREAL MUSIC) These islands stretch along the equator. The sun rises at the same time every day. Part of a timeless cycle. (ETHEREAL MUSIC, VOCALISING) - (HOOTS) - The plants and animals of the rainforest depend on this one force more than any other. The trees, subjects of the sun, need its energy to grow. Already, billions of leaves release water vapour as they trap its life-giving rays. The sun will grow ever more powerful as the day advances. Beneath the canopy, the early morning is a busy time. The sun's green realm is so complex that this young orangutan will spend nine years learning from his mother ` the longest childhood of any primate, other than ourselves. An important day of lessons is just getting started. (GENTLE, WHIMSICAL MUSIC) Orangutans are the most arboreal great apes. This newborn will spend his whole life in the treetops. (BRANCHES RUSTLE) (WHIMSICAL MUSIC CONTINUES) He'll need to learn how to navigate safely. She moves only one limb at a time. It gives her the balance to walk the trickiest of tightropes. Orangutans are unique amongst primates in the way they move between trees. Instead of jumping, she takes her time, using her weight to bridge gaps. (BRANCHES RUSTLE) In their years together, she'll teach him all about life beneath the sway of the sun,... for theirs is a complex world. One filled with giants. Here, a single family of trees dominates,... and it has for millions of years. The dipterocarps. (GIBBONS HOOT) There are hundreds of species, and in places, they make up 80% of the canopy. Like most trees, the fight for light begins in the forest's darkest depths. As morning wears on, sunlight penetrates the shadows,... but fleetingly. (ANIMALS, BIRDS CALL) Down here, plants have only minutes each day to extract what energy they can. Young dipterocarps play a waiting game. They can survive almost half a century, hardly growing,... waiting for a gap to open up in the canopy to give them their moment in the sun. (LOW, INTRIGUING MUSIC) The very tallest stretch over 90m into the sky. (GIBBONS HOOT) To outcompete other trees, they put more of their efforts into growing their enormous trunks. Dipterocarps are the tallest tropical trees on Earth, powered by competition for the mighty sun. The first branches only appear towards the very top, maximising the exposure of every leaf to the sun's energy. But to live in a forest of giant trees, animals require extraordinary adaptations. While hot-blooded mammals like the orangutans rise early, cold-blooded reptiles must wait for the warmth of the sun. This is the Draco lizard. He basks in the morning sun,... his dark skin helping absorb more of its energy. As he warms up, he switches his camouflage. But this time, it's too late. He's already been seen. Paradise tree snakes like to eat Draco lizards. Time for a speedy exit. The trouble is the crowns of the giant trees all stand at different heights. There can be huge gaps between them. It's easy to get cornered up here. But not for the Draco. He can fly to safety. Though the chase doesn't end there. In these forests, even snakes fly. (LEAVES RUSTLE) It takes something special to live amongst the giant dipterocarps. And not just for animals. Rainforest plants have evolved different ways to compete for the sun's energy. In the struggle for sunlight, one has become a stealthy killer. It begins life high amongst the dipterocarps branches. (LEAVES RUSTLE) But it needs more nutrients than can be found here. While most trees grow towards the light, this one reaches into the darkness. Its roots travel downwards 50m or more ` a journey that may take years. Right now, there's no obvious threat to the host. But once the roots penetrate the soil, everything changes. (DRAMATIC NOTE) Fuelled by water and nutrients from the ground, the roots thicken. The plant sends down more and more. Whatever they touch, they fuse together. By now, the dipterocarp's fate is sealed. It is in the grips of a strangler fig. (OMINOUS MUSIC) Over the years, the roots choke the host. Outcompeted and unable to grow, the giant is defeated. This will be its tomb. Decades later, a few shards of rotting wood are the only clues a huge tree once stood here. The strangler, supported by its own roots, stands over the dipterocarp's decaying remains,... a victor in the eternal struggle for the sun's energy. It now exploits its position in the canopy to reproduce. For this, it depends on a bizarre partnership. The strangler teams up with a miniscule wasp, one just 2mm long. Its flowers are locked away inside the figs,... with a single hole the only way in. This female fig wasp sacrifices her wings to enter. She'll never fly again, but, then, she'll never leave. As she lays her eggs in the flowers, the strangler seals the entrance shut. This is the final act of her life. She will die in here. The fig transforms as flowers and wasp eggs develop. Male wasps emerge first. He has no wings, for he will never leave. His life has two goals ` the first, to mate with his younger sisters. He bites his way in and inseminates them with his telescopic penis. Task one complete, he now digs an escape route. It's not for him, for he will soon die. Inside, his sisters now emerge. Already mated, they head for the exit. While they developed, so too did the fig's flowers. As they leave, they're brushed with pollen. They escape from the tunnels dug by their dead brothers. They'll live for two days. In that time, they must find another strangler ready to receive them. When they arrive, they enter to lay their eggs and, at the same time, pollinate the flowers. The cycle begins again. The strangler fig and the wasp depend entirely on each other, a bizarre partnership over 60 million years in the making. And in a remarkable twist, it turns the killer tree into a lifesaver. Because of the wasps' short life span, different figs fruit at different times, so the strangler may be the only fruiting tree for kilometres around. It draws in animals from across the forest. All who come to dine here will perform a vital service for the strangler ` to help spread its seed through the canopy. A single tree produces as many as 500,000 fruits. Yet so many animals visit the banquet that the tree can be stripped bare within a week. Making the most of this food source is a crucial lesson for any young orangutan. But this morning, the chance to feed is coming to an end. It's approaching midday. In the exposed high canopy, the temperature is already well over 30 degrees. The sun is beginning to overwhelm. (LOW, PULSING MUSIC) As it grows stronger, the trees risk losing too much water. They begin to shut down. Now directly overhead, the all-powerful sun beats down on the ancient rainforests. Its subjects must protect themselves from its might. All activity comes to a stop. The orangutans head down below the canopy to seek some respite. They retreat to their nests to wait out the heat. The day's lessons are on hold. Everyone needs to conserve their energy during these hours, including the area's biggest male. But, despite the conditions, one female is still up and about She's the only one here without a baby, and this is her chance to do something about it. In the midday heat and with a belly full of figs, he'll need some encouragement. Orangutans are largely solitary. Encounters like this are very rare. Try as she might, it really is just too hot. Right now, there's only one thing on his mind, and that's keeping cool. Something has to give. The sun draws up so much water that as afternoon arrives, clouds form. (RUMBLING) They build and build until they burst. (THUNDER RUMBLES) Over 10cm of rain can fall in just two hours,... much of it offered up by the trees this morning. One remarkable plant turns rainfall to its advantage. Gracilis is a carnivore, preying on insects. It lures victims with nectar offered on the underside of its lid. It's an easy meal for a hungry ant. But those who visit, risk their lives. There's enough grip to hang on, but only just. (PLOP!) (PLOP!) It takes one direct hit. (PLOP!) (PLOP!) (PLOP!) (PLOP!) There's no escape. The ant will slowly dissolve. Gracilis turns the downpours to its advantage. And, as they subside, others benefit too. She works hard to find the insects she likes to eat. It takes all her strength to rip open a fallen dipterocarp. But there are rich rewards inside. The afternoon rains lower the temperature, giving sun bears a chance to feed. But for others, all this water presents a unique challenge. As streams swell across the rainforest, a miniature world springs to life. In the late afternoon, male rock frogs begin to gather. They're here to compete for a mate. The trouble is, at 2cm long, it's not easy to get heard above a waterfall. (WATER RUSHES) - (CHIRPS) - So rock frogs vary the duration, pitch and volume of their calls. - (CHIRPS QUICKLY) - (CHIRPS SLOWLY) (CHIRPS QUICKLY) - A decent effort, but this much noise requires drastic action. By varying their calls and waving to each other, they've come up with a unique solution to life as a tiny frog in a very noisy world. The males are here in the hope of attracting a mate, though her arrival can push things over the edge. Despite a sophisticated means of communication, it quickly descends into a wrestling match. Species here have come up with all sorts of solutions to deal with the regular rains. It's part of an ancient daily pattern driven by the tropical sun. Over millions of years, its energy has created a realm like no other all because it rules with such extraordinary consistency. The islands stretch from Australia to Asia, along the equator. Day length changes by only minutes and temperature by just a few degrees. Some of these forests experience the least seasonal change of any habitat on Earth, which poses a unique problem. The trees have no predictable cues to time their breeding. Instead, they have to rely on infrequent droughts. It could be every few years or once a decade, but drought triggers the trees to reproduce. The dipterocarps lead the charge, each tree dropping thousands of winged seeds. - (GRUNTS) - For animals, it's one long feast. Bearded pigs grow fat on the oil-rich seeds. During the glut, most seeds are eaten or destroyed, but by dropping so many at once, the dipterocarp giants ensure at least some escape the pigs' hungry jaws. All animals have to take advantage of these unpredictable times of plenty. And it's not just the dipterocarps. Many trees here only bear fruit every few years. Orangutans need to learn where to find them and when to seek them out. The irregular supply of fruit is one reason the youngster spends so much time with his mum. a tree may only fruit once or twice in their nine years together, so he'll need to learn its location before he sets out on his own. It's a unique paradox of these rainforests that despite the abundance of life, there are long spells when fruit is scarce. Mother knows all too well that she can't rely on fruit alone to get by. Hidden in the treetops is a rich supply of ants and termites. You just need to know where to find them. To thrive in these forests is all about learning what to eat, where and when. Today's lessons will soon be over. (SOFT FLUTE MUSIC) The subjects of the sun must prepare for the coming night, for there is another realm here. It's one where creatures hide away from the sun's power and have evolved to live shrouded in darkness. The transition is marked by an extraordinary sound. (INSECTS CHIRP) Right on cue, the call of the 6 o'clock cicada. (CHIRPING CONTINUES) (CHIRPING CONTINUES) Night here is a shadowy sanctuary of freaks. Fungi glow with a soft light to lure insects that will disperse their spores. With just the light of the moon to see by, one denizen of the darkness undergoes a bizarre change. Deinopis. Her two large eyes are truly astonishing. Right now, they're changing. Cells inside them build to form an extremely light-sensitive membrane, essential to the way she hunts. Her web is unlike any other ` a Velcro-like net built to ensnare passing prey. Preparations complete, she waits. (DRAMATIC MUSIC) She binds her quarry in silk before slowly sucking the life from it. When dawn returns, the membrane inside her eyes will be reabsorbed, a feat she repeats night after night after night. The tangled roots of the strangler fig are home to another hunter. Each of the tarsier's sensitive eyes is the same size and weight as its brain ` so large they can't move. But the tarsier can rotate its head around 180 degrees. Its huge ears, however, are able to move independently. The tarsier is built to detect the slightest movement in the dark. (DARK, INTRIGUING MUSIC) Higher up in this world of shadows, an even more bizarre creature inhabits the rainforest canopy. Like the snake and Draco, the colugo's life is dictated by the giant trees. To avoid climbing up and down their trunks, it glides across the forest. The underside of its gliding membrane has no fur, which reduces drag. It's also as large as physically possible ` a cloak stretching from the shoulders to the tail and even between its fingertips. Gliding from tree to tree saves a lot of time as colugos search out young leaves and flowers. A freakish cast inhabits this world without sunlight, each with their own extraordinary adaptations. But they too must abide by the sun's rule. As dawn approaches, they retreat to the shadows. The colugo will depend on its mottled fur for camouflage. (GIBBONS HOOT IN DISTANCE) A distant call proclaims the coming day. (HOOTING CONTINUES) And, as it does at the same time, every morning here in the tropics, the sun returns to rule over the ancient rainforests. (LOW, ETHEREAL MUSIC, VOCALISING) - (HOOTS) - The islands between Australia and Asia are the biologically richest on Earth. Erupting volcanoes drive the evolution of the beautiful and bizarre. Along the shores and in the sea, the moon holds sway over a mysterious world. And in its forests, the sun's daily rule sustains an astonishing profusion of life. Nature's most powerful forces, the earth, sun and moon, make this a place like no other. Forged over millions of years, these ancient islands are home to the greatest assemblage of life on the planet. Captions by Julie Taylor. Captions were made with the support of NZ On Air. www.able.co.nz Copyright Able 2021