Earth’s Tropical Islands

Journey across the tropical island of Madagascar and explore the unique and incredible wildlife it has to offer – from its famed lemurs to chameleons.

As the oldest island on earth, life has had time to evolve, and there are now more unique plants and animals on Madagascar than any other island.

It was formed nearly 90 million years ago when a giant landmass split apart, and Madagascar was cast adrift from east Africa. Braving the 400-mile ocean crossing from Africa, the first castaways arrived on the arid west of the island, and were met with vast deserts.

Ring-tailed lemurs are the direct descendants of one of the very first mammals to arrive, and they are thriving despite the arid conditions. They spend up to eight hours a day foraging in the Spiny Forest. Their plant-based diet includes plants with caustic sap that would burn human skin.

When humans arrived on the west coast, they too faced the hostile desert, high temperatures and droughts that can last a year. In the village of Ampotaka, the people have learnt to use baobab trees to help them survive. The trees grow up to 30 metres high and stores vast quantities of water in their trunks. By hollowing out the inside of the trunk, the people create huge water tanks storing thousands of litres of water, which they can use when times are tough.

Tiny labord’s chameleons are unique to Madagascar and have the shortest lifespan of any land vertebrate – living for just four months. They time their hatching with the start of the rainy season when the going is good, and then the race is on for them to grow, mate and lay eggs before the dry season comes round once again.

One of the most dramatic places in Madagascar is known as the Grand Tsingy – 500 square miles of sharp limestone pinnacles sheltering small pockets of forest. To survive here, Decken’s sifakas must climb these shards of rock, sharp enough to shred human skin, and leap 30 feet between them.

A series of even higher peaks forms a mountainous spine running down the middle of Madagascar. Just a few thousand years ago, human settlers from Asia brought the skills to turn the steep mountainsides into rice paddies. By digging terraces into the slopes, even the steepest gradients can be farmed, producing more than a million tonnes of rice every year. But only if they can keep their crop safe from the devastating plagues of locusts in their billions.

Madagascar’s mountain range defines the islands’ climate. It blocks warm, wet air blown in off the Indian Ocean to the east, creating the arid deserts of the west. But keeping all this moisture to the eastern side of the island makes rainfall high there, and this creates bountiful rainforests.

Most of the island’s incredible wildlife can be found within these tropical rainforests, including tenrecs, Madagascar’s own unique version of a hedgehog. They give birth to more babies than any mammals – as many as 32 in a litter. The streaked tenrec rubs together modified spines on her back to make a squeaking noise to warn all her babies of danger.

The extraordinary pelican spider twangs the threads of an orb web spider to lure it into its giant jaws. The aye-aye is one of Madagascar’s weirdest creatures, found hunting for insect larvae at night. It uses it bizarre 9cm-long middle finger to tap tree branches for hollow bits, before scraping away the bark and deploying its super-sized finger to fish out the grubs.

Madagascar’s unique wildlife has slowly been evolving for millions of years, but since humans arrived the pace of change has been faster than many animals can cope with. As little as 20 per cent of the island’s original forest remains, and 95 per cent of lemurs are now threatened with extinction.

The greater bamboo lemur is a story of how efforts to protect Madagascar’s wildlife can save a species from being wiped out entirely. These lemurs were thought to have gone extinct, thanks to the clearance of the bamboo forests they rely on for food. The bamboo lemurs are now protected and in the last year, a record number of babies were born. Madagascar is at a critical point, but with the right efforts, there is some hope for its wildlife in the future.

In the heart of south east Asia lies the tropical island of Borneo. Twice the size of the British Isles, it is the third largest island on earth and home to possibly the greatest diversity of life of any island – from flying lizards sun bears to orangutans. Its huge variety of habitats, from bustling coral reefs and ancient jungles to towering mountains, has given rise to over 60,000 species of plants and animals – many found nowhere else on earth.

Borneo’s shoreline is fringed by a tangle of mangroves and flooded forests, home to an extraordinary creature – the proboscis monkey. Their unique pot bellies allow them to survive on the nutrient-poor leaves, but even so, they must continually search for the freshest shoots. This means the whole family must cross one of many rivers that cut through the forest – patrolled by giant crocodiles. It is a drama rarely seen.

The island of Borneo is surrounded by some of the richest coral reefs in the world – a single reef can support more species of coral than the entire Caribbean Sea! This remarkable abundance attracted seafaring nomads, the Bajau Laut, ‘people of the sea’. Over generations their bodies have transformed, making them the ultimate human divers – but they are having to adapt to the modern world – using ingenuity to turn plastic waste that washes up on the beach to their advantage.

Heading inland are ancient forests, home to giants – the dipterocarps. Towering up to 100 metres high, they are the tallest rainforest trees in the world. A single tree can hold a thousand different species, and this intense competition has driven many animals to evolve in wondrous ways – on this island reptiles can fly.

At night, this competition in the jungle intensifies as many of Borneo’s 180 species of frog call for a mate. The bigger the frog, the louder the call: a problem for one of the smallest frogs on the island. In this never-before-filmed sequence, a male tree-hole frog, barely larger than a thumbnail, has come up with an ingenious solution to being heard above the noise.

Compared to the abundance of life in the treetops, the forest floor is an impoverished world. With little to eat, many of Borneo’s terrestrial mammals are smaller than on the mainland – including the exceedingly rare Bornean sun bear. At just over 1m long, it is the smallest bear in the world. To survive, they have developed a surprising skill – they are expert climbers, able to climb higher than any other bear, to feed on honey and fruits high up in the canopy.

For those confined to the forest floor, more ingenious methods are required. The Penan are indigenous hunters that have lived in Borneo’s forests for over 4,000 years. They use a remarkable sign language, known as Oroo’, to communicate through the jungle. A long stick is adorned with intricately folded vegetation and shaped bark, to tell a complex story.

In the heart of the island, looming above the rainforest, lies another of Borneo’s diverse habitats – mountains. Their range runs over 500 miles through the centre of the island. At over 4,000 metres, Mount Kinabalu is one of the highest peaks in south east Asia. It rains here almost every day, the water washing away any goodness in the soil. To get the nutrients they need to survive, one group of plants have gone to extreme lengths, becoming carnivores. The modified leaves of pitcher plants form pitfall traps. Insects are lured to the trap’s edge with sweet nectar, before slipping into a lethal pool of digestive enzymes. Borneo holds the greatest collection of pitcher plants in the world, including one that is after something much bigger than insects. Nepenthes hemsleyana is a pitcher plant that has evolved to attract woolly bats. Its traps are perfectly adapted to provide a sheltered roost for the bat. In return the plant gains nutrition from the bats droppings, a remarkable relationship, only recently discovered.

Borneo’s intense rain has carved out vast cave systems through the island. Deer cave is so large you could fly a jumbo jet through it. They are home to millions of bats whose guano forms the basis of an entire ecosystem – sustaining some of the largest concentrations of cockroaches in the world, as well a wealth of other cave critters.
Thanks to the bats, even in this most extreme habitat, Borneo harbours an extraordinary array of life.

For 10,000 years, Borneo’s staggering diversity has been protected by its isolation, but with the arrival of industrial logging, all that has changed. Only half of its ancient forests are left, and much of its unique wildlife is under threat, including the iconic orangutan. Scientists are only just discovering the true scale of their intelligence – recently capturing footage of a mother orangutan using forest leaves to create an anti-inflammatory treatment for her aching joints. But with their forest home being destroyed, how much longer can these remarkable animals survive?

This is a journey across Hawaii’s varied islands, discovering how they were made and the incredible wildlife that thrives there.

Hawaii is the most remote island chain on earth, and its tropical shores are hard to reach. But for the hardy creatures that can make it here, like the waterfall-climbing fish, carnivorous caterpillar and Laysan albatross, a land of opportunity awaits. From newly formed lava fields to lush jungles and vibrant coral reefs, these diverse and beautiful islands have it all.

Packed with surprising stories, the hidden gems of this tropical paradise are uncovered using stunning photography. Dramatic footage of the humpback whale heat run – the biggest courtship battle in the world – and intimate views of the world’s oldest known bird feeding its chick are just some of the highlights of what Hawaii has to offer.

The islands are so isolated that it used to be that one new species arrived every 100,000 years, but the arrival of people has radically changed the face of Hawaii. Now it gains around 20 new species every year. The remarkable Jackson’s chameleon is one of the animals recently introduced. Showing off its voracious appetite, the programme reveals how it is eating its way through the native animals and contributing to wiping them out entirely.

But this is a place where people are looking to the future and attempting to bring wildlife back from the brink of extinction. White terns, once extinct on the main islands of Hawaii, have gone from a single pair to over 2,000 birds in the last 60 years. It is a huge challenge, but people are seeking progressive new ways to live alongside nature to allow Hawaii’s wildlife to continue to thrive.