Children of the Sun - Butterflies

Elegant and graceful. Small but approachable. And infinitely varied and colourful. Butterflies never cease to fascinate and impress us. And yet these exquisite beings begin life as little more than worm-like creatures. Ever-hungry caterpillars that munch their way through our gardens. What is the secret behind their curious lifestyle? And why do they use their wings not just for flight, but as a canvas for some of the most striking patterns in nature? A garden shed. An unlikely place for butterflies. And yet it offers warmth and protection during the colder months. A red admiral has overwintered here and now stretches its wings as it wakes from a long sleep. It tries to head towards the light. At last, guided by the fresh air, it makes its escape. The buds of the blackthorn bush are about to open. But within its thorny branches, something else is breaking out of its cocoon. A small emperor moth. It climbs up the stem to pump up its wings. The feathery antennae indicate that it's a male. He will use them to pick up the scent of a mate. The larger cocoons are those of the females. They will emerge a few days later. The female has the same large eye spots as the male. But not the broad antennae. And at the end of her abdomen, a special gland emits an enticing perfume. It will attract males from several kilometers away. The small, brightly colored males waste little time. They have no mouthparts and can't feed, so they need to mate before their energy reserves run out. A peacock butterfly has no such problems. It can refuel at any time and has come to the blackthorn bush to feed on its sweet nectar. The female emperor moth will lay her eggs within hours of mating. Unlike the males, she only really becomes active at night. Under cover of darkness, she lays her eggs on a branch within the hawthorn, close to where she mated. Each month sees the arrival of new butterflies. The common brimstone has come to this wet woodland to breed. During the mating season, males defend territories against rivals. But in the excitement, innocent passers-by sometimes get caught in the crossfire. The female deposits her eggs on an older buckthorn bush. The unassuming tree is crucial to the survival of her caterpillars when they hatch. The older buckthorn is the sole food plant of brimstone caterpillars, so plant and butterfly often go hand in hand. After two weeks, the empty egg case is left behind. The caterpillar is already munching away on the leaves of its host plant and will increase its weight 2,000-fold over the next month. To avoid detection by predators, it often rests along the midrib of a leaf, where it's difficult to spot. But not all caterpillars are fussy eaters. Some have a more varied diet. The hatchlings of the vapora moth first consume the remains of their egg cases. Then they spin a silk thread and climb up to the nearest leaves. In this case, the leaves of a small birch tree. The vapora moth is widespread and common across Europe. Feeding on a great variety of plants, it can live in all kinds of habitats. One of the most widespread and successful plants is our common stinging nettle. The stinging leaves are in fact packed with nutrients. They contain more protein and minerals than most. And they are the perfect baby food for caterpillars. The caterpillars of the peacock butterfly feed together as a group, stripping off the leaves one at a time. There's safety in numbers and the squirming mass confuses predators. Rows of black spines also act as a deterrent. The caterpillars are being watched. The barred warbler has not been put off. She has too many hungry mouths to feed. A red admiral has also chosen a nettle to deposit her eggs. But she lays them singly, one at a time. It takes about ten days for the small caterpillar inside to develop. Once it has hatched, it spins a little tent around itself and begins to feast on the nettle's leaves. It might appear that plants have little defence against the tiny, chomping mouths. But recent research has revealed otherwise. Plants, it seems, can detect vibrations made by caterpillars feeding on neighbouring plants. They respond by producing defensive chemicals and stop an attack on their own leaves. After three to four weeks, the caterpillar is ready to pupate. It draws together the edges of a leaf and forms a tent around itself. Here, it will be safe from predators and can change into its adult form. Drawing fine silk threads from a special gland in its mouth, it glues the leaf together. Finally, the caterpillar sheds its skin one last time and turns into a pupa, or chrysalis. A small tortoiseshell caterpillar is also disappearing into its cocoon. Within a few hours, its case has hardened and turned into an exquisite sculpture with a metallic golden sheen. Barely two weeks later, and the pupil case splits open, releasing the perfectly formed adult butterfly. The insect's body still needs to harden in the air, and the feeding tube, which is split in two, must be zipped together. Like the admiral and peacock butterfly, the tortoiseshell depends on the nettles as food for its larvae. The stinging leaves are in fact a defence against grazing animals, but they make an ideal habitat for insects. The caterpillars can safely move between the spines, and there's little danger of being eaten by a grazer. Even agricultural crops attract their own kinds of butterflies. A field of cabbage appeals to one of our most common species, the cabbage white. The caterpillars are the bane of farmers everywhere, and can decimate entire fields. But where pesticides are not put to use, natural predators will soon come to their aid. Wasps need protein-rich insect food for their own larvae, so a juicy caterpillar makes a perfect meal. She bites into the plump body and sucks up its inner fluids. With a belly full of protein juice, she flies back to the nest. She is greeted by the other workers, and regurgitates the green caterpillar pulp to feed the larvae. Not everyone is happy to have wasps in their garden, but those who are can be assured they'll help control insect pests. Unlike their caterpillars, most butterflies are not fussy eaters, and will happily feed on a variety of garden flowers. The nectar-rich blossoms of the lilac tree are a magnet for all kinds of butterflies, like the European map, the painted lady butterfly, the red abel, a frequent visitor to our gardens. Hovering above a flower is the aptly named hummingbird hawkmoth. Its smaller cousin, the bee hawkmoth, flies in a similar way. But there is one hawkmoth that is after something sweeter than nectar. The death's head hawkmoth has picked up the alluring scent of honey. But getting past thousands of armed soldiers is no easy task. Astonishingly, the large moth simply walks into the hive, straight past the seemingly unconcerned bees. The cunning thief mimics the scent of the bees, tricking them into thinking it's one of their own. It's the perfect adaptation for a life of crime. And chemical camouflage is not its only tool. A short, thick feeding tube is useful for piercing the honeycomb to suck out the sugary liquid. And a thick skin helps in case you get caught. It protects against the punishing stings. The hawkmoth has mastered the perfect honey heist. The death's head hawkmoth is one of our largest moths, and also one of the craftiest. After three months of gorging on blackthorn leaves, the caterpillar of the emperor moth has become huge. Special salivary glands on its lower lip now produce fine strands of liquid silk, which dry and harden in the air. The caterpillar spins an intricate mesh of fibers around itself, entombing its body in a silken cocoon. It will stay inside this protective casing until the following spring. All across the countryside, in every bush and tree, the caterpillars of moths and butterflies are preparing to change into their adult forms. Some are transforming not just their own appearance, but that of their surroundings. Wispy white drapes cover the tree trunks and bushes. The larvae of the ermine moth are busy spinning. Underneath their shroud-like web, the small caterpillars can feed undisturbed. Only when they emerge do they run the gauntlet of hungry beaks. But it's not just birds that are after the small larvae. A parasitic wasp moves gingerly across the web. It uses its long egg-laying tube to probe for caterpillars underneath. If it finds one, it thrusts the pointed needle into the body and deposits an egg. When the eggs finally hatch, the wasp larvae will eat the caterpillars from the inside. The brimstone caterpillar has already undergone a remarkable transformation. It's one of nature's miracles. A worm-like caterpillar is turned into a delicate creature with wings. The ermine moths have also emerged from their ghostly webs. They now cover the trees in vast numbers, just as their caterpillars did some weeks ago. The white adults will only live a few weeks, just long enough to produce another generation of hungry caterpillars. Woodlands provide a home for many kinds of butterflies, but their favourite plants often grow in open clearings. The withered leaf on a honeysuckle is not all it seems. Hiding within is a small caterpillar that has spent the winter asleep in a leafy tent. Now it starts to move and emerges from its secret hideaway. All it wants to do is feed. Thorny spikes on head and body protect it from hungry birds. The caterpillar of the white admiral butterfly feeds solely on honeysuckle leaves. By the time the plant flowers, the caterpillar has eaten all it needs and is ready to undergo a transformation. Its new body has taken on a green metallic form. Hanging motionless from a leaf, it appears lifeless and is perfectly camouflaged. Two weeks later and the pupa has turned into a black, alien-looking creature. It's hard to imagine that from this will soon arise a thing of exquisite beauty. A white admiral butterfly. Many hungry beaks comb the leaf canopy for insect prey. Those that are not well camouflaged will end up as a meal. One caterpillar has come up with a most unusual ploy to avoid being eaten. The larva of the comma butterfly has a large white patch on its back. From above, it looks much like a bird dropping and most predators give it a wide berth. Others, like the ruby tiger moth, defend themselves with poisonous bristles. And the long hairdo, sported by the miller moth, is also an effective armor. Most predators dislike a fuzzy mouthful. Caterpillars with a furry coat, it seems, can go about their business undisturbed. It's not put off by a caterpillar's hairy back. A large ground beetle, the forest caterpillar hunter. And it has an insatiable appetite. With strong jaws and defensive armor of its own, it makes an easy meal of the hairy caterpillar. With so little light and warmth getting through the woodland canopy, flying insects like butterflies are drawn to the sunlit glades and clearings. It's also where they find an abundance of flowers rich in nectar. They're a haven for all kinds of butterflies. The green-veined white. And the large skipper. Painted ladies. And the lesser purple emperor. The woodland brown butterfly is a rare sight today. It needs sunny forest edges and clearings. For centuries, large grazers like horses kept woodland clearings short and open. They created a mosaic of different habitats perfect for butterflies. A sunlit forest canopy also attracts other wildlife. A black stork is raising its chicks in the fork of a tree. The nest seems to attract woodland butterflies. The stork droppings are rich in salts and minerals. Which the butterflies need to produce their own eggs. And it's not just storks that leave behind such valuable gifts. A fox den provides a regular supply of fresh manure. It may be less sweet-smelling than the woodland flowers. But it's just as nutritious in its own right. Forest tracks and rides offer sunny refuges within the closed canopy of pine plantations. Flooded with sunlight, they allow flowering grasses and shrubs to grow. And butterflies to make the most of their biggest asset. Their colourful wings. Butterflies come in a whole kaleidoscope of colours and striking patterns. But their true display is invisible to our eyes. Some of their colours extend into the ultraviolet spectrum. Which butterflies can detect, but we can't even imagine. Under ultraviolet light, the male brimstone has bright patches on the underside of his wings. And yet to our eyes, he appears a uniform yellow colour. But the brimstone pays a price for such a flashy signal. Birds can also see in the ultraviolet. And his display could attract unwanted attention. The lighter female takes no such risks and appears a dull brown under ultraviolet light. To avoid detection by hunters, the brimstone, like many butterflies, rests with his wings folded. Under ultraviolet light, many wing patterns look very different. But exactly how butterflies perceive these colours is likely to remain a mystery. A thick stand of nettles at the woodland edge provides good cover for caterpillars and the developing pupae. It's the birthing pool of many butterflies. Inside the chrysalis, the caterpillar's body is undergoing an extraordinary change. It's broken down into a nutrient-rich soup and reassembled to form the parts of a butterfly. It's one of nature's most remarkable events. The Alp Mountains form a natural barrier across Europe. But numerous migrating butterflies cross the high peaks every year. For other animals, the mountains are not a barrier, but a home. The alpine ibex, a wild mountain goat. A cave high up in the mountains is home to some unusual inhabitants. Tissue moths spend eight months of the year in the dark and damp. We still know very little about their lives. Each spring, they fly down the mountainside to breed in shrubs and bushes, where conditions are a little milder. But after the adults have hatched, they return to seek out the darkness of the cave again. On the lower slopes of the mountain, rich alpine meadows erupt in a colourful display of summer flowers. And with them come the bees and butterflies. It's a short season for the alpine residents, so they quickly get on with their business of feeding and breeding. With such an abundance of nectar, that poses little difficulty. Some parts of the alpine landscape have remained virtually unchanged for centuries. The small Apollo is a high-altitude specialist often found near mountain streams. It rarely flies, clinging to the vegetation to sit out cold and windy weather. When temperatures rise, the female comes to life, crawling about at the water's edge to deposit her eggs. The yellow saxifrage, which grows in abundance here, is the food of choice for her young. At these high altitudes, the summers are very short indeed, so the Apollo's larvae overwinter as eggs and continue their life cycle the following spring. Alpine meadows are among the richest habitats in Europe, teeming with insects and insect hunters. The warm, sunny slopes are a favourite with butterflies. Large, colourful swallowtails so spectacular they were once the target of butterfly collectors. The males use thermal currents rising from the slopes to lift themselves up into the canopy. From a high vantage point, they patrol back and forth in search of females and rival males. High above the treetops is their mating arena, and aerial chases serve to settle any disagreements. Other insects also make use of thermal currents to get some lift. The owlfly has an ungainly, lumbering flight and needs much energy to stay airborne. When the sun slips behind clouds, the effort is clearly too much. All insects are cold-blooded and need the sun to warm up their bodies to become active. So when the sun reappears, the owlfly spreads its wings to soak up the warmth. The owlfly is a curious mix between butterfly and dragonfly. But it doesn't feed on nectar. It's a hunter. The tall flower head simply serves as a take-off and landing pad. Wildflower meadows are a paradise for insects and butterflies. Hundreds of grasses and flowers offer an abundant supply of nectar. Not surprisingly, there are more butterflies to be found here than in any other habitat. But even in paradise, the sun doesn't always shine. A thunderstorm can bring gusty winds and large raindrops. For a butterfly, it's no trivial matter. They try to protect their delicate wings by folding them together. And when the storm has passed, they open them up and dry them in the sun. The marbled white butterfly was once a common sight in every dry grassland. The striking black and white checkered pattern makes it stand out from the crowd. But like most grassland species, it's now in decline. Meadow browns once danced over our grasslands in their hundreds and thousands. While others formed part of a rich and colourful community of life, fluttering in the summer breeze. In the last two decades, we've lost nearly half of our grassland butterflies. These magical creatures that have given us such delight may soon become a thing of the past. And their decline is largely the result of our own careless actions. Modern farming techniques have changed the face of our landscape. They've pushed aside much of our wildlife and the habitats they depend on. As wildflower meadows have disappeared, so have many of our butterflies. Vast swathes of crops now stretch across our countryside. They're devoid of food for butterflies. In patches of grassland bordering the fields, the struggle for survival continues. A wasp spider. And it's not just after wasps. A red admiral has been trapped in the sticky web. The spider tries to reach its victim for a lethal bite. Miraculous escape. The spider is left with just a fragment of wing. Spiders are a natural part of the ecosystem and don't threaten the survival of a species. Not even that of the false ringlet, a rare and endangered butterfly. For millions of years, the ringlet has lived in grassy bogs and marshes across Europe. Rarely straying from traditional sites. Now, the draining of wetlands and intensive farming of the land have triggered an alarming decline. But not all farming practices are harmful to wildlife. Traditionally managed grasslands have a richer diversity of plants and animals than those abandoned and left to their own devices. A wet lowland meadow carpeted in crimson flower heads. The blood-red blooms attract insect pollinators. And there is one which is dependent on the plant for its entire life cycle. The dusky large blue butterfly not only feeds on the nectar, but also mates on top of the flower head. It even lays its eggs right amongst the tightly packed blossoms. When the tiny larvae hatch, they quickly disappear inside the flower head. Here, the caterpillars feed on the unripe seeds and quickly take on the flower's crimson-red colour. After three weeks, the large maggots have consumed everything there is and need to find a new home. But trapped high above the ground, that's easier said than done. The only way down is to abseil. The resourceful caterpillar now spins a silken thread and attaches it to the blossom. Far below, the reception party is already waiting. Anchored to her thread, she begins her descent. The rope has snapped, but the thick moss softened the landing. The caterpillar now needs the help of an unlikely babysitter. A red ant is attracted to the scent of the pink grub. The caterpillar mimics the smell of the ant's own young, and in a case of mistaken identity, is carried back to the nest. The sneaky imposter will live among the ants for the next few months, and surreptitiously feed on their larvae. The following spring, it will emerge as an adult dusky blue butterfly. Grasslands that are mown later in the year, when the caterpillars have disappeared underground, ensure that the dusky large blue can breed. Without human intervention, the grasses would soon be smothered by larger shrubs and bushes. So the survival of this rare butterfly depends on the careful management of its habitat. A flock of migrating starlings has descended upon a plum tree. They are frenetic and messy feeders. The half-eaten fruit is soon set upon by decomposing fungi and bacteria. A red admiral is attracted to the fermenting plum. The sweet juice is a welcome energy drink before it sets off on its migration south. Summer is nearly over, but there is still plenty of food for insects, including butterflies. The sweet sugary sap oozing from the wound on a birch tree draws in a multitude of hungry creatures. And late summer has other things to offer. A buddleia bush has come into bloom with a spectacular display of lilac flowers. It's also called the butterfly bush for good reason. The fragrant blooms seem to be an irresistible lure. By this time of year, the wings of many are tattered and torn. These red admirals are unlikely to make the migration south again. A dark crimson underwing is also attracted to the buddleia. It could easily be mistaken for an admiral, but is in fact a rare moth. Many of us plant flowers in our gardens to attract butterflies. And even non-native plants will supply ample nectar. Michelmus daisies are native to North America, but happily cater to the needs of our own insects. This peacock butterfly requires fuel of a different kind. It flies on wind energy alone and is a particular favorite with children. Inside the warmth of the house, another less popular creature is bedding in. The larvae of the common clothes moth evolve to feed on the fur of dead animals. Not surprisingly, our woollen jumpers are a good substitute. By late autumn, most butterflies and moths have disappeared. But there is one that only makes an appearance now. The winter moth. Despite the increasingly chilly nights, the male is on the wing looking for a mate. A pheromone gland discharges perfume into the air. The strange wingless creature is a female winter moth. She climbs to the tip of a branch to deposit her eggs amongst the closed buds. The small white moth balls will remain here all winter. In spring, the young caterpillars will emerge, eating holes in the leaves and blossoms of fruit trees, often causing extensive damage. With the first fall of snow, even the winter moths die. Not so the common brimstone. Wrapped in snow and ice, it doesn't move. It's asleep, waiting for spring. The winter landscape is devoid of butterflies. Many have migrated south, others are dormant and asleep. But a few seek out warm spots in our homes and garden sheds. Red Admiral butterflies have started to overwinter with us and are one of our more adaptable species. But to continue seeing a colourful variety of butterflies in our meadows and gardens, we need to look after them all just a little more.