Amidst the gravel, roots and mud, a tragedy is unfolding that hardly anyone notices. A bicycle tyre is a rolling death trap for slow worms, newts and beetles. Creatures just a few centimetres long stand no chance against a speed of 25 km/h.
In the past, you had to watch your step when out walking. These days, you’re lucky if you spot anything crawling, hopping or slithering at all. The wilderness is growing quieter. Species are becoming fewer. And sometimes all you find is a flattened shadow on the path.
Here are six tiny inhabitants of our forests. Overlooked, run over, underestimated.
1 | Roman snail
The Slower-Paced One
It’s the complete opposite of us. Whilst we whizz along the trail at over 25 km/h, the Roman snail manages about 4.2 metres per hour. Not per minute. Per hour. That works out at around 0.004 km/h.
The Roman snail is Europe’s best-known land snail and can be found almost anywhere where it is warm and not too dry. It is remarkably sedentary. Once it has found a good spot, it is reluctant to leave it. Understandable: anyone who moves that slowly is better off planning any relocations well in advance.
Its shell is made of limestone and almost always spirals clockwise. Only about one in 20,000 snails has a left-handed shell. Such rarities are actually called “Snail Kings” and are considered something of a sensation among snail researchers. If the shell is damaged, the snail can repair it itself to a certain extent.
The Roman snail glides along a trail of mucus it produces itself. That may sound unpleasant, but it is a technical masterpiece. The slime acts simultaneously as a lubricant, shock absorber and adhesive. This enables the snail to crawl over sharp edges or climb vertical walls. A climbing expert in slow motion.
It eats algae, wilted plants and all sorts of greenery. It grinds up its food with a so-called radula – a rasp-like tongue with thousands of tiny teeth. Anyone who has ever spotted the characteristic scraping marks on a cucumber will recognise its handiwork.
In winter, the Roman snail goes into hibernation. It seals its shell with a calcareous lid and falls into a state of torpor. In spring, it opens the door again and carries on as if nothing had happened. It certainly has time. In the wild, Roman snails often live to be six to eight years old, and under ideal conditions even considerably longer. In human care, lifespans of 20 to 30 years have been documented.
Their love life is also remarkable. Vineyard snails are hermaphrodites, meaning they possess both male and female reproductive organs. Nevertheless, they need a partner. Before mating, they fire so-called ‘love darts’ – small calcareous needles designed to increase reproductive success.
They have plenty of enemies: hedgehogs, thrushes, crows, mice, beetles, spiders – and, sadly, bicycle tyres too. On damp forest paths or after a summer shower, Roman snails like to crawl across the trail. That is often where their journey ends abruptly. What for us is just a soft crack means, for the snail, the end of a life that may have been underway for a decade.
In Germany, the Roman snail is a protected species. In France, however, it traditionally ends up in the oven as escargot with herb butter. Hardly any other animal illustrates more clearly just how relative the concept of ‘valuable’ can be.
2 | Common ground beetle
The armoured Sprinter
It looks like a miniature tank, runs like a middle-distance sprinter and is one of the most important predators on the forest floor. In Central Europe, the term ‘ground beetle’ covers more than 500 species – ranging from dull black to a metallic sheen, like the famous golden ground beetle. They all have one thing in common: they are constantly on the move, scuttling across the ground in pursuit of prey.
Ground beetles rarely take to the air. Instead, they hunt on foot. Snails, caterpillars, earthworms, insect larvae – whatever they catch, they eat. Some species even crack snail shells with their powerful jaws. For gardeners, they are therefore free pest controllers.
Anyone who disturbs a ground beetle will experience its chemical defence mechanism. Many species spray foul-smelling digestive secretions. The famous bombardier beetle, a relative of ground beetles, even shoots its attackers with a hot, corrosive liquid. However, even the best chemical weapon is no match for mountain bike and gravel tyres.
During the day, many species hide under stones, dead wood or leaves; at night, they go hunting. The larvae live in the soil for two to three years, where they already lead a predatory lifestyle. As adult beetles, they can live for several years – provided they don’t encounter a tyre tread first.
Many ground beetles are now on the Red List. Sealed-off land, cleared forests and intensive farming are robbing them of their habitat. Yet they are exactly the kind of creatures conservationists love: silent hunters, tireless cleaners and indispensable helpers in the forest ecosystem.
3 | Ringed snake
The Mistaken One
Hardly any native snake deserves a better reputation than the smooth snake. Completely non-venomous, rare and strictly protected – and yet it is repeatedly killed. Its only ‘crime’: it bears a resemblance to the common viper. For some people, that is enough. They beat the smooth snake to death, mistaking it for a venomous snake or simply out of a hatred of snakes. A bitter outcome for both: the smooth snake and the common viper.
A closer look reveals the truth: the smooth snake has round pupils, a slender body and no continuous zigzag pattern on its back, as is typical of the common European adder. Instead, it has a pattern of dark spots and speckles. At a maximum length of 80 centimetres, it also remains significantly smaller and less conspicuous than many of its relatives.
It owes its name to a particular hunting technique. It wraps itself around larger prey and suffocates them. Its diet consists mainly of lizards, slow worms, shrews and voles. If necessary, it will also eat earthworms or insects.
The smooth snake loves the warmth. It basks on rocks, dry stone walls, forest paths and trails. And that is often its undoing. Instead of fleeing immediately when danger strikes, it relies on its perfect camouflage. This often works surprisingly well against foxes, polecats, martens, hedgehogs or birds of prey. But not so much against a mountain biker travelling at 25 km/h.
At night, in the rain or in intense heat, the smooth snake does just as we do: it retreats to its private quarters – cracks in walls, piles of stones or hiding places among tree roots. Its territory covers several hectares, which it often uses for years on end. These snakes are considered to be extremely sedentary. If a smooth snake is cornered, it will bite, but its small fangs usually leave nothing more than a few harmless scratches on humans.
The species was voted Reptile of the Year in 2013 and is now a strictly protected species. Its greatest enemy is not the buzzard in the sky, but the creeping destruction of its habitats. Dry stone walls are disappearing, hedgerows are being cleared, and fallow land is being built on.
A constrictor snake can live for up to 20 years – provided it does not fall victim to one of its two greatest threats beforehand: human prejudice or human speed.
4 | Hawkmoth caterpillar
The False Serpent
Anyone who comes across this caterpillar is sometimes startled for a moment. When in danger, it puffs out its front end, rears itself up and displays large eye-like markings. Suddenly, this harmless creature looks like a small snake. It’s a bluff that works surprisingly often.
The caterpillar belongs to the hawk-moth family, a group of spectacular moths. Some fly by day, others by night. There are around 20 species in Europe, including the famous death’s-head hawk-moth. Its name sounds like something out of a horror film, but in reality it is more of a cunning thief: with its long, powerful proboscis, it can tap into beehives and steal honey.
Even the caterpillars are impressive, let alone the fully-grown moths. Hawkmoths are regarded as the Formula 1 drivers of the insect world. Some species reach average speeds of over 50 kilometres per hour, with some measurements even significantly higher. Top speed: up to 100 km/h. Their wings beat up to 90 times per second. They hover motionless in front of a flower and sip nectar like a hummingbird – a feat that only a few insects can master.
Hawk moths have truly high-tech eyes for their nocturnal forays. Their so-called superposition eyes capture even the faintest moonlight, giving them astonishing night vision. Some species even have hearing organs that allow them to detect the ultrasonic calls of hunting bats. If danger arises, they swerve at lightning speed or go into a nosedive.
Caterpillars, on the other hand, lead a much more leisurely existence. They eat leaves, like to bask in the sun on warm paths, and often crawl out into the open along forest tracks or trails. That’s where their camouflage ends. The ‘snake’ trick works against birds, but not against a mountain biker travelling at 30 km/h.
Some species of hawk-moths migrate thousands of kilometres across Europe every year. They fly from Italy to Sweden, making them some of the greatest travellers in the insect world. The caterpillars, on the other hand, often manage only a few metres a day. Perhaps that is precisely their problem: if you live on the trail, you need to be faster than a studded tyre.
Service life: A few weeks as a butterfly, several months as a caterpillar.
5 | Yellow-bellied toad
The one with the skull-like gaze
The yellow-bellied toad looks as though a designer has crossed a frog with a warning sign. Viewed from above, it is a nondescript speckled grey-brown. From below, its belly glows in a garish yellow and black. These warning colours mean: Leave me alone – I taste awful.
When this little amphibian feels threatened, it displays its famous toad reflex. It arches its body, stretches its arms and legs upwards, and ostentatiously displays the warning colours on its belly and the soles of its feet. It’s an animal’s way of saying, ‘This far and no further!’. In fact, its skin secretes a toxic substance that thoroughly spoils the appetite of predators.
The yellow-bellied toad is a master of survival. Unlike many other amphibians, it does not favour idyllic forest ponds, but rather makes do with whatever is available: puddles, wheel tracks, water-filled ditches or newly formed pools. In the past, such habitats were created by floods and torrents. Today, this role is often taken on by construction machinery, gravel pits or forest tracks.
Their call doesn’t sound like a frog’s croak, but rather like the distant ringing of a small bell. That’s where their name comes from: toads don’t ‘call’, they ‘toad’. On warm spring nights, a pond full of yellow-bellied toads sounds like a poorly tuned bicycle bell orchestra rehearsal.
The animals grow to barely five centimetres in length, but can live to a surprisingly old age. Their tadpoles develop at record speed because their habitats often dry up again after just a few weeks. Speed is vital for survival.
Unfortunately, this is precisely the problem we face today. The yellow-bellied toad is one of the most endangered amphibians in Central Europe. Many of its habitats are disappearing because paths are being paved, puddles are being filled in and damp areas are being drained.
This little toad is particularly vulnerable on trails and forest tracks. It loves shallow pools of water in the ruts – exactly where mountain bikes and gravel bikes pass by. Measuring just a few centimetres in length, it stands no chance against a wide tyre.
Service life: up to 20 years.
The greatest danger: The loss of small bodies of water, road traffic – and anything that moves faster than she can hop.
6 | Tree frog
The acrobat in bright green
When children draw a frog, they usually draw a tree frog. Bright green, round as a ball, with big eyes – the European tree frog looks just like the Frog Prince himself. Except that this fairy-tale hero has now become a rare sight.
The tree frog is a master climber. Its toes end in tiny suction pads, which it uses to climb up reeds, window panes and even vertical glass. Where other frogs hop, it climbs. Where others would fall, it hangs upside down from the branches.
Its colour is no accident. This little acrobat can change it. On a green leaf, it glows emerald green; on tree bark, it turns darker or brownish. Camouflage is vital for survival, because whilst flies, beetles, mosquitoes and spiders are on its menu, it is often on the menu of other animals. Grass snakes, herons, storks, owls and corvids all prey on the little climber.
Its eyes are particularly impressive. In the dark, its pupils dilate so much that they almost fill the entire eye. This gives the tree frog astonishingly good night vision. Its brain is also larger in relation to its body size than that of many other frog species. Whether this makes it smarter is open to question. It is certainly clever enough to catch insects with its lightning-fast, sticky tongue. Movement is the trigger. Anything that doesn’t move might as well not exist for the tree frog.
It is famous above all for its voice. The males have a large vocal sac and can croak so loudly that their calls can be heard over a kilometre away. On warm spring nights, they turn entire ponds into amphibian opera houses. The warmer it gets, the more active they become: at five degrees, their heart beats just ten times a minute; at 21 degrees, it beats almost 70 times.
During the day, the tree frog is often well hidden in bushes, reeds or even in the treetops. At night, it goes hunting. It can only survive where wetlands, hedgerows and near-natural water bodies are preserved. Pesticides, land drainage, road traffic and habitat loss have caused its populations to decline dramatically in many regions.
For mountain bikers, the tree frog is rarely a typical victim on the trails. This is because it usually lives too high off the ground. However, when young frogs leave their pools in summer or when frogs migrate between habitats, they too are run over by tyres – silently, unnoticed and often far too soon.
Service life: up to 15 years.
Dimitri Lehner
Editor
