What looks like a complete miracle sometimes turns out to be a simple natural phenomenon. Over the course of evolution, more than 1,200 species of animals have developed the ability to walk on water, from tiny insects and spiders to reptiles, birds and even mammals.
In the photo: helmeted basilisk; nationalgeographic
Ants have never been known to swim, but recent research shows that many of them are surprisingly adept in water environments. Among the 35 species of tropical ants studied, more than half showed high results in a kind of “swimming”, confidently staying on the water surface. This skill allows them to deftly escape from predators without sinking to the bottom. Such observations were published in an issue of the journal Modern Biology.
Photo: full-hd-wallpaper
Walking on water is not magic at all: physics can explain this phenomenon. Tiny animals can easily glide across the water surface due to the fact that their weight is supported by surface tension - the force that arises when water molecules “cling” to each other.
“Surface tension is a property that occurs when air and water come into contact, creating a trampoline effect on the surface,” explains John Bush, a professor at MIT who studies fluid dynamics.
Water striders
Photo: vokrugsveta.ru
There are about 340 species of water striders - insects that spend most of their lives moving along the water surface. They belong to the group of so-called gliders (gliders) - creatures capable of moving on water. Among their “colleagues” are fishing spiders and geckos.
By pressing on the water with its weightless legs, the water strider creates micro-depressions on its surface without piercing the top layer through. The impulses of the resulting tension set the insect in motion in small jolts. By alternately moving pairs of legs, the water strider glides through the water. Her measured steps create a trail of barely noticeable whirlpools that help her movement. The limbs of this elegant insect are covered with a layer of water-repellent hairs, which provides additional unsinkability.
Fishing spiders
Photo: Corbis
Fishing spiders live along the river banks of North America - quite large creatures that can eat a minnow or a small frog. These arthropods mainly feed on insects, hunting through the water column. The fisherman stays afloat thanks to water-repellent hairs covering his paws.
The fishing spider has several styles of movement through water: during leisurely walks, it is likened to a water strider, and when chasing prey or escaping from predators, its step turns into a real gallop.
“When running, spiders alternate pairs of their legs, pushing off from the surface with each of them in turn. Thus, they literally throw themselves into the air, springing on the water,” says biology professor Robert Suter of Vassar College.
Among other things, these creatures are able to swim like a sailboat: catching the wind with their legs raised up, the spiders allow its breezes to pick them up and easily push them forward along the surface of the water. According to Professor Suter, this style of locomotion could allow spiders to travel long distances with little or no energy expenditure.
Dwarf geckos
The fragile Brazilian dwarf gecko, measuring about 4 cm in size, would seem capable of drowning in the smallest puddle. However, during the course of evolution, this lizard has acquired several tricks that allow it to remain safe in the rain forests that are its habitat.
Since the size of this reptile is very small, it can easily move through the water like water striders and fishing spiders. In addition, the gecko has water-repellent skin, which prevents the body from breaking the surface tension of the water.
Basilisk lizard
Basilisks, arboreal lizards of Central America, are popularly nicknamed “Jesus Christ Lizard” for their ability to walk on water. When frightened, basilisks can run on their hind limbs along the surface of a reservoir up to 4.5 meters.
The weight of basilisk lizards does not allow them to glide through the water in a calm state, so scientists classify them as “strikers” - animals forced to move intensely in order to stay afloat. The “impact” technique consists of rapidly striking a series of steps onto the water surface, breaking through the surface tension and receiving a response push. The impulse from each push is maintained for enough time for the next step, while the lizards have to make enormous efforts to stabilize their vertical position.
Western American grebe
West American grebes are birds that spend most of their time in bodies of water. Nature has endowed them with powerful legs and short wings, which create not very convenient conditions for a land-based lifestyle. The breathtakingly beautiful and complex ritual of courtship of these birds is called nothing more than a “rush”: the male and female synchronously turn around, make a rapid dash forward, rise sharply above the water and, with the furious flapping of their wings, “run” along the surface of the reservoir, moving over it. feet.
Moving in this way over distances of up to 9 meters, grebes take about 22 steps per second. The fingers of these birds do not have webs - their structure resembles small oars, which helps to level the position of the body when moving through the water.
Dolphins
Photo: hqoboi.com
Even such large animals as dolphins can “walk” through the water from time to time. Whale and Dolphin Conservation Society spokesman Mike Bossley has been studying the behavior of these mammals in an Australian port for 25 years. He recently announced the existence of such a phenomenon as “tail walking.” By vigorously slapping the water with their tail, dolphins are able to assume a vertical body position above its surface and thus move forward. During such a movement, only the tip of the tail remains immersed in water.
Dolphins successfully learn the trick of walking on their tail in captivity, but in free waters this phenomenon turns out to be quite rare. One day Bossley saw a female dolphin “walking” on her tail. Subsequently, all the local dolphins joined her, adopting her technique. Scientists find it difficult to name the probable reasons for such walking. It is quite possible that dolphins are simply having fun in this way, having fun.
No one can repeat the miraculous walk of Christ on water, except perhaps some representatives of the animal world... What forces help them?
Perhaps the most famous water runner is water strider bug. Almost all their lives, water striders glide along the surface of reservoirs in search of prey; only for the winter they move to land and hide in moss or under the bark of an old stump. But what is the secret of runners? Firstly, thanks to its low weight and size. Secondly, the entire body of the insect is covered with water-repellent fats, which do not allow the water strider to get wet. And thirdly, the thick-haired cover helps the bug stay afloat, especially on the tips of the legs, which have direct contact with water - up to 16 thousand hairs can grow in one square millimeter. The fur gets wet over time, and if it is not straightened and dried in time, the bug will instantly sink to the bottom.
Feels great on the surface of the water spinning beetle. The beetle's hind legs have been transformed into blades to increase running speed and maneuver sharply. Especially during the mating period, the spinners perform complex pirouettes and twists - the males, picking up speed, make a sharp turn under acute angle and slowly, like dudes in a cool car, they swim past the females, the latter responding with curls and spirals.
Fishing spiders also have a similar technique. A huge number of fibers on the insect’s body, covered with a fatty water-repellent layer, and very little weight allow spiders to easily glide across the surface of the water. Like water striders, spiders stay on the surface on three legs and a pair of legs serve as “oars.”
More can run on water major representatives fauna like lizards, birds and dolphins.
Basilisks live near the shores of reservoirs, hiding in bushes and trees, but in case of danger, he resorts to his amazing ability - to run on water. It stays on the surface of the water thanks to frequent and short splashes. Contact with water lasts only 0.068 seconds. With each swing, the membranes between the toes capture a small amount of air, forming a special cushion that prevents the paw from getting wet. For this miraculous ability, basilisks are called “lizards of Jesus Christ.”
It is easier for birds to run on water than for lizards, since their wings create lifting traction, and the rapid movement of their wide legs helps. Very often, the water runway is chosen by those birds that move slowly and clumsily on land.
I want to continue it a little, i.e. tell not only about the water strider, how it runs on water, but also about which of the inhabitants of wildlife can also walk on water and why. Denis Zelenov, 10 years old, helped me carry out the experiments. Physics in nature- an interesting perspective.
What helps a porcupine float on the surface of the water?
It is safe to say about the porcupine that even if it wants to, it cannot drown, since the cavities inside its numerous quills are filled with air. This helps the animal float on the surface of the water.
As can be seen from the experiment: a green rubber ball does not sink when inflated, but a pink ball filled with air floats. So does the porcupine. This, of course, cannot be called walking on water, but rather swimming.
What helps birds stay afloat?
We have seen swans and ducks swimming on the lakes many times. They stay afloat easily.
This is because their feathers are hollow and they fit very tightly together, creating a layer of air. Bird feathers also have a lubricant that protects them from getting wet. Their body produces fat. With the help of its beak, the bird constantly lubricates its plumage with fat, which repels water. Water cannot wet the feathers, which helps the bird retain heat and float on the water.
This can be easily verified by the following experiment: take two balls of thread and dip one of them in vegetable oil. Then we put them in glasses of water and see that the oiled ball of thread floats, and the second one drowns.
Waterfowl also “run” across the water when taking off. This is how they manage to develop greater speed. Quickly moving their paws and simultaneously working their wings, they accelerate until they gain enough speed to take off. Then they push off with all their might from the surface of the water and take off. It's like an airplane taking off.
What keeps the water strider beetle afloat?
The water strider feels very free on the surface of the water, remaining afloat. Her paws are covered with thousands of tiny hairs that do not get wet.
If you look closely, you can see that where her thin long legs come into contact with the surface of the water, small dents appear in the water. The surface of the water behaves as if it were covered with a thin rubber film, which stretches under the weight of the beetle, but does not break. The water responds with pressure from the inside out, trying to restore its even surface. This phenomenon is called surface tension of water. It can be observed on a spoon filled with water to the brim - the water on the spoon is like a “slide”, which is clearly seen from experience. A drop of water in a state of flight, in zero gravity, retains its spherical shape only due to the force of surface tension. It is also called the “skin” of water.
We can observe the presence of force on the surface of water in the following experiment: let’s place a metal sewing needle or paper clip on the water. They, like the water strider, will be held on its surface.
These experiments show that the force of surface tension of water helps the water strider stay on the water. The weight of the insect is balanced by surface tension, the strength of which exceeds the body weight of the water strider. Thanks to this, the water strider stays afloat and can jump up into the air like a person jumping on a trampoline. Thus, water striders have two types of gait: jumping up into the air and sliding along the water. Many of us have watched how deftly water strider bugs glide through the water! Their speed of movement is up to 100 km/h. How do they do it? Scientists have proven that water striders use their limbs like oars. Only they don’t put their “oars” in the water. The paws form holes on the surface of the water. These pits work like the blade of an oar. Each stroke creates a mini-whirlpool behind the paws, turbulence in the water. Thanks to this, the water strider moves forward, as if pushing off from the back “wall of the recess,” as shown in the figure.
Simplified model of a water strider's foot
How does a basilisk lizard run on water?
The helmeted basilisk lives in Central America. It weighs about 100 grams. The basilisk is a rare creature that runs on water at a speed of up to 12 km/hour, i.e. twice as fast as a human. Frequent strikes with its paws help the lizard stay on the water and run across it. In this case, holes with walls appear in the water. These walls, with rapidly repeated impacts, behave as if they were solid in the short period of time between two adjacent impacts. When the lizard pushes the water down and back with its foot, the water responds with the same force, pushing it up and forward. Pushing off, the lizard runs through the water as if it were dry land.
How does a fishing spider walk on water?
The most skillful swimmer is the Pisaurid, a fishing spider. Can glide on water, just like a water strider does. Can stand up on its hind legs in the water and run like a basilisk lizard! But the most quick way The spider's movements are sailing. When the wind blows, the spider waves its front legs, or raises its entire body and allows the wind to drag it through the water, like a sailboat. Even a slight push of the wind can carry it across the entire pond.
As it turns out, very few creatures are able to walk on water.
It turned out to be an interesting day. Today you learned how physics works in nature. I hope you found it interesting. And if you liked The Fun Science, then please accept a gift from me. Collection exciting experiments, experiments and tricks with water.
Our list today includes amazing representatives of the animal world that can move on water:
1. Basilisk Lizard
The Basilisk lizard, also known as the Jesus Christ lizard, hides from predators by falling from the top of a tree and running along the surface of a pond located under the tree. They can run about 4.5 meters, reaching an impressive speed of one and a half meters per second.
The long toes on the hind legs of these lizards are webbed together, so by quickly slapping their hind legs through the water, they create air pockets that prevent them from going under water, as long as they maintain their speed. When they do go underwater, they can swim. However, they prefer to run on water to avoid the risk of being eaten by aquatic creatures.
2. Brazilian Pygmy Geckos
This tiny little one is not just adorable, she is also talented. Thanks to its light weight and water-repellent skin, the gecko can easily walk on the surface of the water. Because the gecko is so tiny (they are smaller in size than many of the insects that live in tropical forests Amazon), he risks drowning even in the smallest puddle - scientists believe that this is precisely why their ability to walk on water developed.
3. Water striders 
Water striders belong to the family of water striders, distinguished by their ability to walk on water. They are able to do this thanks to water-repellent legs, which help increase tension on the surface of the water, distributing the insect's body weight equally across all of its legs. Their movements also help them move through water. They push off with the middle pair of legs, making circular movements similar to the movements of oars, and glide forward through the water.
4. Fishing Spiders
Huntsman spiders, also known as dolomedes, are semi-aquatic insects that live near bodies of water where they hunt. They wait on the shore of a body of water until they notice ripples in the water and then run through the water to catch prey. Water also helps them avoid predators, as they can hide just below the surface by enveloping their bodies in tiny bubbles. Although most huntsman spiders feed on insects, more large species They can also feed on small fish, tadpoles and frogs.
Like geckos, huntsman spiders can move through water due to their light weight and abundance of short, water-repellent body hairs. Sometimes they swim through the water, putting several legs up so that the wind carries them in the right direction. Their short hairs also allow bubbles to form around their body when they hide below the surface of the water. In fact, they are so buoyant that they have to grab onto something while underwater, otherwise the water will push them to the surface, completely dry. Some types of hunting spiders can stay under water for half an hour.
5. Dolphins
Given that they have no legs, it is difficult to say that dolphins “walk” on water, but they are famous for their ability to dance above the waves using their tail fins. Unlike other animals, which use their ability to walk on water as an evolutionary advantage, scientists say dolphins do it purely for pleasure - for them it's the equivalent of human dancing.
Interestingly, although dolphins can “walk” with their tails, they almost never do this in wildlife. Exceptions are cases when a dolphin who was previously in captivity and undergoing training joined a group of wild dolphins.
6. Western and Clark's Grebes
Both the Western American grebe and Clark's grebe have a unique and beautiful mating ritual called “the rush,” which involves a pair of birds running across the water. Birds rush forward with their whole body and stand on their paws on the water, simultaneously flapping their wings. The pair then runs through the water in unison for a distance of approximately 9 meters, making 22 paw strikes per second.
These birds spend almost their entire lives in water. They have short wings and strong legs, which are not very convenient for walking on land, but are indispensable for the mating ritual.
7. Storm petrel
Unlike other animals on this list, this bird does not walk on the surface of the water, although that is exactly the impression it gives. In fact, it hovers near the surface of the water and lowers its paws into it, grabbing prey. The bird's legs are too weak to support its weight for more than a few steps. Because of this, it seems that she can walk longer on water than on land.
8. Heron on a hippopotamus
Herons really can't walk on water, but the bird in this video looks like it can do it - until a hippo emerges above the surface of the water, showing us what the heron's secret really is. She, of course, cannot walk on water, but she got as close to this as possible.
There are a huge number of amazing creatures living in the world. Some live in the sky, others on the ground, and still others prefer water. However, there are those who skillfully combine all three elements at the same time. water strider And this is exactly what we will talk about in our article.
Water strider insect: why was the little bug called that?
"Water strider" is the name of a beetle, familiar to Russian speaking countries. Our ancestors came up with this name by looking at the way the insect glides through water. They got the impression that with its movements it seemed to be measuring water. Moreover, this name became so attached to the beetle that even today it is still called. Although in English language his name sounds like water strider, which means “running on water.”
General information about the species
It should be noted that this is a very common insect. The water strider lives almost everywhere, with the possible exception of the cold lands of the Arctic and Antarctic. Scientists classify these creatures as members of the family of hemiptera, a suborder of bedbugs. Today, more than 700 species of water striders are known, which differ not only in appearance and size, but also in their habitual way of life.
Appearance and distinctive features
So, what does a water strider look like? The insect, the photo of which looks more like a floating stick, has a rather long, elongated body. Depending on the subspecies, its size can range from 1-2 cm to 4-5 mm. At the same time, the insect that lives in the sea is considered the smallest.
The main feature of any water strider is its long legs. Often their size exceeds the body of the bug itself. Such proportions are due to the fact that the paws are the key to the survival of the species. After all, they are the ones that allow the insect to quickly glide across the water strider. In total, the water strider has six limbs. She also has wings, but she uses them quite rarely.
Most representatives of this species are painted in dull colors. The most common colors are brown and black. By the way, this color is not accidental - nature specially awarded it to the insect. The water strider is almost always found in open space, so dark colors that blend perfectly with the water are its only chance to protect itself from constantly hungry birds and amphibians.
Ability to run on waves
The water strider is an insect whose description always boils down to a story about its amazing ability to withstand the water element. So how does she manage not to drown? The thing is that the bedbug's legs are covered with a special substance that resembles fat in its structure. This creates a kind of barrier that prevents the limbs from submerging in the water.
In addition, the insect knows how to correctly distribute weight: the load does not fall on one point, but is evenly transferred to all six limbs. As for the high speed of movement, it is achieved through fast, impulse strokes. It is they who create turbulence behind the water strider, which pushes it forward.
It is noteworthy that the bug can swim both on mirror-smooth surfaces and among waves. It is this skill that allows water striders to settle on various types reservoirs, which significantly increases their survival rate, and consequently the population.
Diet
Do not think that this is a peaceful insect; the water strider is a real predator. She boldly attacks any small creature that is unlucky enough to find itself on the surface of the water. Such impudence is completely justified, since other insects are not able to fight back, being in an element alien to them.
The hunting principle of water striders is very simple. As soon as the prey falls into the water, they swim up to it with lightning speed and cling to the body with hook-shaped front legs. Then the predator pierces the prey's shell using a sharp proboscis located on the head. Afterwards, the water strider can only suck the liquid from the body of the unfortunate creature.
Features of behavior of water striders
Many people mistakenly assume that this is an exclusively aquatic insect. The water strider indeed spends most of its life in the pond, but this does not mean that it is not capable of conquering other elements. For example, she has wings that allow her to make short flights. She uses them if her native reservoir begins to dry up and she needs to find a new shelter.
These bugs can also crawl on the ground. They do this very ineptly, since their thin legs constantly get stuck in small cracks and breaks. However, despite this, land is vital for them. The thing is that water striders cannot spend the winter in water, and therefore look for a warm home in the ground or in a tree. Thus, this one is truly unique, because it managed to conquer three elements at once.
Natural enemies
The main enemies of water striders are birds and amphibians. The former catch insects in calm sunny weather, while the latter skillfully track them at the edge of the shore. Naturally, they cannot cause much harm to the population, but individual individuals will clearly have to come to terms with a sad fate.
