A lost cat may never return, but as many adventurous cat owners attest, they rarely fail to come home. With advanced navigation abilities, hypersensitive senses and crystal clear memories, cats can find their way home even in unfamiliar places. Returning back is often only a matter of time - eventually, much loses its novelty, and the cat remembers that there is no place like home. How can cats navigate so accurately without any external tools?
Natural data of cats
We still don't know exactly what makes cats such skilled explorers, but they are top-notch at it. Humans have approximately 5 million odor-sensing nerve endings in the nose. Impressive, right? But not when you are a cat, because it has 19 million of these receptors. Using only scent, a cat can find a way out of many situations.
When your cat rubs against something, it's probably because she's happy or because she's giving the item her scent. The presence of scent on an object signals to other cats that the object belongs to him. This also allows the cat to recognize its own scent, so it can easily find the object in the future just by sniffing it. Leaving its scent throughout its territory, your cat can find its home by smell over short distances and not get lost.
Tips to make sure you don't lose your cat
If you know your cat has a tendency to roam, keep her indoors whenever you're outside the house, including when you go to work.
Take your cat for a walk using a leash or harness. Cats need regular exercise and fresh air to maintain their health and well-being. So even if your cat is an indoor cat, it's nice to take her outside for a walk every now and then.
Follow a routine for feeding your cat and bringing it into the house. Cats are intelligent creatures, so when darkness falls, they will remember to come inside. When it comes to food, you know your cat will always be ready to eat, especially if her favorite food is waiting in her dish.
Spayed or neutered cats are much less likely to wander far. When your cat has no desire to find a mate, she won't wander off your property as much. If you do not plan to allow your cat to have kittens or breed, you should have her spayed or neutered as soon as possible.
Cat navigation
Navigation research by scientists continues, and it is possible that cats, like birds, are naturally able to detect the Earth's gravitational field. This would give them a sense of direction even without appropriate visual cues. Birds need this when flying. It is possible that cats also have this skill, but to a lesser extent than birds.
People rely on visual cues. Cats also use landmarks to navigate, although their extremely high level of spatial intelligence adds a new dimension to this ability. Cats are experts at locomotion and remembering how to move based on the position of their bodies in relation to various objects. The paths our cats take through the neighborhood can seem incredibly confusing, and yet they follow them the same way every time, weaving through the branches of that particular bush and jumping between those particular fence posts.
Record distances
The usual travel limit for cats is about 600-800 meters from home, according to www.sunhome.ru. However, the Persian koto Sugar made a record-breaking journey. Shagur lived with his owners in California until they moved to Oklahoma. During the move, the cat disappeared. The owners decided that the cat jumped out of the back seat of the car during another refueling at a gas station. They discovered his absence only a few hours later, so they did not return and look for Sugar.
14 months after moving to Oklahoma, the cat finally found its owners. He climbed into the kitchen through the open window. How Sugar discovered his owners’ new home in an unfamiliar place is not clear, especially considering that he had never been to Oklahoma.
Magnetic attraction
The Earth is covered in magnetic fields, invisible forces that repel and attract each other depending on whether they are positively or negatively charged. Magnetic fields originate deep in the planet's core and radiate out to the surface, where they are influenced by tides and other magnetic forces from space. Every place on the planet has its own unique magnetic signature, based on the strength of the field at a given moment in time and space. We humans may need a special tool to detect this, but many animals can find magnetic north using just their mind and body. Among these animals are cats.
Many scientists believe that magnetic compounds are connected to the cat's central nervous system, which uses them to create a sixth sense: magnetoreception. Magnetic connections point toward magnetic north, but they can also detect field strength information in any direction. Magnetoception is not just a compass, it is a full-fledged GPS system. It's not known for sure whether cats can sense magnetic fields, but if they can, it might help explain why they are such skilled navigators.
Research by scientists
Researchers in Germany conducted a series of experiments to determine how developed a sense of orientation is in cats. At the first stage, animals were transported around the city in closed boxes and then released. They easily found their way to the house. After which the scientists complicated the task and took the cats out of town, where they placed them in a labyrinth where the animals had 24 exits, located in the cardinal directions. From above, the labyrinth was closed from light from entering, i.e. It was impossible for animals to navigate the sky. The cats were let inside, where they tried to find the right exit. What was surprising was that 98% of the animals chose the exit in the direction in which their house was located.
US scientists repeated this experiment. Before this, the cats were euthanized. However, this did not stop the animals from finding their way home, reports ruscats.ru.
In the course of such experiments, scientists came to the conclusion that the iron particles that make up the tissues of cats give them the properties of a kind of compass that reacts to the Earth’s magnetic field, thereby allowing the animal to return to the point of departure.
After a magnet was attached to the cat’s body, it ceased to be well oriented and began to get confused in choosing a road, which confirmed the data obtained.
When cats can't get home
Although it is common knowledge that cats are excellent navigators, this is not true for every individual cat. Some cats have trouble simply finding their way around the house, let alone navigating the outside world. This is especially true for domestic cats. An indoor cat that gets lost will not know in advance how to return to its territory, or how to avoid the dangers that await it on its way home.
Outdoor cats tend to be much better at finding their way home due to experience. A cat that is let out for a walk is an expert in how to get home. Wildcats in particular tend to have exceptional homing skills when needed. They are truly experts at crossing their territories to find food and shelter, and any cat that cannot do this will not live long enough to continue its breed. Thus, breeding in the wild occurs between the most experienced feline trackers, who then pass on their talents and knowledge to the next generation.
Moving to a new home
When you move into a new home, your cat may be confused, upset, or unhappy about being in a new environment, even if you are there with her favorite blanket, cat food, and lots of love.
Cats have been known to return to their homes. These intelligent creatures of habit have managed to walk many kilometers over rough terrain in difficult weather conditions to get to the home they know and love.
When you move into a new home, there are some steps you need to take to ensure your cat connects to your new home and knows that this is her place.
When you arrive at your new home, leave the kitten or cat at home for a week if possible. Don't let your cat roam outside, otherwise it might escape. Keep windows closed and be careful when entering and exiting.
Let your cat roam around your new home and get used to its new surroundings. Make sure your cat has his things, including toys and bedding. He will recognize his things, smell them and gradually realize that he is home.
© shutterstock
After a week, you can let your cat outside for a short time. Keep a close eye on your cat to make sure she doesn't wander too far into the unknown. Soon your cat will forget about her old neighbors and move on to a new life.
A wonderful homecoming
In April of this year, the world was surprised by the story of Pero, a four-year-old working shepherd dog. Perot managed to find a way from Cockermouth in Cumbria back to his former home, which is located on the coast of Wales. This true-life story is reminiscent of the movie Lassie Comes Home. Perot was able to run about 385 km over two weeks. It is noteworthy that the microchip that was on the dog confirmed that this was not an accident, and the young shepherd had indeed found its way to its first home.
Stories like this often attract the attention of the media, whose readers puzzle over how animals can travel. Although there are rumors that the dog was simply dropped off on his native farm, such stories prove the wonderful nature of animal instincts. The friendly relationship between people and dogs becomes the reason that we want to believe in some kind of magic of this ability. The question arises: does this ability to navigate exist only because of the close bond between the dog and its owner, or is there some scientific explanation for such a phenomenon?
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How to prevent cats from escaping
Cat owners don't like it when their pets disappear for a long time and they think about how to prevent frequent disappearances of their pets. In most cases, escapes are associated with the instinct of procreation.
There are two ways to stop the festivities:
- Use of hormonal oral contraceptives. The suspension or tablets are used according to the scheme to disrupt estrus, prevent it, or suppress sexual arousal in cats. The disadvantage is that the drugs must be given constantly, during the period of increased sexual desire. Hormonal drugs have side effects ranging from symmetrical baldness on the sides to the formation of tumors of the reproductive organs.
- Castration: Removal of the gonads before pets have sexual experience prevents sexual arousal and estrus. Consequently, there are no reasons for prolonged disappearance from home. The disadvantage is that it is necessary to switch to ready-made food for sterilized cats, otherwise the pets will become obese.
Rule or exception?
It is important to remember, however, that dogs and other animals that travel great distances are the exception rather than the rule. For every amazing story about cats and dogs traveling a long way to get home, there are many cases where animals get lost. For these pets, even a deep connection with a person was not enough to facilitate long-distance returns.
Thus, it can be assumed that there are some fundamental biological processes that help even domesticated species to move over long distances. But scientists still cannot determine exactly which of these processes allows dogs to return home.
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CHAPTER 7Finding the way home
When a man first went to sea, not to fish, but on a long journey, he stayed close to the shore. The Vikings first sailed to England, sticking to the shores of the North Sea; only later, when they had acquired the necessary knowledge of the movements of the sun and stars, were they able to cross the Atlantic and colonize Iceland and Greenland. These voyages were a great manifestation of the art of conscious navigation, but the long journeys which some animals make, guided only by instinct, suggest almost greater perfection of navigational powers.
Navigation includes two independent processes. The first is orientation, i.e. determining the direction in which to move; however, knowing just the direction is unlikely to help unless you first determine your location at the beginning of the journey. Determining your starting location is the second very important part of navigation. Orientation is relatively simple. Once upon a time, sailors navigated only by the stars, and later - with the help of a compass; but if they did not know the exact location of the final destination of the journey and the place from which they set off, they could not choose the right course. It is equally important to determine the location of the vessel while sailing. Wind and sea currents push the ship to the side, so it is necessary to constantly adjust its course.
Accurate determination of the ship's location became possible later, when two special devices were invented: a sextant, which measures the angle between the sun or any star and the horizon, and a chronometer, i.e. an accurate watch. Using these two devices, it is possible to calculate where the ship is, using tables that indicate the angular altitude of the sun and stars at certain times. This basic method is still used by navigators today, whether they are aboard a cargo ship or aboard the Apollo spacecraft. There is now growing evidence that animals navigate in the same way - be it ants finding their way to their anthill or Arctic terns traveling around the world - from the lakes of Ellesmere Island, 1,500 kilometers from the North Pole to Antarctic pack ice.
An ant that finds its way to an anthill does not perform navigation in the strict sense of the word, but rather orientation. He records in memory the position of the anthill not in space, but only in relation to the sun. If an ant moving away from an anthill sees the sun on the left at a right angle to the direction of its movement, then on the way back it should see the sun at the same angle on the right. Let's move the ant hurrying home 50 m to the right; it will move on the same course and end its path 50 m to the right of the anthill. The ant blindly follows the directions of its “compass”.
The navigational abilities of many animals have been studied using this type of movement. These experiments have gone a long way towards understanding the relatively simple problem of orientation, but it is much more difficult to figure out how animals determine their location. It is assumed that in the brains of animals that migrate (for example, migratory birds that return to their nesting sites year after year), there must be some equivalent of a sextant, a chronometer, and tables.
Theories that explain the nature of these internal biological mechanisms are inevitably approximate. This is explained by the difficulty of conducting experiments, since observing animals and studying their behavior during long journeys is extremely difficult.
Each of us has the opportunity to observe an ant in the garden or in the forest returning to its anthill, but it is more convenient to conduct experiments with bees. They can be easily trained to fly to a bowl of syrup, which can be moved from place to place. You can also move the hive; In this way, scientists are able to study the bee's orientation at the beginning and end of its journey. Simple observations have shown that insects maintain the direction of their movement using a kind of “solar compass”; It was also possible to clarify some of the features of the operation of this compass, although our understanding of it cannot be complete until we fully understand the physiological mechanisms of the functioning of the compound eye of insects.
The previous chapter described Frisch's experiments on the color vision of insects. They represent only a small part of his extensive research into bee behavior. The most remarkable results obtained by Frisch include his discovery of the “language” of bees. Frisch was able to figure out how bees find their way home from the flower plantations where they feed, and how they tell their fellow bees in which direction and at what distance from the hive the food is located. The amazing features of the “waggling dance” of bees, with the help of which this information is transmitted, have been described repeatedly. We omit them because in this case we are more interested in how an individual bee finds its way home, and not in how it communicates with its friends. Let us only note that the returning bee dances on vertically standing honeycombs, making a figure-eight figure with her dance, and the angle between the transverse axis of the figure eight and the vertical indicates the direction to the source of nectar in relation to the sun. Early in his observations, Frisch discovered that waggle dance performers gave incorrect information and became disoriented when the entire sky became covered with clouds; however, as soon as even a tiny piece of blue sky appeared, the bees immediately found the right path. This observation helped to understand what properties the “solar beacon” has. The bees could not use direct sunlight; this means that the information had to come from a piece of blue sky. As it turns out, bees navigate using polarized light.
As far as we know, no vertebrate sees polarized light.
Thus, the bee is another example of an animal living in a very special world, different from ours: after all, the bee has information that we cannot use. Polarized light is not a “species” of ordinary light, like ultraviolet, which can be thought of as light that has a different wavelength (“color”) than anything we can see. In a beam of polarized light, the light waves are arranged in a special way. Typically, light waves are represented schematically as in FIG. 4 shows sound waves. This is a very simplified diagram, since it shows vibrations occurring in only one plane - in the plane of the drawing; in fact, in a light beam, waves oscillate in all planes (Fig. 23). Polarized light differs from ordinary light in that it oscillates only in one plane, so it can easily be represented in the form of a primitive circuit shown in Fig. 4. It is very simple to imagine the phenomenon of polarization: imagine that you are standing on the seashore, and the waves are moving strictly perpendicular to the shore line. These waves can be compared to light waves coming from some source located in the sea; they are polarized because they propagate only in the horizontal plane along the surface of the sea. Unpolarized light can be thought of as many waves, also coming straight towards you, but these waves will propagate in different planes, inclined at all sorts of angles to the horizontal plane. Fig.
23 Unpolarized light waves (left) oscillate at right angles to the direction of light propagation, and these vibrations occur in all planes (both in the plane of the page and in any other) passing through the direction of propagation of light. Polarized light waves (right) oscillate in only one plane (in this figure, the plane of the page)
Light can become polarized by scattering as it passes through layers of tiny particles; When, for example, sunlight passes through the atmosphere, it is scattered by the molecules of various substances in the air. The direction of the plane of polarization depends on the angle of incidence of light on the particle, so the plane of polarization of light coming from different points in the sky depends on the position of these points relative to the sun. Bees see a characteristic pattern in the sky due to this difference in the polarization angles of light. From a very small part of this pattern, which is visible in the breaks in the clouds, they can probably determine the location of the sun and plot the correct course for home or to a flower bed.
The bee's eye has some physiological mechanisms with the help of which it perceives the position of the plane of polarization of light. It is possible that each rhabdomerus is particularly sensitive to light polarized in one specific plane; in this case, eight rhabdomeres of one ommatidium can respond to light polarized in different planes, and each ommatidium can perceive the overall polarization pattern of sunlight. However, all this is mainly speculation, and we will apparently have to wait for a full explanation until electrophysiologists finally take the time to study the complex eye of insects and its work.
It has now been established that some insects, as well as their “relatives”, such as daphnia, orient themselves using polarized light. Two Italian scientists studied the behavior of amphipods. These small, shrimp-like animals can be found by turning over a pile of rotting seaweed on the seashore; the amphipods immediately jump out of it and rush to the water. When the sand dries out, amphipods move closer to the sea, where the sand is wetter. It would seem that it could be simpler: amphipods move towards greater humidity or simply see the sea and head towards it. But when the amphipods were transferred from Rimini to Gombo, that is, from the east coast of Italy to the west, and released there on the shore, the crustaceans rushed towards land. Therefore, the amphipods did not pay any attention to the information coming from the sea, but were guided by the instructions of some “permanent beacon.” This “constant beacon” turned out to be the sun; more detailed studies have shown that amphipods can navigate using polarized light.
Wherever amphipods from the Rimini area are caught, they will always rush east - in the direction where, according to their “calculations”, the sea is under normal conditions. If you move amphipods to some other place, it may turn out that there will be land to the east of them, and then moving east will lead to their death, but nature does not take into account such unforeseen circumstances as human experiments. In the Rimini area, the behavior of amphipods follows a very simple pattern, which helps them survive under constantly changing external conditions. Amphipods behave the same way in Gombo, Brighton and Miami, their solar compasses adjusted to suit local conditions. As we will see later, some animals that have similar physiological mechanisms of orientation use other characteristic features of the external environment as a “beacon”. There are also animals that, if knocked off course, can correct the direction of their movement and find the right path to home. This is real navigation.
A fixed direction of movement is characteristic only of those animals that have a definite goal that does not change its position. For amphipods in the Rimini area, the position of the coast never changes, and movement in a once and for all established direction certainly leads them to a safe place. Other animals, on the contrary, have to find their way to shelter, which can be located in any direction from them. A fixed course relative to some reference point, such as the sun, will not help here; You must first accurately determine the location of the shelter, and then move towards it.
Small bugs live in swampy places that have no common name; in Latin they are called Stenus.
If such a bug is thrown into the middle of a puddle, it will immediately rush to the shore, to a safe place.
At the same time, Stenus
uses one of the most amazing methods of movement: it moves like a toy camphor boat.
Many insects float on water using its surface tension, and for Stenus
it also serves as a driving force. It secretes a liquid which, like camphor, weakens the surface tension of the water behind it; as a result, a force acts on it, moving it forward, and it quickly slides along the surface of the puddle. Returning to shore is not a blind rush in a random direction. The bug rushes to the nearest shore, which it recognizes by contrast, since the dark color of the shore clearly stands out against the background of the bright sky. You can trick the bugs by hanging a square piece of black board in the water. The bugs will not be directed towards the shore, but towards this board, since its upper edge forms a clear boundary between light and darkness.
Small turtles that have just hatched from eggs also rush to the brightest part of the sky, no matter which side it is located on. Like amphipods, they need to find a way to the sea. Female turtles lay their eggs in the sand well above high tide, so the newly hatched turtles have to find their way to the water. At first glance, it seems that this is very simple, but turtles, like amphipods, face their own problems. From the level of a turtle's eye, the sea may not be visible, the shore may rise up and only then gently descend to the water, and yet small turtles, having climbed out of their sandy nests, unerringly rush to the sea and, if necessary, overcome even such obstacles as like the trunks of fallen trees. Little turtles need to hurry, as many enemies lie in wait for them; in addition, if they fail to quickly get to the water, the scorching rays of the tropical sun will dry them out and they will die.
Experiments with the movement of turtles gave completely different results than experiments with Italian amphipods. No matter where the turtles were taken from, they always headed to the shore and then to the sea. It remains to be assumed that the turtles do not navigate by some permanent beacon, such as the sun, but use information coming from the sea. Having discovered this, the researchers conducted various experiments with the turtles: they put colored glasses on them or placed various obstacles on their way to the water. As a result, it was possible to establish that turtles hatched from eggs are directed towards the brightest part of the horizon. Even if the sky is covered with clouds, even if there are sand dunes or fallen trees on the way to the sea, the horizon above the sea is still much brighter than in other places. Moreover, in this case, the turtle's orientation is carried out according to the taxis type (see page 17): it compares the intensities of light entering both its eyes and changes the direction of movement until these intensities become the same; at this moment, the turtle's head is looking towards the brightest part of the horizon and, therefore, the seashore is directly in front of it. This may explain why turtles do not head towards the moon when it is above the mainland near the horizon. No matter how bright the moon is, it provides only a faint light compared to the glow of the open horizon. However, sometimes turtles head towards land. This usually happens in cloudy weather, when the sky is visible on the landward side through breaks in dense clouds, causing the turtles to become disoriented; but this very fact proves that when choosing a path they are guided by the brightness of the sky.
The path to the sea is only a small part of the turtles' journey. Having reached the water, they go to their underwater “pastures”, sometimes located thousands of kilometers away. Subsequently, they will return to this shore to continue their family, and during their lives they will return to the same place many times. This is not just orientation, but true navigation, since turtles need to know exactly where they are in the wide-spread “pastures” in order to be able to plot a course to their native shores; In addition, on the way they need to take into account the presence of currents that carry them to the side. It is usually believed that in this case turtles orient themselves by the sun. However, now that we are moving on to consider navigation in animals, we will leave turtles and turn to birds, whose migrations have been studied much more thoroughly.
Twice they brought me cuckoo chicks, believing that their adoptive parents had abandoned them. Most likely, the foster parents simply flew off to get food for the voracious chicks, but I had no choice but to take the chicks and feed them at home. The cuckoo chicks were kept in indoor aviaries and fed by hand, but when the time came for the flight, they showed great anxiety and rushed many times onto the southern wall of the aviary, and if they were released, they flew away towards the south. Apparently they had an irresistible desire to fly away and instinctively knew which way they should go. The results of ingenious experiments in which the direction of the sun's rays was changed using mirrors showed that birds orient themselves by the sun. The bird was placed in a round cage with windows. Mirrors were attached to the windows, the rotation of which changed the direction of the sun's rays, so that it seemed to the bird that the sun was shining from the other side. With each rotation of the mirrors, the bird turned in the cage in accordance with the location of the imaginary “sun” [2]. A happy accident once helped to obtain accurate evidence of the ability of birds to navigate by the sun. J. Matthews, an authority on avian navigation, conducted experiments with mallards. Normally mallards released into the wild would head northwest, but this time they were released shortly after the sun set in the southwest. As the mallards took to the air, the red glow of sunset appeared through a break in the clouds to the northwest. The ducks mistook it for the setting sun and flew to the northeast instead of northwest. Such situations must be rare, but birds have been known to be thrown off course by pink glows over distant cities.
Like amphipods, mallards always fly in the same direction no matter where they are released. This simple orientation plays an important role in the lives of animals. During the Antarctic spring, when the ground is nevertheless covered with snow and the sea is frozen to a depth of about a meter, small black specks can sometimes be seen slowly sliding across the ice. As they get closer, they take on a more and more definite shape. These are penguins that return to their nesting sites after winter feeding at the edge of the pack ice. Each year, penguins return in groups to their traditional nesting sites, with each penguin returning to the nest it occupied the year before. During the short summer, when the chicks grow up, adult birds make several trips to the sea for food for their offspring, and later migrate there for the whole winter.
Penguins appear to have highly developed orientation and navigation abilities and are also easier to study than mallards. Having no wings, they just waddle through the snow and ice at a speed of 6...8 km/h. Their blue-black backs stand out well against the background of dazzling white snow, and the tracks they leave are easily distinguishable. All this makes them a convenient object for research. That is why J. Emlen and R. Pennu visited American Antarctic stations, where they could catch penguins at their nesting sites and then release them in the vast expanses of snow, which have no special signs. Each penguin that was released in an unfamiliar place first looked around, then set off across the snowy plain. His route was plotted on the map at certain intervals until he finally disappeared over the horizon. When the sun was visible, the penguin walked straight, but if clouds rolled in, it immediately found itself in great difficulty and began to wander aimlessly in different directions. As soon as the sky cleared, the penguin immediately returned to its original course. A very important observation was made in these experiments: all penguins studied were heading north-northeast relative to a north-south line through their nesting site. (It should be recalled that near the South Pole, the north-northeast direction changes as you move around the pole, since no matter where you go from the South Pole, the path will always be due north.) The penguins were released in groups in five areas of Antarctica, in including at the South Pole and among the pack ice many kilometers from the earth. In all cases, the penguins set off in the same direction, which could never lead them home.
The choice of this seemingly meaningless direction is explained by the same reasons that cause migratory birds in captivity to turn in the direction they would fly if they were released. The penguins set off in the same direction in which they usually make their winter trips to the sea located in the north. In Antarctica, any journey to the north leads to the sea, so the direction chosen by the penguins is quite consistent with common sense: it is not entirely clear why the penguins move further east. The fact is that off the coast of Antarctica there are sea currents that are always directed to the west. It is generally accepted that during their travels penguins deviate to the east exactly as much as necessary so that sea currents do not carry them too far from their native shores over the winter.
The navigational abilities of penguins are manifested not only in their ability to find their way to the sea and back to their colonies. In winter, penguins apparently swim far into the open sea in search of food. In order to plot an accurate, rather than approximate, course to their nesting grounds in the spring, penguins must somehow accurately determine their location. Other birds traveling long distances must also be able to maintain the correct course and adjust to the wind if it blows them sideways. Small birds such as redstarts and pied flycatchers, which migrate from Scandinavia to Spain and Portugal, were sometimes blown across the North Sea by headwinds to the east coast of England. When the birds took flight again, their path was tracked using radar. It turned out that they were flying south-south-east from England (i.e. in the direction that should have led them to their original goal), rather than following their previous direction to the south-south-west, where they would have been lost in expanses of the Atlantic Ocean.
How birds determine their location can only be guessed at. The problem of deciphering the physiological mechanisms equivalent to the compass, sextant and map seems to us almost insoluble; however, based on some features of the brain and sensory organs of birds, it is possible to theoretically imagine certain orientation mechanisms. It can be expected that any theory based on well-established facts that explains the behavior of birds without any contradictions will eventually turn out to be correct and, in time, physiological mechanisms corresponding to it will be found. This “reverse” method of finding out the truth is quite widespread in various fields of science. For example, the existence and location of the planet Neptune was predicted based on observations of the planet Uranus, and later, when a new planet was discovered with the help of a telescope in the corresponding part of the sky, this prediction was confirmed. Theoretical considerations told astronomers where to look for the planet. Likewise, theoretical understanding of the physiological mechanism by which birds determine their location should tell physiologists what to look for in the brains and sensory organs of birds.
A theory explaining the navigational abilities of birds was proposed by Prof.
Matthews. Not all ornithologists accepted it, and Matthews himself, no doubt, will make appropriate amendments to it as soon as new facts become available to him. However, this theory gives a good idea of the extremely rich capabilities of birds' vision and the almost supernatural ability of their brains to process visual information. Fig.
24 A. At noon the sun is always at the highest point of its path. The difference in the time of noon in a given place and in Greenwich allows one to determine the longitude of a given place (in degrees) east or west of the Greenwich meridian. Since there are 360° in a circle, and the Earth makes a full revolution in 24 hours, it is easy to calculate that 1 hour of time corresponds to 360°:24=15°.
B. The height of the sun above the horizon at noon depends on the latitude of the area. At the equator, the sun is always directly overhead at noon. To determine the desired course, it is necessary to compare the height of the sun at noon in a given place with its midday altitude at “home,” that is, at the final destination of the journey.
According to Matthews, birds during migrations and when flying in the nesting area use techniques for navigation that are in many ways similar to those used by ship navigators (Fig. 24). In any part of the ocean (if the observer is in the northern hemisphere), the sun at noon is always at the highest point of its path and exactly in the south. The navigator determines the longitude of the place where the ship is located by measuring, using the ship's chronometer, the difference in the time of noon in this place and in some other place from which it is customary to count; The city of Greenwich was chosen as such a location. If this difference is 12 hours, then, consequently, the ship is on the other side of the globe, exactly opposite the Greenwich meridian. In addition, the height of the sun at noon shows the navigator how far north or south of the equator his ship is. If the sun is directly overhead, the ship is crossing the equator. Then, as the ship moves further, the angle between the midday sun and the horizon will decrease; in this case, the sun will “roll” to the north or south, depending on in which hemisphere the ship is sailing.
It is believed that migratory birds determine the geographical position of an unfamiliar area by assessing the difference in the angle between the midday sun and the horizon at home and in the place over which they fly. The further north the birds are from their “home”, the smaller this angle will be, the further south the larger it will be (we assume that the birds are in the northern hemisphere). Both ship's navigators and migratory birds often cannot see the sun at midday because of clouds, but they can calculate its midday position in the sky by making observations at other times and extrapolating the results. To do this, you need to measure a small portion of the arc that the sun makes as it moves across the sky, and then calculate the rest of the arc to find the noon position of the sun.
According to another theory, birds can remember what the full arc the sun makes in the sky looks like at home. During flights to their native lands, birds compare this arc with segments of the arc described by the sun, which are visible in the places where they fly. They fly in such a direction that the trajectory of the sun approaches the one that they are used to seeing in their homeland.
Both of these theories are based on observations and experiments that were carried out on birds during their migrations or near their nests; however, so far it has not been possible to carry out a single experiment that would clearly show the correctness of one theory and the inconsistency of another. Of course, it makes sense to consider only those proposed methods of navigation of birds that theoretically correspond to the capabilities of their senses. Both theories require birds to be able to detect the movement of the sun and extrapolate its position at different times of the day. In addition, they must be able to determine the moment of noon, they must have an extremely accurate sense of time and a good memory.
Apparently, all this does not go beyond the capabilities of the birds' sense organs. It is known that pigeons can detect the movements of the sun, which “moves” across the sky at almost the same speed as the hour hand moves around the face of a watch. In addition, birds can “calculate” the movement trajectory of various objects. A falcon, for example, must be able to determine the course of its fast-flying prey in a split second and adjust its flight in such a way as to overtake it. Compared to the movements of this victim, the movement of the sun is much simpler: it follows its path at a constant speed, which never changes.
The ability of birds to recognize the time of midday was demonstrated in house sparrows, which are active 13 hours a day under natural conditions in summer. When the length of daylight was artificially changed, their behavior was restructured in such a way that the middle of the activity period coincided with “artificial noon.” Birds reveal their ability to accurately sense time when they sing in a “duet”; at the same time, the songs of the male and female merge so precisely that they are simply impossible to distinguish. The gonolek (a species of African wood shrike) makes the second sound of its song 0.425 s after the first, and this interval never varies by more than 0.004 s. Proof of the good memory of birds can be the well-known ability of pigeons to return to their dovecote even after an eight-year absence. Thus, birds are theoretically quite capable of navigating by the sun; but exactly how they do this is very difficult to determine. At the same time, it is quite possible (and no one has yet proven otherwise) that they use some other methods of navigation. Just as ships steer their course using a gyroscopic or magnetic compass, birds may be able to maintain the correct course in inclement weather by using their balance organs, which alert them to any changes in direction of flight, or even by sensing the earth's magnetic field.
Two hundred years ago, Dr. Johnston asserted quite authoritatively that “swallows undoubtedly sleep throughout the winter. Many swallows, flying in a circle, form a dense ball, and then all rush into the water together and lie at the bottom of the river all winter.” It was also believed that cuckoos turn into sparrowhawks in winter. Nowadays, hardly anyone would believe that birds sleep under water or turn into animals of other species; at the same time, the precisely proven ability of birds to navigate while traveling over vast distances seems no less miraculous.
Notes:
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These experiments, conducted by Gustav Kramer, are described in more detail in the book by D. Griffin “Migration of Birds,” Mir Publishing House, M., 1966, pp. 117–120. — Approx. translation
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What do the experts say?
Scientists categorically do not recommend that owners conduct experiments with pets that do not survive in street conditions, die or suffer severe psychological trauma.
There are 250 million neurons in the cat’s brain, which provides the pet with good memory, which is divided into short and long-term. Kittens that have never interacted with people between the ages of 2 weeks and 2 months do not trust a person and will not return if they were forcibly taken into the house and ran away. Adult cats remember for a long time the place and room in which they lived, as well as the accompanying smells and sounds. When nerve cells are activated, the pet is able to remember what happened in the past and returns after a year or longer.
Scientists' opinion
Experts conducted experiments when they tried to take animals away from their usual place of residence, but the lost cat was still able to find his way back. This is explained by the animal's sensitivity to electromagnetic fields. Any changes and fluctuations in force fields are detected by the cat and allow it to navigate in remote areas. Scientists suggest that iron, which is present in the cat’s tissues, helps the pet to walk a long distance and find its home. When experimental scientists attached a piece of magnet to the cat's body, it became less oriented.
Psychics
In their opinion, cats are a bundle of energy that communicates with the owner through sounds and touches, as well as on a telepathic level. When a pet is lost, the owner is very worried, a special strong energy emanates from him, he wants the cat to return home. Presumably, therefore, even at a considerable distance, the cat feels the owner’s grief, his call, which is considered a guideline for her to return.
What is their secret?
How cats determine the correct path is influenced by:
- The ability to “scroll” in memory not only visual landmarks, but also the sounds accompanying the “picture”, characteristic of a particular area: the noise of a river, passing cars or boat engines.
- Well-developed olfactory apparatus. It is with the help of their nose that cats capture and remember the subtlest aromas, “tying” them to a certain area.
- Excellent peripheral vision. In addition to the fact that pussies are remarkably oriented in the dark, if necessary, their pupils can dilate and increase the viewing angle to a value inaccessible to humans. At the same time, they are able to track several landmarks and observe them while moving.
Thanks to its skills, the cat, looking for the way back, compares the environment with the “home” one, which is stored in its memory.
If the distance from home varies from three to five kilometers, getting to the purr’s native threshold will not be difficult
Scientists conducted a lot of research before suggesting that a special internal “compass” helps cats - ultrasensitivity, thanks to which they perceive the most insignificant changes in the world around them (for example, deviations of electromagnetic fields) and find the right path.
The most famous wanderers
With the help of their nose, cats are able to capture very subtle aromas that are inaccessible to humans, and tie them to the area.
At one time, the cat Semyon, born and raised in Murmansk, gained enormous popularity. The owners were so attached to the pet that, going south by car, they decided to take him with them. The vacation was a success, but on the way back the travelers' car broke down.
To get the vehicle in order, we had to make an unscheduled stop in Moscow. The car was repaired. But the cat, clearly starting to get nervous, suddenly disappeared. Searches in an unfamiliar huge city led to nothing, and the family was forced to return to Murmansk without their pet.
Years passed, and no one expected to see the pet again. But one day a cat appeared under the door to the apartment, very reminiscent of Semyon.
Well, except that he was too thin and looked tortured. However, he persistently scratched at the door, demanding to be let inside. The head of the family, who discovered this creature on the doorstep, could not leave it on the street. Imagine his surprise when the guest confidently walked to the bowl and, having eaten to his heart’s content, settled down to relax on the TV. The way Semyon once loved to do it. It became clear: he had returned home. This story caused a lot of noise.
They wrote about Semyon in newspapers, they filmed stories about him. Everyone admired the heroic cat, who had traveled thousands of kilometers. The film “Love Story” was even made about his adventure. And in Murmansk several years ago a monument to a fearless cat was erected.
For most cats, it is not a problem to find their home at a distance of 3 to 5 kilometers
A similar incident occurred in the USA. The owner also took her pet, the cat Thomas, on the trip. There was simply no one to leave him at home with. Only she went not to the sea, but to the mountains.
The cat disappeared during one of the stops, at a significant altitude relative to sea level. The search also came to nothing, and the hostess had already begun to mourn the poor fellow.
However, a few months later, an emaciated animal began scratching at her door. Entering the house, the cat checked out his favorite places, ate and went to rest with the air of a hero returning home. According to the owner’s calculations, he walked at least 500 km to meet her.
Of course, not all cats can return home. However, scientists believe that this is not due to a lack of ability to find the right direction. Rather, animals are hampered by fear. Or they simply do not feel the strength to overcome the huge distance.
Why did the old cat leave and not return?
Older pets often leave home when they sense death is approaching. More precisely, they do not feel their imminent death, because they do not have the gift of foresight, but, experiencing weakness, they move away from their habitat in order to calmly survive difficult times. Cats are secretive creatures; they do not like to show their weakness, primarily in order to prevent their enemies from taking advantage of their temporary illness. It is for this reason that they prefer to die not at home, but outside it.
