Birds are the only creatures capable of imitating human speech. In addition to parrots, starlings, crows and other birds do this. The book tells about the lifestyle and behavior of "talking" birds, primarily parrots, their maintenance in captivity, and training. Special attention is given to the dictionary of the most prominent "talkers". The structure and functions of the vocal apparatus, the auditory analyzer of birds are considered. A new teaching methodology is described, based on the formation of associations between a word and an object in parrots. Bird lovers who train budgies will find a lot of useful things for themselves.

"Talking" birds are a unique mystery of nature. Despite the fact that this phenomenon has been of interest to bird lovers for a long time, it has not yet been solved. Decades ago there was a growing interest in teaching budgerigars to "talk". It turned out that they do not just copy human speech, but can connect a word and an object, a situation and a statement that it denotes. Some of them answer the questions of a person, exchange remarks with him. What types of birds “speak”, where they live, how they behave in the wild, how their hearing and vocal apparatus are arranged, how to teach a budgerigar to speak, how to choose a suitable bird, how to keep it, how to feed it, this book tells about all this.

For zoologists, bioacoustics, animal psychologists and a wide range of readers.

On the 1st cover page: red macaw (photo by J. Holton).

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The middle ear absorbs sound wave energy. The reflection coefficients of the body and air are different. In order for sound to be absorbed and most of its energy used, a delicate eardrum with a complex supporting and regulating apparatus is needed.

In mammals, the eardrum is very small compared to the bird's, in the house mouse its area is only 2.7 mm 2, while in the warbler it is several times larger - 7.8 mm 2. And in mammals it is concave, and in birds it is convex, in the form of a high tent.

But the middle ear not only absorbs sound, it processes it, regulates its further transmission. In this sense, the logic - the more complex the middle ear, the more perfect the adjustable transmission - seems to be justified. But only in part. Because the middle ear of birds is not simpler, but different.

A general view of the middle ear of birds is shown in Fig. 5. The tympanic membrane, enlarged in size, rounded and convex outwards, in the form of a tent (in mammals it is relatively smaller and concave) is striking, the cartilaginous element attached to it from one edge - the extracolumella, continuing into the auditory ossicle, resting at the other end against the oval window of the cochlea. At the same time, birds have only one middle ear muscle that regulates the tension of the tympanic membrane.

Mammals have three auditory ossicles connected in a zigzag pattern and controlled by two muscles. Due to this, the transmission of sound is accompanied by complex lever movements that allow you to adjust this transmission. Weak sounds can be amplified, strong sounds can be weakened or blocked altogether, the signal shape and some other characteristics of it can change during transmission. The auditory ossicles that provide this can move, like a piston, to perform circular motions, shifting like a lever, and turning along its axis. But in the ear of birds there is only one bone and plus a cartilaginous element that connects it to the eardrum - the extracolumella. And just one muscle. What leverage movements are there!

For a long time, the lever mobility of the auditory column of the middle ear of birds was generally denied. Scientists believed that the single auditory ossicle moved like a piston, transmitting to the inner ear what comes to the tympanic membrane with an increase determined by the ratio of the areas of the membrane and the round window. There is no regulation.

In order to prove leverage in birds, various tricks had to be resorted to. Cut the cartilaginous extracolumella, with which the bone is connected to the tympanic membrane. Extracolumella looks like a tripod, one of the legs of which rests on the center of the membrane and stretches it (this is why the membrane in birds is convex, and not concave, as in mammals), the other two are in contact with the bone edge of the membrane. The bone grows to that point of the extracolumelli where all three of its legs converge.

Using as an indicator the bioelectrical activity of the receptor section, caused by the action of a sound click (cochlear potentials), and cutting to different levels supporting processes - extracolumelli legs, one can obtain a purely piston or purely lever character of the movements of the column and study their role in sound transmission separately. Experiments have shown that the significance of the lever mobility of the auditory column in the work of the auditory system of birds is great.

An employee of the Moscow University V. D. Anisimov developed an interesting method for studying the sound transmission system of birds - the method of a luminous point.

Rice. Fig. 5. Features of the structure and functioning of the middle ear of a bird capable of imitation of speech (Anisimov, 1971) 1, 11 - location of the elements of the middle ear before muscle contraction; III, IV - displacement of elements during muscle contraction (on the right, the corresponding changes in the myogram - EMG and the microphone component - M cochlear potentials: before contraction - a, after contraction - b, c). 1 - eardrum; 2 - bundle; 3 - supracolumellar process; 4 - infracolumellar process; 5 - muscle tendon; 6 - extracolumellar process; 7 - Platner's ligament; 8 - auditory ossicle; 9 - sole of the bone; S - signal

By gluing pieces of shiny foil reflecting light onto different parts of the sound transmission system, he registered the position of the auditory ossicle and the cartilaginous extracolumella in various dynamic states.

Another important technique developed by V. D. Anisimov was the mock-up of the sound transmission system and its functions on an enlarged kinematic model made of transparent plexiglass. Asking various modes contraction of the middle ear muscle and the tension of the tympanic membrane caused by it, it was possible to trace the nature of the mobility of the sound-transmitting system, the lever movements of the auditory column and extracolumelli.

Sputtering of crystalline silver on various elements of the middle ear, their tinting and marking made it possible to film the entire process of movements, including the lever sound transmission system. The same processes were repeated on an enlarged model of the middle ear of birds, proportionally enlarged in all links.

Thus, it was proved that the middle ear of birds, arranged differently from that of mammals, works according to the same laws and solves similar problems.

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Simple mechanisms in wildlife

In the skeleton of animals and humans, all bones that have some freedom of movement are levers, for example, in humans - the bones of the limbs, lower jaw, skull (support point - the first vertebra), phalanges of the fingers. In cats, movable claws are levers; many fish have spines on the dorsal fin; in arthropods, most segments of their external skeleton; bivalve mollusks have shell valves.

Skeletal linkages are usually designed to gain speed while losing strength. This is essential for adaptability and survival.

Especially large gains in speed are obtained in insects. The wings of some insects begin to vibrate according to electrical signals that are carried by the nerves. Each of these nerve signals results in a single contraction of a muscle, which in turn moves the wing. Two groups of opposing muscles, known as the "lifter" and "lowerer", help the wings rise and fall by pulling in opposite directions. Dragonflies can reach speeds of up to 40 km per hour in flight.

The ratio of the length of the arms of the lever element of the skeleton is closely dependent on the vital functions performed by this organ. For example, long legs greyhound and deer determine their ability to run fast; the short paws of the mole are designed for the development of large forces at low speed; the long jaws of the greyhound allow you to quickly grab prey on the run, and the short jaws of the bulldog close slowly, but hold strongly ( chewing muscle attached very close to the fangs, and the force of the muscles is transmitted to the fangs almost without weakening).

In plants, lever elements are less common, which is explained by the low mobility of the plant organism. A typical lever is a tree trunk and its continuation, the main root. The root of a pine or oak that goes deep into the ground has great resistance to tipping over (the shoulder of resistance is large), so pines and oaks almost never turn upside down. On the contrary, spruce trees, which have a purely superficial root system, tip over very easily.

Interesting linkage mechanisms can be found in some flowers (for example, sage stamens), as well as in some drop-down fruits.

Consider the structure of meadow sage (Fig. 10). The elongated stamen serves as a long arm A lever. Anther is located at its end. Short shoulder B the lever, as it were, guards the entrance to the flower. When an insect (most often a bumblebee) crawls into a flower, it presses on the short arm of the lever. At the same time, the long arm hits the back of the bumblebee with an anther and leaves pollen on it. Flying to another flower, the insect pollinates it with this pollen.

In nature, flexible organs are common that can change their curvature over a wide range (spine, tail, fingers, body of snakes and many fish). Their flexibility is due either to a combination of a large number of short levers with a system of rods, or a combination of relatively inflexible elements with intermediate elements that are easily deformable (elephant trunk, caterpillar body, etc.). Bending control in the second case is achieved by a system of longitudinal or obliquely located rods.

How? Why?"

The tournament is played as extracurricular activity. It is advisable to conduct it separately for grades 7-8 and 9-11. For 1 time, you can conduct 2 rounds of the game for 3 participants or 1 round with 6 participants. In this case, it is more reasonable to conduct a warm-up and an eloquence contest for all participants at once. Preliminarily, a lottery is held for the order of performances in the eloquence contest and when performing the tasks of the game. Participants get acquainted with the topic for speaking in the eloquence contest before the start of the game. In the third round, each participant performs 3 tasks. In the order determined by the lottery, each participant chooses the number of the question to which he will answer according to the table. After that, he receives the selected task and performs it. After completing the first task in the same order, the participants perform first the second task, and then the third. For each task, an expert group of subject teachers and students who have particularly distinguished themselves in previous games give the participants a maximum of 2 points. The task that the participant did not cope with is performed by the audience (they are also assigned the same points). After receiving the correct answer (and when no one completed the task), the participants are informed of the correct answer to the task. At the end of the game, a participant who wants to improve his tournament position can go all-in with the risk of losing all the points earned in the game. Maximum amount points for completing such a task can be taken two to three times more than for one task of the game, so more difficult tasks are taken for this stage of the game. In the process of preparing for the game, the organizer carefully selects clearly formulated tasks and answers to them from different subjects and draws up a table with task numbers. Based on the results of all stages of the game, the expert group announces the winner of the tournament and the date next game. According to the results of all rounds of the game for the year, the champion (knight) of the academic year is revealed.

Insect wing movement- the result of the work of a complex mechanism and is determined, on the one hand, by the peculiarity of the articulation of the wing with the body, and on the other, by the action of special wing muscles. In general terms, the main mechanism for the movement of the wings is as follows. The wing itself is a two-arm lever with unequal arm lengths. The wing is connected to the tergite and lateral plate by thin and flexible membranes. Slightly retreating from the place of this connection, the wing rests on a small, column-shaped outgrowth of the side plate, which is the fulcrum of the wing arm.

Powerful longitudinal and dorsoventral muscles located in the thoracic segments can lower or raise the tergite. When lowering, the latter presses on the short arm of the wing and drags it down with it. As a result, the long arm, i.e., the entire bearing plane of the wing, moves upward. The rise of the tergite leads to the descent of the wing plate. Small muscles attached directly to the wing are able to rotate it along the longitudinal axis, while changing the angle of attack. During flight, the free end of the wing moves along a rather complex trajectory. When lowered, the wing plate is horizontal and moves down and forward: a lifting force arises that keeps the insect in the air. When moving up and back, the wing is located vertically, which creates a propelling effect.

The number of wing beats in 1 s varies greatly in different insects: from 5-10 (in large diurnal butterflies) to 500-600 (many mosquitoes); in very small biting mosquitoes, this figure reaches 1000 oscillations per 1 s. In various representatives of insects, the front and hind wings can be developed to varying degrees. Only in more primitive insects (dragonflies) are both pairs of wings more or less equally developed, although they differ in shape. In beetles (neg. Coleoptera - Coleoptera) the front wings change into thick and hard elytra - elytra, which almost do not participate in flight and mainly serve to protect the dorsal side of the body. The real wings are only the hindwings, which are hidden under the elytra when at rest. In representatives of the order of bugs, only the main half of the front pair of wings hardens, as a result of which this group of insects is often called the Hemiptera order. In some insects, namely the whole order of Diptera, only the anterior pair of wings is developed, while only rudiments in the form of the so-called halteres remain from the posterior.

Question about the origin of wings not yet fully resolved. Currently, one of the most substantiated is the "paranotal" hypothesis, according to which the wings arose from simple immobile lateral outgrowths of the skin - paranotums. Such outgrowths are found in many arthropods (trilobites, crustaceans), in many fossil insects, and in some modern forms (termite larvae, some praying mantises, cockroaches, etc.). The transition from crawling to flying may have been a tree-climbing lifestyle, in which insects probably jumped from branch to branch frequently, which contributed to further development lateral outgrowths of the chest, which initially served as carrier planes during parachuting or gliding flight. Further differentiation and detachment of outgrowths from the body itself led to the development of true wings, which provide active propelling flight.

Abdomen- the last part of the body of insects. The number of segments included in its composition varies in different representatives of the class. Here, as in other groups of arthropods, a clear pattern is revealed: the lower in evolutionary terms these or those representatives are, the more complete set of segments they have. Indeed, we find the maximum number of abdominal segments in the lowest cryptomaxillaries (neg. Protura), the abdomen of which consists of 11 segments and ends with a distinct telson. In all other insects, some of the segments are reduced (usually one or several of the last, and sometimes the very first), so that the total number of segments can be reduced to 10, and in higher forms (some Hymenoptera and Diptera) to 4-5.

The abdomen is usually devoid of limbs. However, due to the origin of insects from forms that had legs throughout the entire homogeneously dissected body, rudiments of limbs or limbs that have changed their original function are often preserved on the abdomen. Yes, the squad Protura, the lower representatives of wingless insects, have small limbs on the three anterior segments of the abdomen. The rudiments of the abdominal limbs are also preserved in the open-jawed ones. In tizanur, all segments of the abdomen have special appendages - styli, on which, as on runners, the abdomen slides along the substrate when the insect moves. One pair of styli at the posterior end of the body is also preserved in cockroaches. Very widespread, especially in more primitive forms (cockroaches, locusts, etc.), cerci are paired appendages of the last segment of the abdomen, which are also modified limbs. Apparently, the ovipositors, found in many insects and consisting of three pairs of elongated valves, have a similar origin.

Insect covers, like all other arthropods, consist of three main elements - the cuticle, hypodermis and basement membrane. The cuticle is secreted by the cells of the hypodermis, which often turns into syncytium in cryptomaxillary insects. The cuticle of insects is three-layered. In contrast to that of crustaceans, it has an outer layer containing lipoprotein complexes and preventing the evaporation of water from the body. Insects are land animals. It is interesting to note that in water and soil forms living in an atmosphere saturated with water vapor, the outer layer is either not expressed at all or is very poorly developed.

The mechanical strength of the cuticle is given by proteins tanned with phenols. They encrust the middle, main layer.

On the surface of the cuticle there are various outgrowths movably articulated with the surface of the body - thin hairs, scales, bristles. Each such formation is usually the product of the isolation of one large hypodermal cell. The variety of forms and functions of the hairs is extraordinary; they can be sensitive, integumentary, poisonous.

Insect coloring in most cases it depends on the presence in the hypodermis or in the cuticle of special coloring substances - pigments. The metallic sheen of many insects is one of the so-called structural colors and has a different nature. The structural features of the cuticle determine the appearance of a number of optical effects, which are based on the complex refraction and reflection of light rays. The integuments of insects have a variety of gland values; they are unicellular and multicellular. These are the smell glands (on the chest of the bugs), the protective glands (in many caterpillars), etc. The molting glands are the most common. Their secret, released during molting, dissolves the inner layer of the old cuticle without affecting the newly formed cuticular layers. Wax is secreted by special wax glands in bees, mealybugs and some other insects.

Muscular system insects is characterized by great complexity and a high degree of differentiation and specialization of its individual elements. The number of individual muscle bundles often reaches 1.5 - 2 thousand. Skeletal muscles, providing the mobility of the body and its individual parts in relation to each other, as a rule, are attached to the inner surfaces of the cuticular sclerites (tergites, sternites, limb walls). According to the histological structure, almost all insect muscles are striated.

Insect muscles (first of all, this refers to the wing muscles of higher groups of insects: hymenoptera, dipterans, etc.) are capable of an extraordinary frequency of contractions - up to 1000 times per second. This is due to the phenomenon of multiplication of the response to irritation, when a muscle responds to one nerve impulse with several contractions.

Richly branched tracheal network respiratory system supplies oxygen to each muscle bundle, which, along with a noticeable increase in the body temperature of insects during flight (due to the thermal energy released by working muscles), provides high intensity metabolic processes occurring in muscle cells.

Digestive system begins with a small oral cavity, the walls of which are formed by the upper lip and a set of oral limbs. In forms that feed on liquid food, it is essentially replaced by channels formed in the proboscis and used to suck food and conduct saliva - the secret of special salivary glands. The walls of the upper part of the oral cavity and the tubular pharynx following it are connected to the walls of the head capsule with the help of powerful muscle bundles. The combination of these bundles forms a kind of muscular pump that ensures the movement of food into the digestive system.

IN back in the oral cavity, as a rule, near the base of the lower lip (maxilla II), the ducts of one or more (up to 3) pairs of salivary glands open. The enzymes in saliva provide initial stages digestive processes. In blood-sucking insects (tsetse flies, some types of mosquitoes, etc.), saliva often contains substances that prevent blood clotting - anticoagulants. In some cases, the salivary glands dramatically change their function. In butterfly caterpillars, for example, they turn into spinnerets, which, instead of saliva, secrete a silky thread that serves to make a cocoon or for other purposes.

The alimentary canal of insects, beginning with the pharynx, consists of three sections: the anterior, middle and posterior intestines.

The foregut can be differentiated into several parts that differ in function and structure. The pharynx passes into the esophagus, which looks like a narrow and long tube. The posterior end of the esophagus often expands into a goiter, especially developed in insects that feed on liquid food. In some predatory beetles, orthopterans, cockroaches, etc., another small extension of the foregut is placed behind the goiter - the chewing stomach. The cuticle lining the entire foregut forms numerous hard outgrowths in the chewing stomach in the form of tubercles, teeth, etc., which contribute to additional grinding of food.

This is followed by the midgut, in which the digestion and absorption of food takes place; it looks like a cylindrical tube. At the beginning of the middle intestine, several blind protrusions of the intestine, or pyloric appendages, often flow into it, serving as the main for increasing the absorption surface of the intestine. The walls of the midgut often form folds, or crypts. Usually, the epithelium of the middle intestine secretes a continuous thin membrane around the contents of the intestine, the so-called peritrophic membrane.

The final digestion and assimilation of nutrients takes place in the midgut.

"I could turn the Earth with a lever, just give me a fulcrum"

Archimedes

Lever arm- one of the most common and simple types of mechanisms in the world, present both in nature and in the world created by man.A lever is a rigid body that can rotate around some axis. A lever is not necessarily a long and thin object.

The human body as a lever

In the skeleton of animals and humans, all bones that have some freedom of movement are levers, for example, in humans - the bones of the limbs, the lower jaw, the skull, the phalanges of the fingers.

Let's take a look at elbow joint. Radiation and humerus connect together with cartilage, the muscles of the biceps and triceps also join them. So we get the simplest lever mechanism.

If you hold a 3 kg dumbbell in your hand, how much effort does your muscle develop? The junction of the bone and muscle divides the bone in a ratio of 1 to 8, therefore, the muscle develops a force of 24 kg! It turns out that we are stronger than ourselves. But the lever system of our skeleton does not allow us to fully use our strength.

A good example of the better application of leverage to the musculoskeletal system is the reverse hind knee in many animals (all kinds of cats, horses, etc.).

Their bones are longer than ours, and their special structure hind legs allows them to use their muscle strength much more efficiently. Yes, of course, their muscles are much stronger than ours, but their weight is an order of magnitude greater.

The average horse weighs about 450 kg, and at the same time can easily jump to a height of about two meters. To perform such a jump, you and I need to be masters of sports in high jumps, although we weigh 8-9 times less than a horse.

Since we remembered the high jump, consider the options for using the lever, which were invented by man. The pole vault is a very good example.

With the help of a lever about three meters long (the length of the pole for high jumps is about five meters, therefore, the long arm of the lever, starting at the bend of the pole at the time of the jump, is about three meters) and the correct application of effort, the athlete takes off to a dizzying height of up to six meters.

Pick up a pen, write something or draw, and watch the pen and the movement of your fingers. You will soon discover that the handle is a lever. Find a foothold, evaluate your shoulders and make sure that in this case you lose in strength, but gain in speed and distance. Actually, when writing, the friction force of the stylus on the paper is small, so that the muscles of the fingers do not strain too much. But there are such types of work when the fingers must work to the fullest, overcoming significant forces, and at the same time make movements of exceptional accuracy: the fingers of a surgeon, a musician.

Lever in everyday life

Levers are also common in everyday life. It would be much more difficult for you to open a tightly screwed faucet if it did not have a 4-6 cm handle, which is a small but very effective lever.

The same applies to a wrench, which you use to unscrew or tighten a bolt or nut. The longer the wrench, the easier it will be for you to unscrew this nut, or vice versa, the tighter you can tighten it.

When working with especially large and heavy bolts and nuts, for example, when repairing various mechanisms, cars, machine tools, wrenches with a handle up to a meter are used.

Another striking example of leverage in Everyday life most common door. Try to open the door by pushing it near the hinges. The door will give in very hard. But the farther from the door hinges the point of application of force is located, the easier it will be for you to open the door.

In plants, lever elements are less common, which is explained by the low mobility of the plant organism. A typical lever is a tree trunk and roots. A pine or oak root that goes deep into the ground offers tremendous resistance, so pines and oaks almost never turn upside down. On the contrary, spruces, which often have a superficial root system, tip over very easily.

The "piercing tools" of many animals and plants - claws, horns, teeth and thorns - are shaped like a wedge (a modified inclined plane); the pointed shape of the head of fast-moving fish is similar to a wedge. Many of these wedges have very smooth hard surfaces, which is what makes them so sharp.

Levers in technology

Naturally, levers are also ubiquitous in technology.

A simple "lever" mechanism has two varieties: block and gate.

With the help of a lever, a small force can balance a large force. Consider, for example, lifting a bucket from a well. The lever is a well gate - a log with a curved handle attached to it, or a wheel.

The axis of rotation of the gate passes through the log. The lesser force is the strength of the human hand, and greater strength- the force with which the bucket and the hanging part of the chain are pulled down

Even before our Era, people began to use levers in the construction business. For example, in the picture you see the use of a lever when constructing a building. We already know that levers, blocks and presses allow you to get a gain in strength. However, is such a gain given "for nothing"?

When using a lever, its longer end travels a greater distance. Thus, having received a gain in strength, we get a loss in distance. This means that by lifting a load with a small force heavy weight, we are forced to make a large displacement.

The most obvious example is the gear lever in a car. The short lever arm is the part that you see in the cabin.

The long arm of the lever is hidden under the bottom of the car, and is about twice as long as the short one. When you shift the lever from one position to another, a long arm in the gearbox switches the corresponding mechanisms.

For example, in sports cars, for faster gear changes, the lever is usually set short, and its range is also made short.

However, in this case, the driver needs to make more effort to change gear. On the contrary, in heavy vehicles, where the mechanisms themselves are heavier, the lever is made longer, and its range of travel is also longer than in a passenger car.

A simple "inclined plane" mechanism and its two varieties - wedge and screw

An inclined plane is used to move heavy objects for more high level without directly lifting them. If you need to lift the load to a height, it is always easier to use a gentle slope than a steep one. Moreover, the lower the slope, the easier it is to do this work.

A body on an inclined plane is held by a force that is ... in magnitude so many times less than the weight of this body, how many times the length of the inclined plane is greater than its height.

A wedge driven into a log acts on it from top to bottom. At the same time, he pushes the resulting halves to the left and right. That is, the wedge changes the direction of the force.

Thus, we can be convinced that the lever mechanism is very widespread both in nature and in our daily life, and in various mechanisms.

In addition, the force with which he pushes the halves of the log is much greater than the force with which the hammer acts on the wedge. Consequently, the wedge also changes the numerical value of the applied force.

Woodworking and gardening Tools represented a wedge - this is a plow, adze, scrapers, a shovel, a hoe. The land was cultivated with a plow, a harrow. Harvested with rakes, scythes, sickles.

A screw is a type of inclined plane. With it, you can get a significant gain in strength.

By turning the nut on the bolt, we raise it along an inclined plane and win in strength.

By turning the corkscrew handle clockwise, we cause the corkscrew screw to move down. There is a transformation of movement: the rotational movement of the corkscrew leads to its forward movement.