• Go to section heading: * Revealed secrets from the life of birds

The voice of the birds. Birdsong.

V.D. Ilyichev, O.L. SILAEV

The voice of a bird is almost as unique as its flight. Both are provided by structures that are peculiar only to birds: flight - by feathers with their special microstructure, and various sounds, primarily from the lower larynx, where the voice-forming organ is located. This distinguishes the voice of birds from the voice of mammals, the source of which is the upper larynx, located on the border of the oral cavity and trachea.

The vocal apparatus of mammals is characterized by supporting cartilages that provide and support the pharyngeal fissure, which, in fact, forms the sound. The pharyngeal fissure is limited by paired semilunar cartilages. The upper larynx of mammals is also characterized by the thyroid cartilage and the epiglottis.

Between the thyroid and arytenoid cartilages inside the larynx is the glottis, bounded by the vocal cords. The vocal cords are folds of the mucous membrane, inside which there is an elastic tissue. In some species, under these folds there is a pair of false vocal cords, which are much less developed.

Some mammals have Morgagian ventricles, pits located between the upper and lower vocal cords. Unpaired sacs between the thyroid and epiglottic cartilages are found in narrow-nosed monkeys, gazelle, and reindeer. The resonance of these bags amplifies the voice. The mammalian larynx is innervated by the superior and inferior laryngeal nerves, branches of the vagus nerve.

In the lower part of the trachea, close or fused cartilage rings form a drum. Between the trachea and the bronchi are enlarged bronchial semirings. Between the second and third semirings, the outer side forms a thin mucous membrane - the external vocal membrane (tympanic membrane). The elastic thickening on the inside of the third half ring is called the outer vocal lip. The inner vocal lip, attached between the free ends of the bronchial semirings, is located on the opposite side of the bronchi facing the midline of the body.

The connection of the inner walls of the bronchi provides a cartilaginous tragus with a semilunar fold. The inner surface of the bronchi below the inner lips is covered by the internal vocal membrane. At the same time, the internal vocal membranes of each of the bronchi are connected by an elastic ligament - bronchosma. This type of lower trachea, which combines elements of the trachea and bronchi, is called tracheobronchial and is typical primarily for passerines and parrots, as well as for kingfishers, cuckoos, hoopoes and some other birds.

Much less common are the tracheal and bronchial types of the lower larynx, in which, as is clear from the names, elements of the trachea and bronchi are predominant in the structure. Finally, there are orders of birds with complete or partial reduction of the vocal apparatus - they lack vocal membranes, tragus, etc.

In the work of the lower larynx, the sternohyoid muscles are of great importance, innervated by the hypoglossal and vagus nerves and providing complex and varied movements of individual elements of the lower larynx.

The sternohyoid muscles reach their greatest development in representatives of the passerine order - in songbirds, their number reaches 7–9 pairs. Parrots have 3 pairs of such muscles; in cranes, cuckoos, hoopoes, owls, nightjars, woodpeckers, penguins, loons, grebes, lamellar-billed, palmedes, chicken and pigeons and some others - 1 pair. The lower larynx of the cassowary, African ostrich and kiwi is generally devoid of muscle.

If the laryngeal muscles are poorly developed, sounds are produced by contraction of the sternotracheal muscles, which bring the vocal membranes together and press the trachea against the bronchi. In this case, the tragus presses on the protrusion of the clavicular sac, which protrudes the internal vocal membrane. When the air passes through, the vocal membranes vibrate. Band-billed, chicken, ostriches and some other birds produce sounds in this way .....

Wherever Web went, he put his inscriptions:

"Border trespassers, beware!" These inscriptions

placed in the trees so high that only

he alone could get them. Anyone who comes to

these marks on the trees, by the smell and by the wool,

left by Web, guessed that this

a huge gray bear settled in the area ...

E. Seton-Thompson.

The life of a gray bear

Even the most cursory acquaintance with the way of life of the most diverse representatives of the animal world - be it insects, fish, birds or mammals, convinces us that the population is not a random accumulation of individuals - no, it is an ordered, organized system in a certain way. What is the basis of this organization, how is order maintained? It turns out that this is the result of a clash of interests of individual animals, each of which determines its place and position in the overall system, focusing on its fellows. To do this, animals must be able to communicate to their fellows about their needs and about the possibilities of achieving them. Therefore, each species must have certain ways of transmitting information. These are various ways of signaling, which, by analogy with our own, can be roughly called "language".

As our knowledge of signaling systems in the animal kingdom becomes more and more complete, we are again and again convinced that the analogy here is purely external, that the basis for the exchange of information in animals is completely different principles than those on which communication is based. between people. Let us first consider at least purely external differences. If we leave aside writing, then the main instrument of interrelation in a person is speech, that is, sound communication. Facial expressions and gestures also play a role. In the animal kingdom, sound communication is quite widespread, although there are a huge number of species " silent"; in whose life itpractically plays no role. The "language" of animals in general is the language of not only sounds, but also specific smells, body movements and bright colorful spots.

Even if we take those species in whose life one of the most important places is occupied by sound signaling, then here, too, purely external differences from human speech are striking. The dictionary of any modern European language includes at least 100,000 words. Of course, a much smaller number of words are used in our everyday life, but even it is very large. For comparison, we can say that the sound lexicon of the American yellow-bellied marmot includes only 8 different signals (see table). Meanwhile, vocal signaling in this species occupies the main place in the general system of information exchange.

Before discussing this table, we will immediately describe very briefly other ways of communication in the yellow-bellied marmot. so that you can get a complete picture of the entire signaling system in this species. It must be remembered that in a marmot colony, which constitutes an organized community, there is a certain hierarchy. An indicator of the social rank of each animal is the features of its behavior, demonstrated when meeting with another individual. If one of the two marmots that met at the crossroads of the colony is much lower in the hierarchical ladder than the other, then he simply tries to avoid a nose-to-nose collision and retreats. If the difference in ranks is not so great, then the animals approach and sniff each other. The more “high-ranking” marmot then raises its tail, and its less “well-born” rival obediently hunches over and keeps its tail down. Another manifestation of humility is called grooming - a higher-ranking individual begins to lick the wool

Signal name	Signal characteristic	Signal value
The basis of whistling signal (OSS)	frequency response about 4 kHz	Component of the next six signals
1. Series of whistles at long intervals	A series of OSS at intervals of 3 seconds or more	Attention!
2. A series of whistles at short intervals	A series of OSS at intervals of less than 3 seconds	Anxiety!
3. Quiet whistles	OSS series (interval length may vary)	Attention! Or anxiety!
4. Accelerating whistles	A series of OSS at gradually decreasing intervals	Attention! Or a threat!
5. "Flying" whistles	A series of OSS with varying intervals. Sounds are made on the shore	Attention! Or a threat!
6. Single whistle	Single loud OSS when fleeing into a hole	Danger!
7, Squeal	High rattling sound	fear or pleasure
8. Grinding	The sound made when the front teeth rub against each other	Threat

less high-ranking. If the subordinate does not show clear signs of submissiveness, the dominant may try to cover him up. In other words, there is a ritual imitation of sexual intercourse. In this case, the gender of the animals does not play a role: a male may try to cover another male, a high-ranking female - a low-ranking male. A fight between two marmots is extremely rare. The response to disobedience is usually a menacing forward movement, "gnashing of teeth" and a short chase, accompanied by a "barking" whistle.

Here, in essence, is the entire supply of means by which groundhogs can communicate with each other. As we can see, the arsenal is rather poor, and yet it successfully coordinates the actions of individual animals and helps maintain a certain order in the colony.

If you look closely at the above plate and the description of other ways of signaling marmots - with the help of smell and demonstrative postures, then it is easy to see that the marmots do not have so much to say to each other. Each animal must take care of its "self-affirmation" in the colony in order to take the best place in it, for example, one or more holes in the very center of the settlement, where living conditions and the possibility of successful reproduction are optimal. In the spring, at the time of the beginning of reproduction, each individual must find a marriage partner, announce its presence and readiness for mating, and protect itself from the interference of other animals in these intimate aspects of life. Females must raise offspring and, if possible, protect their offspring from numerous enemies - coyotes and birds of prey. In addition, the security of the colony is the business of all its members. That is why groundhogs have so many sound warnings about danger. Being social animals, groundhogs are forced to constantly come into contact with each other. If the conflict of interests of all the inhabitants of the colony led to constant fights, this would inevitably have an effect on the state of health of all its members and the community would be threatened with gradual extinction. Therefore, the open manifestation of aggressiveness is opposed to ritualized forms of threat, which also serve as an integral part of their "language".

Human speech is a very subtle communication tool. The hundreds of words that we have can be combined into a myriad of phrases that can be given one meaning or another even by a simple rearrangement of the same words. Many words in our language have different meanings. Marmots manage, in fact, with eight "phrases", and the semantic meaning of these "phrases" is not strictly fixed. Each of them can be used in different situations, can carry a different semantic load, sometimes, from our point of view, the exact opposite. The same can be said about demonstrative postures. Thus, the behavior of a male at the time of mating with a female is identical to the demonstration of the superiority of one animal over another, regardless of their sex. All this greatly complicates the analysis of the semantic side of signaling systems in animals.

Trying to understand the semantic meaning of the signals that animals of the same species exchange when they meet, we are actually faced with an equation with many unknowns. It is now well known that behavior depends not only on the external situation, but also to a large extent on the internal state of the animal itself. This internal state, in turn, is determined by prior behavior, of which we are often unaware. Further, the observed situation cannot be fully assessed by us - many factors that are not significant from our point of view can escape attention. The relationship between two individuals follows the principle of a chain reaction with feedback. This is a multi-stage process. At the time of the meeting, animals can be in different states, they can react differently to the same environmental factors, in particular, to the presence of a third animal of the same species. All this leads to the conclusion that the information exchange system in animals works on the principle of a “broken phone”. If there is a serious defect in the handset, then no matter how bad the audibility is, we can still understand something of what the interlocutor on the other end of the line is talking about. In animal populations, the positive effect of a “broken phone” is cumulative over time.

Useless, inadequate information is discarded, and random "correct" reactions to "not quite correct" signals lead "on average" to a useful biologicalresult. In other words, the exchange of information in animals is based on probabilistic patterns. Therefore, we sometimes fail to clearly distinguish between the external manifestation of aggressiveness and sexuality, warning and anxiety, threat and fear, and even such different states as fear and satisfaction. In short, with all our desire we will not be able to compile a dictionary of the marmot language, where each sound or body movement would correspond to a completely specific translation into human language. This translation will look like this: “most likely this, most often this, but maybe this and that, and sometimes this and that.” It would seem that this conclusion should confuse us. However, having understood that in this area we are dealing with probabilistic patterns, we can study them on this basis using statistical methods (Fig. 1).

An example is the work of B. Hazlett and W. Bossert, who conducted a statistical analysis of some forms of signaling behavior in nine species of crabs. The authors came to the conclusion that most forms of aggressive behavior in this case have some communication value. Although the responses of a crab to signals from another individual vary considerably, nevertheless, each signal statistically tends to cause or suppress one or another behavior in the recipient animal. It was even possible to calculate the average amount of information transmitted by the crab in one demonstration. It turned out to be unequal in different species and averaged 0.41 bits 1 for all studied species. The information transfer rate averaged from 0.4 to 4.4 bits per second, which is close to the information transfer rate of a "dancing" bee.

What has been said about the basic needs, which is served by the signaling system in marmots (“self-affirmation” and protection of a certain living space, achieving maximum success in reproduction, etc.), is also true for all other species of the animal kingdom as territorial (Fig. 2 ) and public ones. However, for both, these needs are achieved in different ways.

Let us first see how these problems are solved in species whose representatives lead a predominantly solitary lifestyle and come into close contact with other individuals of their species only at the time of reproduction. All sorts of dispersal mechanisms play a very important role here. This is precisely the meaning of the singing of birds. The bewitching sounds made by our best singers - the nightingale, the robin, the black-headed warbler, the oriole, are nothing but a signal addressed primarily to other males of the same species. The voice of the singing male is perceived by others as evidence that this part of the forest is already occupied and, therefore, there is nothing for the newcomer to do here. At the same time, the song has another meaning - it shows the females a place where they can find a spouse ready for life together, holding in their possession a suitable place for a nest and a plot rich in food, where they can successfully raise chicks. In most lefted birds, only males have the ability to sing, they play the main active role in the protection of the territory. But in some species, such as snow bunting, robin and black-sided wheatear, females sing and defend the territory on a par with males.

Sound signaling, which contributes to the dispersal of individuals, is not the exclusive privilege of birds. The Texas bush grasshopper has five distinct sounds, of which four are made by the male and one by the female. Of these four male sounds, two contribute to the dispersal of males, that is, they have the same meaning as the song of birds. The other two calls allow the male to find the female and make contact with her. The quiet, rustling sound made by the female also contributes to her meeting with the male. In recent years, a lot of evidence has emerged that suggests that sound signaling is widespread in many fish species as an integral part of their territorial behavior.

In solitary mammalian species, the marking of territory boundaries is widespread, as a rule, with all kinds of odorous marks. For example, in American gray squirrels, both males and females live alone throughout the year in individual areas and meet only for a short time during the breeding season. Individuals of both sexes mark the boundaries of their territories, scraping off pieces of tree bark with their teeth and wetting these “bald spots” with their own urine. We also encounter this kind of marking of the territory in other mammalian species, which, strictly speaking, cannot be called solitary. Only some males protect the territory during the breeding season and thus gain clear advantages over other, non-territorial males (see above). These are, in particular, two species of African antelopes - Thompson's gazelle and gazelleGrant. Interestingly, in these very closely related species, the methods of marking the territory are completely different. Territorial males of the first species leave odorous secretions of special preorbital glands on the branches of bushes and on tall blades of grass (about one mark for every 4 m). Males of the second species take revenge on the territory with urine and feces.

In the Australian flying fox colony, most males have their own protected areas. This is a piece of a thick branch (about a meter along it and up to two meters around), on which a male and one or more of his females hang. Having chosen a similar "site" for himself, the male marks the chosen branch with secretions of special scapular glands.

Rice. 1. The mating behavior of swordsmen and the scheme of the sequence of various acts. The thickness of the lines is directly proportional to the probability with which

any action (of Henicns, 1966)

Fig 2. Demonstrative behavior supporting coma 1 - 16 - demonstrative

flight of the male denoting right. For - different types of threatening behavior

(3 - For - 4 - 6 - options for mating behavior (4 - near the building

6 - elements of threat in the mating behavior of the male - comparenication at the dancing Wheatear: ownership of the territory and attracting a female; 2 - conflict between two males on the border of their territories); nests; 5 - "dance" of the male around the female during the formation of a pair; from 3a);

7 - poses of a worried bird (original drawing by the author)

Especially a lot of marks are applied to the branch in those places where the male himself usually hangs and where the females of his "harem" hang.

Sound signaling and marking the boundaries of the territory are just passive forms of territorial behavior. If a stranger ignores these signals and invades the boundaries of someone else's site, the owner of the latter is forced to resort to more effective measures. These are the various forms of aggressive behavior. The collision of two males - the alien and the owner of the territory, as a rule, limits
Xia mutual demonstration of threatening postures (Fig. 3).

Rice. 3 Menacing postures of males in a spider, praying mantis and sandpiper

red-necked sandpiper (1 - from Carthv , 1965; 2 - from Fabre, 1911,

3 - orig. rice. auto pa)

and in this ritual duel the owner of the territory is almost invincible. Physically, he may be much weaker than his opponent, but psychologically, his “right of first place” in this area gives him invaluable advantages. Threatening demonstrations of the owner of the territory serve for the newcomer as a rather weighty indication that the place is already occupied. In this situation, further claims would be a waste of energy, so the alien usually retreats soon, and it almost never comes to a fight. If a fight breaks out, then it is, in essence, only more advanced mutual threats. Physical collisions are short-term and only in the most exceptional cases lead to bodily injury.

We would not be entirely accurate if we did not mention that there are a number of species in which fighting is an integral part of territorial conflicts. These include the already mentioned Thompson's gazelle. R. Estes, who observed several hundreds of collisions between territorial males of this species, writes that their fight is a common phenomenon. However, this author never saw any of the duelists receive any serious injury. Interestingly, in another closely related species, Grant's gazelles, territorial conflicts are usually limited to mutual threats. All of the above leads us to the conclusion that natural selection in the course of evolution has led to the safety of collisions between males. Ethologists call this process the "ritualization" of aggressive behavior. Below we will dwell in more detail on this extremely interesting phenomenon.

The outcome of territorial conflicts is perfectly illustrated by the well-known saying "Not by the right of the strong, but by the right of the first." The inviolability of this rule made it possible to form a special view of the territory as a piece of terrain where its owner dominates over all other individuals of the same species. This point of view, which establishes links between territorial behavior and the system of social hierarchy, has been brilliantly confirmed by several recent studies, including the observations of the American scientist J. Brown on the lifestyle of the California Steller's jay.

Like many sedentary bird species that do not leave their nesting sites for the winter, these jays live in permanent pairs, which remain in their territory at the end of the breeding season. After feeding the chicks, the pair ceases to actively protect the boundaries of the site and often leaves for its boundaries. However, the summer territory of each pair remains, as it were, the center of life for both the male and the female throughout the autumn and winter, and in the spring the jays again build a nest here. During the period when the boundaries of the pair's site are not protected from other jays, birds from different sites often come into contact. This is where it turns out that the social rank of each individual is constantly changing depending on where it is at the moment.

The place of this or that bird in the general system of hierarchy is easy to determine if you observe the relationship of jays on the feeders, specially hung out for this purpose. A very definite order is established here: the highest-ranking bird of all those that are near the feeder at that moment feeds first. Only when she is sated, she gives way to the next in rank, and so on. It turned out that within its territory, its owners dominate all other jays of the same sex - the male over all other males, the female over all females. When a bird temporarily leaves the boundaries of the territory, its position on the hierarchical ladder immediately falls, and the further it has flown away from the center of its territory, the stronger it is. In fact, there are two independent systems of dominance - one among males, the other - among females. In males, the relationship of social rank with their place of residence is more pronounced than in females.

When we talked about the ways of organizing the population of the Stellerose jay in different seasons of the year, we mentioned thatthe territory is protected by each pair mainly during the breeding season. To be completely accurate, it must be said that the most zealous jays guard the boundaries of their sites in early spring, at the very beginning of the breeding season - especially those males who, for one reason or another, found themselves without a female at that time. Jays are no exception in this regard - this is a general rule for all animals with a territorial mode of existence. In these critical moments of his life, the male tries with all his might to isolate himself from possible rivalry from other males and thereby guarantee the natural development of relations with his mate. For example, in jays, these relationships change significantly at the end of winter. At this time, the rank of the female begins to fall sharply. If in winter the interests of a male and a female could somehow intersect only in the field of nutrition and there was practically no place for sexual relations, then by the beginning of spring social dominance is replaced by sexual dominance. In other words, the male “becomes the father of the family” and demands all-round submission from the female.

Much more difficult is the position of the male, who by the beginning of spring does not yet have a girlfriend. He needs to find her, which in itself is not easy, and only then win her favor. It is clear that in this situation any interference from the outside is completely undesirable, therefore the male fiercely defends his possessions from any attempt at intervention. But here an unexpected contradiction arises. All of the male's behavior during this period is aggressive by its very nature, and part of this overflowing aggressiveness inevitably falls to the lot of the unexpectedly appearing female. All authors who have observed the behavior of a male and a female of a territorial species at the time of their first meeting unanimously assert that outwardly this meeting looks like a territorial conflict between two males. We observe such a picture in insects, and in fish, and in birds, and in mammals - if these animals generally have a solitary lifestyle. The relationship of partners at this first moment of pair formation is especially complex in those species in which there is no sexual dimorphism, i.e., the female does not differ externally or very slightly differs from the male.

The course of further relationships to a very large extent depends on the behavior of the female. From the point of view of the observer, the male at this time is completely impossible. He now and then attacks the seemingly so desirable girlfriend, and she always has to dodge him. We can say that she shows maximum tolerance for all the evil antics of her gentleman. It takes several days before the newly formed pair reaches equilibrium. However, if the male is too aggressive, and the female is not tolerant enough, then the pair breaks up before it has time to finally form.

So, what we often regard as the first phase of sexual behavior in a male, in essence, is nothing more than aggressive behavior. This is one of the reasons why the old division of demonstrations into aggressive and sexual is now almost completely abandoned by the etolons. We emphasize once again that at the beginning of pair formation, high aggressiveness characterizes mainly the behavior of the male. As for the female, during this period, the so-called “pacifying behavior” is more characteristic of her, which is aimed at minimizing the aggressiveness of the male as soon as possible. This whole complex process of stabilizing the relationship of two individuals goes like a chain reaction with feedback.

As an example, we give a description of the relationship between male and female South African scorpion spiders. These small arthropods lack external sexual dimorphism. The meeting of a male and a female ready to enter into a relationship is outwardly indistinguishable from the meeting of two hostile males (Fig. 4). First male and female strike each other with very long front legs (true dangerousweapons - cheliceraeand pedipalps, as well as in a skirmish between males, are never used). After some time, the female takes a “submissive posture” - she lies down on the ground, folds her pedipalps, spreads her legs to the sides and sinks into complete immobility. Sometimes the female comes into motion and shows some aggressiveness, which makes the cavalier jump away in fright. All this goes on for several hours in a row, until the male is finally convinced that the female has fallen into a state of complete passivity and that the tophorus in the form of a special gelatinous cup can already be her and fills it with sperm. The female gets up, takes the sperm into the spermatic receptacle, and the spermatophore eats. As for the male, he does not wait for the further development of the event and hastily retreats.

Rice. 4. Ritualized Threats in African Scorpion Tuks (from Alexander, 1962)

The importance of the pacifying postures taken by the female in regulating relations between the members of the couple is evidenced by the comparison of demonstrative behavior in two species of sea colonial birds - gannets, carried out by the Englishman J. Nelson. These closely related species differ in the spatial organization of their populations, which, in turn, directly depends on the characteristics of the landscapes in which these species live. The common gannet prefers rocky coasts, where individual pairs are forced to settle very closely next to each other, because convenient places for nesting are concentrated in a small area. The white booby is not so picky, and individual pairs can settle on rocks, and on gentle slopes, and on completely flat places. Therefore, nesting colonies of this species are more sparse. If in the common booby the population density often reaches 230 pairs per 100 m 2, then in the white booby there are no more than 25 pairs per 100 m 2, and usually even less. As a result, in the first species, the territories of individual pairs are small and pressed close to each other, while in the second, they are often separated by neutral areas.

The males of the common booby have to spend a lot of effort to protect their piece of land from the encroachment of their neighbors. They are extremely aggressive, and an excess of this aggressiveness extends to the female as well. When a male tries to hit his girlfriend with his beak, she has nowhere to go - there is a foreign land around, where she will not be allowed under any circumstances. Obviously, as a result of all this, the female evolved a bright, ritualized pacifying behavior. In the white booby, the female always has the opportunity to get rid of the beatings of the male, who, by the way, does not use his beak as often as the male of the common booby. The female white booby simply leaves her territory for a while and escapes her cavalier in neutral territory. Therefore, in the females of this species, J. Nelson did not find ritual pacifying postures. By the way, we note that in the common booby, in general, all demonstrative behavior is more complex, differentiated, ritualized and carries more elements of aggressiveness in all its links - both on the part of the male and on the part of the female. Obviously, such an exaggerated development of signaling is associated precisely with the conditions of dense nesting, when contacts between individual individuals are extremely numerous, which necessitates the development of an extremely differentiated "language".

These few examples already show what an important role can be played in communication between individuals by the so-called "pacifying demonstrations". As we have already seen, in territorial species they manifest themselves in the relationship between a male and a female during the formation of a pair, as if counteracting the mutual aggressiveness of individuals who are generally not prone to close contact with their own kind, and outside the breeding season simply avoid it.

The necessity of entering into close association with another individual in order to produce offspring is contrary to the whole nature of the solitary animal.

We have already mentioned more than once that the division of animals into solitary and social is largely arbitrary. Strictly speaking, we can rightfully call solitary only those animals that are alone throughout their lives and only for a short time enter into communication with an individual of the opposite sex in order to leave offspring. There are relatively few such species. A striking example of a strictly solitary species is the common squirrel. Both males and females of this species live separately throughout the year. Only at the beginning of the breeding season does the male invade the territory of the female, who at first meets him with hostility. Relations are somehow getting better, the male fertilizes the female, spends another ten days on her site, and then goes home. The female raises the young, which, having reached full independence, immediately leave the site of their mother and settle in different directions. Each young squirrel now occupies its own site and remains on it for the rest of its life. Consequently, even in the life of such a consistent “unsociable” as a squirrel, there are still two periods when individual individuals are forced to closely communicate with each other - during the formation of short-term pairs and at the moment of joint existence - a brood. But, as they say, exceptions only prove the rule. In general, the existence of a squirrel population is determined by mutual antagonism between individuals. The male and the female, having done together what nature requires of them, no longer have any sympathy for each other, rather, on the contrary, and the male returns to his former bachelor existence. When the young are already able to stand up for themselves, the female begins to look at them as a hindrance and drives them away from her site. And they themselves do not have any kindred feelings for each other.

Among birds there are many species which we call solitary, or territorial, on the grounds that during the breeding season each pair isolates itself from all the rest, guarding the boundaries of its territory. But if we get acquainted with the life of the same species in other seasons of the year, we will be convinced that the application of the term “single”, “territorial” to them is inaccurate. First, by the end of the breeding season, the territory is rarely protected. At this time, the male, female and brood of young animals represent a single cell. Here the use of the word "single" seems completely inappropriate. Later, several broods can unite together, or they break up, and their members again randomly combine into flocks with their own kind, which, randomly mixing with other similar flocks, roam until the start of the next breeding season. Only in relatively few species of birds, such as robins, wheatears and shrikes, individual individuals outside the nesting season lead a strictly solitary lifestyle and guard the boundaries of their individual areas.

As for the species whose individuals spend the cold season in flocks, their relationship between individual individuals is based on the well-known principle: "together closely, but apart boring." It is here that we can best get acquainted with the phenomenon that ecologists call "individual distance". This is some distant analogue of a protected area. As a member of the pack, each individual tries to protect itself from all sorts of accidents, for example, from an unexpected attack by one of its fellows. Therefore, the bird retains a certain vacuum of space around itself. This is a kind of tiny territory that the animal "carries with it."

The value of the individual distance varies depending on various factors. First, it is minimal during the period of joint life of the brood. The mother squirrel keeps her babies warm and feeds them with milk. The cubs keep close to each other for a long time, thereby creating a more constant temperature for their tiny bodies, which lose a lot of heat in the air. The same thing happens in the family of such typically solitary birds as wheatears or shrikes. However, as the children grow up, clear signs of mutual antagonism appear in the family, which will later lead to its disintegration and restoration) of the solitary mode of existence typical of the species. Young shrikes sit close to each other on a branch during their rest, for about a month after leaving the nest, but then they more and more often come into conflict and no longer let their brothers and sisters near them. Mother and father feed the young even when they themselves can catch insects, but there comes a moment when the female is simply afraid to approach her overgrown offspring and does not dare to pass the caught beetle to him. The father shrike sometimes becomes furious and suddenly tries to bring down on the undergrowth a blow of his strong beak. It was at this time that one or another young shrike leaves the vicinity of his native home, and the family gradually breaks up.

The second period, when animals neglect individual distances, covers the time of pair formation. As already mentioned, for strictly solitary species, this process is rather painful. It often takes a week or even more after the first meeting of future spouses before they stop being afraid of each other and allow their partner to break their individual distance and approachclose. In many species, male and female come into bodily contact only at the moments of copulation. The rest of the time they keep aloof from each other, and any attempt on the part of one of the spouses to violate the individual distance runs into an unambiguous threat. The male and female of the small plover, feeding on the edge of the shallows and accidentally found themselves side by side, look warily at each other and bypass the meeting place. Sometimes at this moment the male rushes at the female and tries to hit her with his beak. A male Siberian thrush, having arrived with food for chicks, will never sit on a nest if a female is already there. Only when she flies away for a new portion of food, the male will take her place.

Life in the family, during which the animals are constantly forced to neglect the maintenance of individual distances, usually covers no more than two or three months a year. Throughout the rest of the year, individuals of those species that we, at the risk of being imprecise, will henceforth call "solitary", maintain individual distances between themselves - regardless of whether they are members of the same flock or collide with each other briefly and accidentally.

In different situations, the distances between individuals of a certain species may not be the same, but each species has a certain minimum distance, an attempt to violate which always causes obvious opposition. This minimum value of individual distance can serve as one of the indicators of the general level of aggressiveness in a given species. In more aggressive species, individuals usually maintain greater distances between themselves than in less aggressive species. Even very closely related species can differ greatly in this respect. Such, for example, are American jays - blue-blue and ultramarine. The first of these species is typically territorial, couples are constant throughout the year, they almost never unite in flocks after the breeding season, they continue to remain in their territory. These jays are very aggressive towards each other: at the time of the meeting, two birds rarely approach each other by more than 30 cm. The second species is more prone to a social lifestyle. Nests of individual pairs are usually located close to each other. A married couple not only allows other jays in the vicinity of their nest, but does not even prevent them from providing occasional assistance in rearing chicks. This is already the first step towards a communal way of life. Parents do not avoid the company of other birds of the same species during the breeding season, and flocks of these jays are found not only in autumn and winter, but also in summer. The birds are very tolerant, and the distance between individuals in a flock often does not exceed 5 cm.

This example can serve as an illustration of one extremely important thought: the transition to a social way of life is inextricably linked with a decrease in intraspecific aggressiveness, and one of the main indicators of such a decrease is the reduction in normal individual distances between individual individuals. If in predominantly solitary species direct bodily contact is a kind of exceptional phenomenon and is possible only at certain moments of life, when it is simply impossible to do without it, then in social species it is one of the most common forms of behavior that can be observed throughout the year. If in species of solitary relationships between adults of the same sex are built on the whole on mutual antagonism, and direct bodily contact is a consequence primarily of sexual attraction, then in species of social individuals of the same sex can closely contact each other - almost as easily as individuals of different sexes - both in the breeding season and outside it. It should be noted that the propensity for bodily contact is not the same in different social species. For example, in one of the two species of macaque, individuals come into close contact incomparably more often than in the other.

Among birds, contact behavior is very characteristic of many species from the weaver family. For example, in a flock of red finches, you can constantly see several birds - from two to nine, which sit motionless on a branch close to each other. More often, such a group of resting finches consists of two or three birds. But here another finches sit on the same branch. Having landed fifteen centimeters from the resting group, the bird tries to approach it, but, having overcome two-thirds of the distance, it unexpectedly receives a rebuff from the member of this close company closest to it. It turns out that not all finches that form a permanent flock can easily and freely enter into bodily contact with each other. J. Sparks, who studied the relationship of finches in a flock of 9 birds for a long time, found that out of 36 possible contact options, only 7 are constantly realized. These “contact” connections are very constant. Moreover, a group of individuals prone to bodily contact during rest forms a kind of cell, all members of which have a certain common rhythm of life activity - they simultaneously clean their plumage, feed, and sleep.

What determines the composition of such "contact groups"? It turns out that sexual motives play a large, although not exclusively, role here. Two sama in flashy wedding attire tend to avoid making contact. The female most willingly contacts with the male actively caring for her, but at the same time she remains paired with her former cavalier, who is usually lessardent than "outsider". Thus, these relationships are nothing more than "light flirting" - they do not have a direct connection with reproduction. The German researcher S. Zuckerman very aptly called such contacts sociosexual.

Members of the contact group in finches keep all other individuals of the flock at a distance. In these cases, the "law" of individual distances is observed. The minimum individual distance between those birds of this species that are not prone to contact with each other is 6 - 10 cm. side of the closest member of the company. However, sometimes a persistent "stranger" can achieve what he wants. To do this, he needs to take a special pacifying posture, which neutralizes the aggressiveness of the members of the "contact" group. The “alien” finches fluff up their plumage and, having overcome the “forbidden zone”, join the contact group.

Fig. 5. Alloprchning in psittacles, white-eyes and weavers (from Harnson. 1965)

One of the most effective ways a finch usually resorts to to appease an aggressive neighbor is the so-called "demonstration of an invitation to clean the feather." When two birds meet, one of which is prone to attack, the second bends or lifts its head high and at the same time puffs up the plumage of the throat or occiput. The reaction of the aggressor is completely unexpected. Instead of attacking a neighbor, he dutifully begins to sort through the loose plumage of his throat or nape with his beak.(Fig. 5). J. Sparks subjected his data to statistical processing and came to the indisputable conclusion that the “invitation to allopriing” really plays the role of a pacifying c signal.

This is just one of the few examples that shows that bodily contact between individuals in societies of venous species serves as a necessary link in regulating the relationship between members of the community. In finches, it is directly related to the processes of establishing close interindividual ties (contact behavior), or to the elimination of antagonism between individuals, individual ties between which are not so defined (alloprining).

In social species of mammals, the main system for regulating relationships within the community is the hierarchy system, and here the behavior of one or another animal at the moment of contact with others serves as an indicator of the social rank of both partners. As we mentioned at the beginning of this section, an important place in the relationship of marmots living in organized colonies is occupied by the so-called grooming, or mutual fur care. When two animals that occupy different levels of the hierarchical ladder meet, the subordinate animal allows the dominant one to lick its fur. There is some analogy here with Amaldin alloprining. By allowing a high-ranking groundhog to touch itself, the low-ranking groundhog thereby shows its humility and transfers the potential aggressiveness of the dominant into another direction.

If we turn to the ape community, be it macaques, baboons or gorillas, we find a very similar picture here. The only difference is that it is not the dominant that cleans the subordinate, but vice versa (Fig. 6). According to M. Varley and D. Symes, who studied the relationships in a group of rhesus monkeys, consisting of two males and four females, grooming is not so simply associated with a hierarchy system, as is usually thought. However, a total count of the number of all intra-group contacts associated with mutual fur grooming clearly shows that the highest-ranking male leader is much more likely to use the services of other members of the group, while the animal, the last in the hierarchy, most often cares for others. the fur of their brethren. Among the experimental monkeys, it was possible to identify pairs between which grooming relationships are observed more often than would be expected based on hierarchical relationships alone. Relationships between such individuals are based on closer individual ties, on greater mutual affection. Here we again find an analogy with the "contact" groups of finches.

The rat, which has recently left the nest, moves freely throughout the colony, ignoring the laws of hierarchy. In the first three months of life, he is insured against attacks and bites from adult animals, and at this time he has the opportunity to get acquainted with the orders that prevail in the community and acquire a position that corresponds to his physical data. The main forms of bodily contact that a young rat resorts to in the first months of its life are nose-to-nose sniffing of other animals and mutual grooming. According to the American scientist J. Calhoun, this is precisely the behavior that contributes to the accumulation of early social experience in animals.

In monkeys, grooming is a typical example of sociosexual contact. Although this kind of relationship often unites animals of the same sex, nevertheless, we can more often expect these contacts between females and males, with the former playing an active role, licking and combing the males, while the latter are limited to exposing their partner to certain parts of their bodies. . This behavior is not directly related to sexual relationships, although occasionally grooming leads to copulation.

In a colony of social insects, individuals constantly come into direct bodily contact with each other. In colonies of some species of wasps, where the females are united in a hierarchy system, a sign of submission at a meeting is the regurgitation of food, which the dominant wasp immediately eats. When two ants collide "face to face", one of the insects often "licks" the head and abdomen of the other. It is assumed that this contributes to the transfer of secretions, which have their own specific smell within each colony. Apparently, it is thanks to this smell that ants are able to easily distinguish members of their anthill from "strangers". In many species of ants, an alien who accidentally finds himself on the territory of another anthill is treated very coolly - the owners simply kill him.

Rice. 6. Grooming in common baboons (from Anthony, 1968)

Birds and mammals living in communities usually do not allow themselves such extremes, but even here the newcomers run into a wall of aggressiveness or misunderstanding. So; in red finches, a bird from another flock will under no circumstances be admitted to any of the contact groups. Even a show of appeasement will not help her.

We can now sum up all that has been said about individual distance, direct bodily contact, and soothing postures in territorial and social species.

In the former, individual distance is usually observed very strictly, and animals enter into bodily contact only at certain, relatively short periods of life. The need to make physical contact requires a lot of psychological stress. Reducing mutual aggressiveness at the time of contact is achieved by demonstrating soothing postures. Obviously, alloprining and grooming, which is not uncommon in relations between males and females in territorial species, can be attributed to the same category of pacifying behavior. In social species, members of the same community come into direct bodily contact constantly, both during the breeding season and outside it. Within the community, there are smaller groupings (“contact” groups in finches and parrots, alliances in monkeys), within which constant bodily contacts help maintain strong interindividual bonds. When members of these cells come into contact with other members of the same community, contact behavior and the accompanying postures of appeasement and submission serve to eliminate possible outbreaks of mutual aggressiveness and fights, thereby normalizing the life of the entire community.

Various forms of bodily contact are not the only way to regulate relations of domination and subordination. In studying this kind of relationship in different species of monkeys, we often come across some modes of signaling that may at first glance seem completely unexpected. So, in various species of macaques and baboons, the dominant animal, trying to intimidate an individual of a lower rank, assumes a pose in front of it that is identical to the pose of the male at the moment of copulation. Another, bullied animal, demonstrating its submissiveness, imitates the female's precopulatory posture. At the same time, the true gender of the monkeys figuring out their relationship does not play any role. In some cases, this mutual display results in direct bodily contact, which to the uninformed observer looks like normal copulation.

S. Conaway and S. Coford describe such a case: a five-year-old male, who took second place after the leader in a group of rhesus monkeys, disappeared for three days. During this time, another five-year-old male, previously occupying a third; place in the hierarchy, took the place of the absent patriarch. As soon as the latter reappeared in the group, he immediately familiarized himself with the new state of affairs, which he could hardly approve of. His obvious displeasure was expressed in the fact that he approached the male who encroached on his place, and immediately covered him, as the male covers the female. The harassed male not only “swallowed” this insult, but throughout the day followed his winner with a pathetic tail between his legs.

The use of sexual behavior in conflicts related to subordination is quite widespread in the animal kingdom, both in strictly social species (monkeys, marmots), and in those that are predominantlysolitary lifestyle (domestic cat). Something similar can be seen at the moment of territorial conflict between two males in some solitary species of birds. For example, one of the typical links in the mating behavior of the small plover is the so-called "ritual nest digging." The male lays down on the ground and, sharply throwing his paws back, makes a depression in the sand. The female, watching him from a short distance, approaches the dug hole and lies down in it, while the male, standing above it, spreads his tail wide and makes a special courtship call. Observing a hostile collision of two male plovers on the border of their territories, one can often see how these birds, being at a distance of several tens of centimeters from each other or friend, simultaneously lie down on the ground and, with typical mating cries, begin to dig holes in the sand. All these facts again convince us of how ungrateful the task of dividing demonstrations into "sexual" and "aggressive" turns out to be. The point of view of R. Johnston is involuntarily recalled, who suggests that in birds a complex mating ritual could have developed a second time from more primitive and uncomplicated threatening demonstrations.

Along with the female posture of substitution, which serves as an expression of submissiveness, in a number of species of monkeys, other displays of submission are described, which the bullied animal resorts to in more acute situations, for example, when he is threatened with beatings. At such moments, a low-ranking Rhesus falls to the ground and loses all possibility of counteracting its tormentor in any way. We see something similar in gorillas: an individual, unable to fend for itself, spreads itself on the ground, lowers its head and hides its limbs under its belly. An animal that has adopted such a pose, in fact, completely surrenders itself to the mercy of the winner, who now has the opportunity to freely strike at any vulnerable part of the body of the defeated opponent. But the effect turns out to be quite the opposite: the posture of complete submission creates an insurmountable psychological obstacle to the attack, and the aggressor, as a rule, immediately stops hostile actions and retreats.

Although our knowledge of the ways in which individuals interact in the animal world is still very fragmentary, nevertheless, a lot of facts have already been accumulated from the life of many different species. And what we now know leads us to one rather fundamental conclusion. If it is possible to overcome the brewing conflict, then this possibility is usually realized, and the relationship of two individuals belonging to the same species does not lead to open antagonism. This state of affairs is especially typical of strictly social species. If the meeting of two animals still leads to the need for a direct collision, then suchthe collision is practically safe for both sides. This is the rule for relationships between rival individuals in territorial species. Accordingly, we find two main trends in the evolution of aggressive behavior. The first, more characteristic of social types, consists in a decrease in the general level of aggressiveness or in an increase in the threshold for the manifestation of aggressive reactions. The second, observed in those species in whose life territorial relations play an important role, is expressed mainly in the ritualization of aggressive behavior. The general level of aggressiveness in these species can be very high, and the threshold for the occurrence of aggressive reactions is low, but all manifestations of aggressiveness are highly ritualized and take the form of vivid and differentiated threatening behavior. Of course, this distinction between two tendencies is very arbitrary, both of them can manifest themselves in parallel or, to one degree or another, compensate for one another, being in a complex interweaving.

The enormous positive role played by the ritualization of aggressiveness in the life and preservation of the species becomes especially evident if we consider the relationships of individuals in those animals that have organs capable of inflicting a mortal blow. We have already mentioned that the males of the South African scorpion spiders, entering into conflict with each other, never use their chelicerae - hook-shaped outgrowths of the jaws, at the ends of which ducts of poisonous glands open. Instead, they strike each other with completely painless blows with their greatly elongated forelimbs. Similarly, the poisonous teeth of the horned viper, which serve to kill its prey, are never used as weapons in hostile clashes between rival males. Fertile material for studying various forms of ritualization are those groups of ungulates whose males are armed with horns of various shapes (goats, sheep, deer, antelopes, etc.). At first glance, these horns give the impression of a dangerous weapon, and, considering them, we mentally imagine a fight between two so thoroughly armed males as a merciless bloodshed. However, even a slightly closer examination of the shape of the horns in most species of ungulates makes us doubt that such a weapon can cause any serious injury to an opponent. Indeed, in many species the horns are inward-curved, or pointing backwards, or branching many times, while short, pointed horns pointing straight ahead would be most effective as a weapon of attack.

A comprehensive study of horns in ungulates allowed the Canadian researcher W. Geist to build a veryinteresting and plausible hypothesis regarding the evolution of these mysterious organs. First of all, he came to the conclusion that horns do not play a significant role in defense against predators, and therefore their evolution must be considered in terms of the relationship of individuals within a species (that is, in terms of social behavior). W. Geist identified four main stages in the evolution of horns and, accordingly, in the evolution of demonstrative behavior in ungulates
(Fig. 7).

The first stage is the short, sharp, forward-pointing horns that we see in the American bighorn goat. When meeting with each other, the males stand side by side with their heads in different directions. First, each of them demonstrates to the opponent his lateral contour, the characteristic outlines of which are due to the long fringe of hair on the chin, chest, front legs and belly. Such a demonstration of side, according to W. Geist, is the original, primitive form of ritual behavior. It occurs in species in which the "demonstrative organs" (in this case, an elongated fringe of hair) are dispersed over the entire surface of the body. Horns in this case serve as a true weapon; indeed, the male snow goats, having performed the ritual of "acquaintance", try to deliver a side blow to the enemy with a sharp short horn. This blow usually falls on the belly or thigh of the hind leg. I must say that it comes to a true fight extremely rarely and, as a rule, animals are limited to mutual threats: they butt bushes, ferociously dig the ground with their hooves. But in case of a possible fight, the mountain goat has special adaptations that minimize the danger of being struck by a sharp horn. The skin of these animals is very thick - the Eskimos have long used it to make shields. In addition, the body is covered with thick hair, which greatly softens the blow.

Three subsequent stages in the evolution of horns are associated with the concentration of "demonstrative organs" in the front of the body (the mane and beard of bison and aurochs), and then on the head (horns of antelopes, deer, rams). In the latter case, the elongated branching or curled horns become the main "demonstrative organ". Demonstrative threatening behavior also changes accordingly. The side-to-side meeting in the course of evolution is gradually replaced by a head-to-head meeting. We see the transition from the first type of demonstrations to the second with our own eyes, observing the aggressive behavior of a bison or bison. Two bulls first become side by side, and then converge "face to face". short and sharp po g a these animals, although somewhat bent inward, still serve as a rather dangerous weapon. But it is opposed by a powerful hair shield covering the chest and shoulders of a bull. We can observe the next, third stage of evolution in antelopes and deer, whose horns are already difficult to consider as true weapons. At the time of the meeting of rivals, they serve as a "demonstrative organ", primarily attracting the attention of the enemy and forcing him to approach not from the side, but from the front. In a further fight, the horns play the role of a tool that captures the opponent's horns and deflects a possible blow. Fighting among antelopes and deer is not butting, but fighting. Two male Grant's gazelles at the moment of territorial conflict intertwine their horns and tend to knock each other to the ground, which can threaten neck dislocation (Fig. 8).

Rice. 7, Evolution of horns in ungulates. Explanations in the text (from Geist, 1966)

Rice. 8. Clash of two male Thompson's gazelle. Pay attention to the position of the horns

(from Waither, 1968)

But this kind of injuryusually counteracted by the fact that, as a rule, animals of equal strength enter the fight. Even in his youth, being a member of the “bachelor herd”, each male learns by experience to determine the potential power capabilities of the opponent by appearance and avoid serious and prolonged collisions with the obviously strongest opponent. The same behavioral mechanism plays a critical role in avoiding collisions between male wild sheep. Their huge twisted horns characterize another line in the evolution of these organs. W. Gates convincingly proved that the horns of the Canadian wild sheep serve not only as a demonstrative organ that causes the meeting of hostile males head to head. The size and shape of the horns also serve as indicators of the social rank and physical strength of their owner (Fig. 9). When two animals meet, each immediately evaluates the capabilities of the opponent, and this saves the weaker ones from maiming, which is not in principle excluded. It is easy to imagine the tremendous force with which a running ram brings down on the enemy a blow from its forehead, weighted with a pair of thick twisted horns. In this case, they can be considered as weapons only insofar as they increase the mass of the skull, but in themselves they are absolutely safe.

We can easily find similar ritual organs in representatives of any other group of the animal world. Such, in particular, are catchy, bright markings and extravagant, elongated, expanded or intricately carved feathers of many birds, modified fins of fish, skin “collars” of reptiles that change color. All these "decorations" are clearly demonstrated in front of other individuals of their species, in front of a female or rival due to specific forms of demonstrative behavior. Obviously, in the course of evolution, both the decorations themselves and the ways of displaying them developed in parallel. The demonstration of these signaling structures carries vital information that indicates to other individuals the sex of the demonstrating animal, its age, strength, ownership of a given area, etc.

Rice. 9. Ritual upon meeting an approaching wild ram demonstrates its po g, serving as an indicator of social rank

(from Gsist, 1966)

As an example, we can cite the experiments of M. Salmon and J. Stout with the identification of sex in one of the species of alluring crabs. Males have large claws that the female does not have. Each male guards a small area around his hole, where he attracts females, but does not allow other males. Experiments have shown that the large claws of the male play the role of an important "demonstrative organ". Male, guard, and territory, equally hostile pea attacked both a live male and a dead one, as well as a dead female with a male claw attached to it. On the contrary, both a live and a dead male with claws removed evoked the same “benevolent” reaction in the owner of the territory as the appearance of a normal female. A model with one large and one small claw confused the owner of the site - he either did not react to it at all, or behaved aggressively.

All these examples show how closely the evolution of behavior is connected with the evolution of the structure of the body, morphological structures. External features of the structure, arising in parallel with the formation of demonstrative behavior, form a signaling system), which animals can successfullybe guided in communicating with each other. This signaling system, based on purely external characters, is especially important in populations where individuals are highly unequal. An example of such populations are, in particular, herds of ungulates. Competing because of the "harems" males have unequal strength. The physical strength of the male is largely determined by his age. Naturally, in a herd of reindeer, a ten-year-old bull has all the advantages over a three-year-old. An external indicator of the bull's potential is its horns. The imposing appearance of this decoration in itself makes younger males keep a respectful distance from the patriarch. As a result, the latter is able to keep around him the maximum number of females and make the greatest genetic contribution to the next generation. This external signaling system, which is based on the “hierarchy of horns”, minimizes the number of fights and thereby saves a lot of energy, the loss of which could dramatically negatively affect the existence of the entire herd, as well as species 8 as a whole. Such a signaling system, as it were, creates an environment of “social predictability for each member of the population.

1 Bit - unit of information.

Literature

Dembovsky Ya. Psychology of monkeys. M., Izd-vo inostr. lit., 1963.

Lsrents K. Ring of King Solomon. M., "Knowledge", 1970. Tinbergen N. Notes of an inquisitive naturalist. M., Mir, 1970.

Tinbergen N. Animal behavior. M., Mir, 1969.

Wallace A. R. Darwinism. St. Petersburg, 1911.

Fabre J. A. Instinct and manners of insects. St. Petersburg., 1911, vol. I - II.

Chauvin R. Life and manners of insects. M., Selkhozgiz, 1960.

Ecology lesson in grade 5 on the topic "Sound signals in animals and their role in animal behavior"

Goals:

Developing: development of cognitive interest and respect for nature, observation, sustained attention, creative activity, independence, the ability to compare, draw conclusions

Educational: the formation of concepts about sound signals in animals, the ability to distinguish them.

Educational: show the connection between animals with the help of sound signals, instill respect for nature, develop love for beauty, a sense of harmony and beauty.

Equipment: computer, multimedia installation, presentation, pictures of animals, textbook, workbook.

During the classes

1. Organizing moment.

Hello guys! I'm very glad to see you. Look at each other, smile. I wish you good mood for the whole lesson.

2. Checking knowledge.

Frontal conversation. (The conversation is held on the questions of the textbook at the end of paragraph 46)

Written survey (Complete task 138 in workbooks)

3. Learning new material.

The message of students about the sound signals in animals.

Teacher's story.

The relationship between man and the animal world has always been complex and included two extremes - hunting for animals and love for them. All this led to the fact that a person began to train animals and even teach them oral speech. In the course of the co-evolutionary development of man and animals, talking animals appeared, despite the large anatomy. It seems that as our knowledge of animal behavior increases, the differences between man and animals begin to shrink. However, some of the abilities that humans possess are very difficult to detect in animals. One of these abilities is language.

It seems to us that the presence of a language is a unique property of a person.
Animals have their own "language", their own system of signals, with the help of which they communicate with their relatives in their natural habitat. It seemed to be quite complex, consisting of different ways of communication - sounds, smells, body movements and postures, gestures, etc.
Animal language
Sound language is important for animals. Since ancient times, people have believed that each species of animal that exists on Earth has its own language. Using it, the birds restlessly talk or fly away when they hear a signal of danger and alarm.
Animals also have their own "language", expressing their state. The roar of a lion is heard throughout the area - this is the king of beasts loudly announces its presence.
What are the natural sounds made by animals? These are signals expressing their state, desires, feelings - rage, anxiety, love. But this is not a language in our understanding and, of course, not a speech. The well-known zooethologist K. Lorenz notes: “... animals do not have a language in the true sense of the word. The cries and sounds they make are an innate signal code.” This is also indicated by the ornithologist O. Heinrot.
A person's language is expressed through his colloquial speech and is determined by the richness of his vocabulary - for some people it is large and bright, for others it is simple. Something similar can be observed among birds and mammals: in many of them, the emitted signals-sounds are diverse, polyphonic, while in others they are rare and inexpressive. By the way, there are completely dumb birds - vultures, they never make a single sound. Signals-sounds in animals are one of the ways of communication between them. But they have different ways of passing information to each other. In addition to sounds, there is a kind of "language" of gestures and postures, as well as a mimic "language". Everyone knows that the grin of the muzzle or the expressiveness of the eyes of the animal varies greatly depending on its mood - calm, aggressive or playful. At the same time, the tail of animals is a kind of expression of their emotional state. In the animal world, the "language" of smells is widespread; a lot of amazing things can be told about it. Animals of the feline, marten, canine and other families “mark” the boundaries of the territory where they live with their secretions. By smell, animals determine the readiness of individuals for marriage, and also track down prey, avoid enemies or dangerous places - traps, traps and traps. There are other channels of communication between animals and the environment, for example, electromagnetic location in the fish of the Nile elephant, ultrasonic echolocation in bats, high-frequency sound signals-whistles in dolphins, infrasound signaling in elephants and whales, etc.
Research has corrected the popular saying: "Dumb as a fish." It turned out that fish make many different sounds, using them to communicate in a flock. If you listen to the sounds of fish with the help of special sensitive devices, you can clearly distinguish them by their “voices”. As American scientists have established, fish cough, sneeze and wheeze if the water does not meet the conditions in which they should be. The sounds produced by fish are sometimes similar to rumbling, squeaking, barking, croaking, and even grunting, and in tsinglossus fish, in general, they resemble organ basses, croaking large toads, bell ringing and the sounds of a huge harp. But, unfortunately, in the entire history of mankind there has not been a single case where a fish spoke with a human voice.
Sound signaling exists in all animal species. For example, chickens make 13 different sounds, tits - 90, rooks - 120, gray crows - up to 300, dolphins - 32, monkeys - more than 40, horses - about 100. Most zooethologists are convinced that they convey only the general emotional and mental state of animals . Some scientists think differently: in their opinion, different types of animals have their own language of communication. Thanks to him, detailed information about everything that happens to them is transmitted. I will give examples of the languages ​​of some animals. Giraffes have long been considered dumb animals. However, studies have shown that they communicate with each other using sounds that are different in frequency, duration and amplitude in the infrasonic frequency range.
monkey tongue
Many people like to watch the behavior of monkeys in the zoo (Fig. 3). And how much shouting, noise, energetic and expressive gestures are in these "warm companies"! With their help, monkeys exchange information, communicate. Even a monkey dictionary was compiled, the first such dictionary was compiled by a scientist in 1844 in Paris. It cited 11 signal words used by monkeys. For example, “keh” means “I feel better”, “okoko, okoko” is a strong fright, “gho” is a greeting. It should be said that the famous scientist R. Garner devoted almost his entire life to studying the language of monkeys and came to the conclusion that monkeys really speak their native language, which differs from human only in the degree of complexity and development, but not in essence. Garner so learned the language of the monkeys that he could even freely communicate with them.
Dolphin tongue
Dolphins are of great interest to scientists because of their good learning ability and diverse activities that are shown in contact with humans. Dolphins easily imitate various sounds and imitate human words. In the work of the famous dolphin researcher John Lily, there was such a case when during the experiment one device broke down, but the tape recorder continued to work and recorded all subsequent sounds. In the beginning, it was heard how the dolphin reproduced the voice of the experimenter, then the buzzing of the transformer and, finally, the noise of the film camera, that is, everything that happened around the animal and what it heard.
Scientists have found that dolphins have a wealth of audio signals and actively communicate with each other using a wide variety of sounds - frequent tonal whistles, sharp pulsating sounds - clicks. Dolphins have up to 32 different complex sound signals, and it is noted that each dolphin has its own characteristic whistle - “voice”. Being alone or in a group, dolphins exchange signals, whistle, make clicks, and when one dolphin gives a signal, the other is silent or whistles at that moment. When communicating with a cub, a female dolphin makes up to 800 different sounds.
Communication between dolphins occurs continuously even if they are separated, but can hear each other. For example, if you isolate dolphins and keep them in different pools, but establish radio communication between them, then they mutually react to the emitted “interlocutor” signals, even if they are separated by a distance of 8000 km. Are all sounds emitted by dolphins real spoken language or not? Some scientists believe that this has already been indisputably proven, others are more cautious about this possibility, believing that the sounds of dolphins reflect only their emotional state and express signals related to finding food, caring for offspring, protection, etc.
The "speech" of dolphins in the form of whistles, clicks, grunts, squeaks, shrill screams is not a special coded communication system that would correspond to human speech. True, one analogy leads to the opposite idea: the inhabitants of the villages of some mountainous places in the Pyrenees, Turkey, Mexico and the Canary Islands communicate with each other over long distances up to 7 km, with the help of a whistle. In dolphins, the whistling language is used for communication and it only needs to be deciphered.
Dog life and language
Dogs are known to be the most popular among pets. The old concept of "dog's life" in the sense of hopelessness, life's hardships and inconveniences is gradually acquiring a completely different color.
significant differences in the structure of the brain and vocal apparatus.

The famous trainer V.L. Durov loved animals, studied their habits well, and perfectly mastered the skill of teaching and training animals. That's how he explained dog language. If the dog barks abruptly - “am!”, Looking at the person and raising one ear at the same time, this means a question, bewilderment. When she raises her muzzle and utters a drawn-out “ayy-y-y…”, it means that she is sad, but if she repeats “mm-mm-mm” several times, then she asks for something. Well, the growl with the sound "rrr ..." is clear to everyone - this is a threat.
I also conducted my own observations on my dog ​​and made the following conclusions:
The dog is angry - it barks and growls angrily, while baring its teeth and clinging to the ground. It is better not to approach such a dog.
The dog is frightened - he tucks his tail and ears, tries to look small, maybe even cling to the ground and crawl away. Also, if the dog is nervous or afraid, he will not make eye contact with you. This is what a delinquent puppy usually does.

Exercise : by sound signals, determine the name of the animal and write it down in a notebook.

4. Consolidation of knowledge.

Frontal conversation.

1. What are the signals - sounds in animals?

2. Does sound alarm exist in all animal species or not?

3. Is it possible to determine its behavior and desire by the sound signals of a dog? Give examples.

Homework : Prepare answers to the questions at the end of the information on the handout.

Patterns of voice formation and sound communication in birds is one of the most important trends in modern ornithological bioacoustics. The study of the functional physiology of the vocal apparatus of birds is associated with great difficulties, mainly due to the variety of morphological types of the lower larynx in different systematic groups of the class (Tereza, 1930; Ames, 1971). Recently, the analysis of the acoustic structure of the sounds emitted by birds with the help of special radio-electronic equipment has been the most promising method for studying voice formation. The use of this method in relation to early ontogeny makes it possible to reveal age-related patterns of voice in birds.

The formation of acoustic signaling in birds during embryogenesis is extremely poorly covered in the literature. Researchers focused on "clicking" sounds of embryos, as most easily recorded just before hatching.

Sound communication, being a reliable communication mechanism, is widely used by brood birds, in which the development of the downy system in embryogenesis proceeds at a faster rate than the development of vision. The microphonic potential of the chick embryo cochlea in response to low-frequency sounds is recorded on the 11th day of incubation, and the electrical activity of the eye retina is recorded only on the 18th day.

The establishment of mutual communication is facilitated by the heterochronous development of the auditory analyzer of embryos. It provides maximum auditory sensitivity before hatching in the frequency ranges corresponding to the main energy maxima in the parent's sound signals and in one's own vocalization. Acoustic afferentation at certain stages of early ontogenesis has a direct impact on the development of hearing, accelerates the process of mastering the high-frequency range characteristic of the embryo's own vocalization. The range of perceived frequencies of chicks in both brood and semi-brood birds coincides with the spectral characteristics of adult bird species-specific signals effective for the corresponding forms of behavior, which is of great adaptive importance. It consists in the fact that the species-specific sound signaling between embryos and adult birds ensures the synchronization of the hatching of the brood and the maintenance of the stability of its subsequent existence.

The development of acoustic signaling in birds in prenatal ontogenesis is mediated by the formation of pulmonary respiration. The first sound signals of embryos are formed even before they enter the air chamber of the egg. According to the time of appearance, they correspond to "spontaneous" breathing, which is carried out due to the air of the amnion cavity. In the same period, the mutual acoustic connection between the embryos and the incubating bird is also established. Such a phenomenon has been noted in waders, in the example of the black-tailed godwit, in chickadees and lamellar-beaked waders.

The beginning of the functioning of sound-producing systems among representatives of various systematic groups varies considerably. The first sound signals of embryos are single squeaks separated by long time intervals - up to 30-60 min. After the embryo enters the air chamber of the egg, its sound activity sharply increases, which indicates the appearance of true pulmonary respiration. The intensity of the squeaks increases, they can be heard even without opening the shell of the egg, but they are still separated by long pauses - 20-40 minutes. Pitting - the appearance of the first cracks on the shell - is accompanied by a grouping of individual squeaks in a series of 2-3 pulses. The motor activity of embryos at this stage of development is accompanied by intense squeaks; the frequency of their radiation increases significantly with sudden movements and vibrations of the eggs.

Duration paranatal period (from pipping of the shell to hatching) correlate in birds with the total duration of the incubation period. Noteworthy is the short paranatal period in rhea and grebes. This paradox is related to the nesting ecology of the species. Reducing the duration of the paranatal period in nandu to a minimum is a kind of adaptation of embryogenesis to arid conditions. Pitting of the shell membrane by the embryo before hatching leads to intense evaporation of moisture, which, with a long paranatal period of development in savannahs and semi-deserts, can reach a critical value and lead to the death of the clutch. In the nests of grebes, on the contrary, high humidity was noted, due to the known features of their “floating” structure. A long stay of embryos at the stage of pipping of the shell in conditions of increased (excessive) humidity can also be fatal for them. In this regard, despite the early activation of the sound-producing system of embryos, the duration of the paranatal development of the great grebe is reduced to a minimum.

"Clicking" sounds occupy a special position in the development of voices in birds. They accompany pulmonary respiration and are characteristic of embryos. There is an opinion that "clicking" sounds arise as a result of the mobility of the cartilage of the trachea, bronchi or larynx. Studies have shown that "clicks" are the second type of sound signals in chronological order during the development of voice in birds in embryogenesis. The first "clicks" - irregular and low-intensity - are recorded in embryos a few hours before the shell shell pipping. Their rhythm does not exceed 10 per minute. Series, including from 10 to 50 pulses, alternate with pauses up to 5-15 minutes long.

The pecking of the shell and the subsequent stabilization of pulmonary respiration lead to the establishment of regular and more intense "clicking" activity in the embryos. Since “clicking sounds accompany respiratory acts, their rhythm increases until hatching, being an indicator of the development and stabilization of breathing. According to the spectral-temporal parameters, they are short (10-30 ms), rhythmic broadband pulses. No species-specific characteristics of "clicking" sounds were found. The rhythm of "clicks", in addition to the age characteristics of the embryos, is directly dependent on the external temperature, which is caused by the intensification of respiratory movements. In brood and semi-brood birds, “clicking” sounds serve as the basis for acoustic stimulation of embryos, which leads to acceleration of embryonic development and synchronization of hatching of chicks in the clutch.

The transition of embryos to breathing atmospheric air is accompanied by a rhythmic organization of emitted sound signals. Certain categories of them (signals of "discomfort", "comfort") have a functional significance in the process of sound communication between embryos and incubating birds. In a number of groups, the pipping of the shell membrane and the stabilization of the pulmonary respiration of the embryos drastically change the spectral structure of the emitted signals. In general, the transition to the emission of "noise" or broadband signals, which practically do not have a pronounced frequency modulation, takes place in birds with a "primitive" type of structure of the lower larynx. Primitive type of structure of the lower larynx it is characterized by one pair of muscles, and in some species of ankle (storks) and ratites (emu, rhea, African ostrich) and it undergoes a significant reduction. A developed lower larynx (for example, in songbirds) determines the complexity of the vocal muscles (8-12 pairs); it is characterized by a strong modification of the ossified tracheal rings.

The structural-dynamic organization of signals is also different. Embryos of thick-billed guillemots are capable of emitting both individual impulses and trill sounding signals. The trill structure of signals is not characteristic of the prenatal ontogeny of slender-billed guillemots. Such an early and strong difference in acoustic signaling systems in related species of guillemots is apparently due to their joint nesting in colonies. A high level in nesting colonies of guillemots is achieved not only by interspecific, but also by individual identification in families.

The maturity and complexity of the acoustic signaling system in birds at the time of hatching is determined by the type of development and species ecological features. In the prenatal ontogenesis of brood and semi-brood birds, all the main categories of signals are formed: the sounds of “discomfort”, “comfort”, “begging for food”, etc. Only alarm signals are not recorded in embryos.

Fulmar embryos (Fulmarus glaclalis) and skuas (family Stercorariidae) at pre-hatching stages are capable of emitting all sound signals characteristic of adult birds. A comparative analysis of the juvenile and definitive acoustic signaling systems in these species indicates that age-related changes are expressed mainly in the expansion of spectral boundaries and an increase in the duration of signals. The structural organization of sound signals in embryos and adult birds is almost identical. Thus, in Probes and Skuas, the type of development of the acoustic signaling system is strictly determined. All categories of sound signals are formed in prenatal ontogenesis and, according to their structural organization, are, as it were, copies of definitive signals. Further functional differentiation and structural complication of signals does not occur.

Before hatching, the embryos actively respond with signals of "discomfort" to certain external influences: cooling, abrupt egg flips, shaking, etc. The number of pulses in a series and the rhythm of their radiation are not strictly fixed and are apparently determined by the physiological state of the embryos and external factors . "Comfort" signals are easily distinguishable by ear from "uncomfortable" signals and are perceived as a quiet chirping or whistling. The intensity of their radiation by embryos is much lower than the signals of "discomfort". “Comfort” signals are usually recorded at the end of “outbursts” of motor activity in embryos, when chilled eggs are warmed, their vibrations.

One of the varieties of "comfort" sounds are "comfort" trills. Trills are emitted by embryos at stages directly pre-hatch. Trills usually follow in end of a series of "comfort" sounds and complete it. Embryos of lamellar-billed, chicken, shepherd and some other species of birds are characterized by "sleepy" trills as one of the variants of trill sounds. They differ from the usual "comfortable" trills in their narrow spectral band and shorter pulse duration. "Sleepy" trills are common when chilled eggs are warmed, the motor activity of the embryos in this case is significantly reduced.

Immediately before hatching, the embryos "cut open" the shell of the egg: this process is accompanied by specific "instrumental" sounds arising from the friction of the egg "tooth" on the shell. The intensity of these sounds is extremely low.

The exit of chicks from the shell is accompanied by the signals of "hatching". Their radiation is caused by pain, because at this moment the umbilical “stalk” breaks in the chicks. In terms of spectral and temporal parameters, the “hatching” signals are close to the “discomfort” sounds

Sound signaling at the stages of pre-hatching in brood and semi-brood birds ensures communication between embryos in the clutch, on the one hand, and between embryos and incubating birds, on the other. Sound communication during this period coordinates the behavior of embryos and leads to the establishment of primary acoustic contact with parents, on the basis of which, after hatching, a stable relationship is formed between the adult bird and the brood. The rhythm of “discomfort” signals in embryos increases when the bird leaves the nest. In this case, they stimulate the return of the incubating bird. Magnetic recording of the sounds emitted by embryos during natural incubation made it possible to reveal some features of their sound communication with the incubating bird. Thus, the emission of alarm signals by a mother hen led to the cessation of the sound activity of the embryos. The departure of the hen from the nest evoked intense signals of "discomfort" in the embryos after 5-8 minutes, and the return of the bird and its inviting sounds activated the "comfortable « alarm. Playing the sounds of "discomfort" for the mother hen with the help of a tape recorder led to the fact that he actively emitted calling signals, moved to the nest, and tapped his beak on the egg shell. Embryos “comfortable” to the signal did not cause any particular changes in her behavior.

Thus, formation of the main types of acoustic signals ends before hatching, which subsequently ensures successful acoustic orientation of the entire brood. The transition from the acoustic perception of the external environment, typical for embryos, to the perception of complex afferentation after hatching is accompanied by the further development of signaling in chicks. New categories of acoustic signals appear that were not observed in embryos: tentative alarm and alarm-defensive. Along with this, there is a further development of the signals of "discomfort" and "comfort".