Life of animals in society. For those who don’t believe it, this can be easily verified by substituting Animal Flock

All animals have 3 types of social behavior

1) Solitary (asocial).
2) Herd (quasi-social)
3) Pack (social)

A single individual exists autonomously except for the mating season. To this type
include most mammals.

Which is understandable. For completely solitary behavior would lead to the extinction of the species in principle.

A typical example of an asocial animal is the common hedgehog.
Once a year, usually in the spring, waking up after hibernation, hedgehogs begin to mating season.
The males fight each other for the female, wheezing and snorting and hitting each other in the face.
Finally, the winner begins to circle the Messerschmitt around the cherished goal, impregnates the female
after several attempts.
Nature made sure that the hedgehog did not need to climb onto the female
screwing his pussy into the center of his stomach. On this family life ends. The hedgehog is spreading.
Further care of the offspring falls entirely on the female.
She digs a hole or occupies a mouse hole. Where he hatches several pieces of hedgehogs by feeding them with milk.

Similar behavior is observed in almost all asocial mammals.
In this case, competition between males is of a selection nature. That is, it performs the task of reducing the genetic
variety to the imaginary while increasing quality. It is clear that a sick or weak male simply cannot withstand the “fight”.
Males do not kill each other, but stronger and healthier males nevertheless fertilize more females, as a result, the species remains fairly genetically homogeneous, and at the same time, high-quality, healthy genes receive an advantage. That is, selection occurs even before birth, which is reasonable because resources are spent on the birth and feeding of offspring. It is better to immediately give birth to a healthier hedgehog. Especially considering that there are usually a lot of hedgehogs in a litter and that hedgehogs are born once a year.

Domestic cats demonstrate a similar example of antisocial behavior. However, their behavior is more complex
Because cats are relatives of lions. Social animals.
Males and females live on their own.
However, they occur at a certain period of the year when females begin to estrus. It usually depends on the seasons. Moreover, there are several such periods. Another feature of cats is the behavior of the mother, who leaves her kittens if they are defective, as well as the behavior of stray cats who strangle nests with strangers’ kittens. Which again contributes to a decrease in genetic diversity. Each male wants to strangle the offspring of another male in order to leave more offspring himself.

The second type of behavior is herd animals. That is, animals that are prone to unite in groups.
However, the herd exists largely without any particular hierarchy. Moreover. Herds usually form
animals of different species.
Typically, herds interact through simple interactions and signals between each member.
Spontaneous leadership happens, but it is usually temporary. It’s just that some random individual turns out to be in everyone’s sight and everyone imitates it without really thinking about its expediency. The herd is very easy to manipulate
The reproductive behavior of herd animals differs little from asocial ones. Usually the same.
During the mating season, competition occurs between males, and then the born animals join the herd. However, there are exceptions. For example, deer.
Deer live in small groups consisting of a male and a harem of females with cubs.

The hierarchy in dogs is also interesting. The dogs are not exactly a pack. More like a herd with a leader. Usually this is a female.
But in any case, the sexual behavior of young bitches is controlled by older bitches.
Young bitches remain uncovered by their active opposition. Because a bitch having offspring
already has higher value in the hierarchy. Since there is no competition between males, genetic diversity in dogs reaches its maximum.

Wolves live by different laws than dogs.
These are purely social pack animals. Males unite in a hierarchy in order to overwhelm larger prey. Reproduction occurs once a year, and the entire pack takes part in feeding the wolf cubs.

As for lions, they, in general, are kind of intermediate animals between the asocial behavior typical of cats and the social behavior typical of canines.

Lions unite in special groups called "pride". It's like a group, only there are several males. The main population of the pride is occupied by females, who are mostly relatives.
Sexually mature males are expelled from the pride. Some of them lead a solitary lifestyle, but in order to leave offspring they need to seize power in some pride. And often just to survive.
For one male by himself can hunt large prey quite problematically. In addition, the territory is controlled by prides, so a single male most often does not survive at all.
That is why lions, having seized power in a pride and killed the males, first of all deal with their offspring
For the offspring of other people’s males will inevitably gnaw on them when they grow up. Although usually their own offspring bite to death an elderly parent, seizing power in the pride.
This is all logical and reasonably arranged so that, again, the sickest individuals reproduce less.
And to increase the genetic homogeneity of the species.

That is, as we see, most social animals do not bypass the problem of selection.

The most socially advanced is the chimpanzee. In chimpanzees, males are not killed. They all live in one community. However, there is a clear hierarchy between males for access to females. Hierarchy is established by choosing an "alpha male". However, he becomes not the strongest. But the most "cunning" and the most "politician".
In any case, males somehow choose a leader in their environment through special gestures, signs, etc.
It is this male that has the most females. Females live separately, although in the same flock.
They have their own separate hierarchy, but mostly females do not compete for males.
It is not their job to choose which of the males is cooler. Females compete with each other for access to food.
Males have omegas. That is, those males who have practically no access to females at all.
Outcasts. Although in reality the ranks are not so strict. And even omega males sometimes get some kind of female.
Another thing is that all females prefer high-ranking ones. That is, males determine who is who by rank,
and the females simply follow this definition. naturally in a female in this situation
there may be many males. But they do not fight among themselves for males. They fight exclusively for food.

Moreover, in chimpanzees the sexual function is social in nature.
Males higher in the hierarchy often also fuck males lower in rank. No way back.
But this has nothing to do with “homosexuality” in human understanding, as is usually believed.
This is purely characteristic behavior of the chimponzee monkeys.

Finally, with people, the most possible different types. But in general they can be divided into two groups
Monogamous and polyamory, that is, those in which important function selection.
Monogamous relationships of the “every creature has a pair” type are as if alpha males mate with alpha females, and omega males with omega females. This type of behavior is very typical for birds.
For example, for pigeons. Pairs remain throughout life.
They make nests from twigs on the roofs of houses and feed the chicks together.

Apparently birds are genetically simpler, plus they already have a very cruel natural selection,
therefore they are usually monogamous. Although, again, not all.

Monogamy complex species excludes pre-selection and also does not provide a mechanism
maintaining genetic homogeneity of the population.
Yu.
It is because of this that human flocks are immediately divided into classes because the hierarchy still exists.
Only in the absence of its sexual meaning does it destroy genetic inequality.

Among polyamory we can distinguish natural polygamy and artificial polygamy. In the first case, males will receive an advantage due to some natural qualities, that is, genetically predetermined, which means such polygamy makes sense. In the second case, when there is no connection between the biological quality of males and the number of females he covers, or even feedback, then such polygamy is flawed.

An important feature of humans as a species is the extreme sexual activity of males. Chimpanzees eat much more. At the same time, the anatomical features of human males differ sharply from those of monkeys.
For a person, sexual intercourse is a much more complex procedure. While in chimpanzees it sometimes lasts several seconds.

Another peculiarity of humans is the fact that females have a rather difficult and painful time giving birth to offspring. This is due to the fact that the person’s head has developed too much. And in connection with this man
actually got bigger. Especially all sorts of "Aryans" there. Because a large skull must also have a corresponding spine, otherwise there will simply be a lot of problems with the spine.
People have large heads with frail bodies.
Moreover, since among the northern tribes there was selection mainly along the line of males, in order to ensure survival at the expense of brains, fighting against harsh conditions environment, and not to survive due to the number of offspring, then of course sexual dimorphism has developed weakly. Northern females simply do not have enough reproductive power.
Too much big people. However, nature, in principle, would solve this problem, for example, by slightly adjusting the balance of the body’s growth stage. That is, so that the fruit has a small head but then, due to faster growth, catches up in size.

Again, a very large percentage of people are associational by nature. Especially in the modern world.
Civilization created by people social type made it possible to sharply increase the number of people who tend to social behavior or quasi-social.

It is also clear why in any society it is not those who dominate who
demonstrate the social behavior of sniffling hedgehogs and cooing pigeons, or at least those individuals that demonstrate the behavior of chimpanzees or dogs, etc. It's clear why. Just by definition. The more social behavior individuals exhibit, the large territory they control if taken as a whole.
Hedgehogs do not control anything except their hole. And the pigeons except their nest.

These are temporary associations of animals that exhibit biologically useful organization of actions. Flocks facilitate the performance of any functions in the life of the species: protection from enemies, obtaining food, migration. Schooling is most widespread among birds and fish; in mammals it is characteristic of many canines. In flocks, imitative reactions and orientation towards neighbors are highly developed.
According to the methods of coordinating actions, flocks are divided into two categories: 1) equipotential, without pronounced dominance of individual members, and 2) flocks with leaders, in which animals are guided by the behavior of one or several, usually the most experienced, individuals. Associations of the first type are characteristic mainly of fish, but are also known in small birds, migratory locusts and some other forms. The second type of flock is usually found in large birds and mammals.

Rice. 115. The main types of structure of a school of pelagic fish (according to D.V. Radakov, 1972):
1– chassis; 2, 2a – defensive; 3 – all-round view; 4 – when feeding on plankton-eating fish; 5 – when feeding on pelagic predators

Schools of fish are very variable in size, shape, and density. They are often reformed, sometimes several times a day (Fig. 115). Typically, fish group in schools only during daylight hours, with visual contact with other individuals, and disperse at night. The protective role of schooling fish associations is very great. In experiments, single fish are caught by a predator several times faster than members of a school. The group has a “all-round view”, making it more difficult for a predator to approach unnoticed. In addition, the large number of moving individuals disorients the enemy. The bodies of fish, constantly changing the direction of movement, create a flicker that makes it difficult to fix the gaze on individual individuals, and makes targeted throws impossible. The flock quickly maneuvers in case of danger, flowing around the predator, which, having rushed into its middle, finds itself in the void (Fig. 116). The behavior of fish in a school is characterized by an imitation reflex - imitation of the actions of neighbors.
In birds, flocks are formed during seasonal migrations or, in sedentary and nomadic forms, during winter feeding. Flocks during migration are formed by those species that are characterized by colonial nesting or collective feeding. Solitary nesting and feeding species do not form flocks in flight.

In flocks of sedentary birds, there is constant signaling, sound and visual communication between individuals. Thanks to intra-flock and often inter-flock signaling, birds use both experience and the random discovery by individual individuals of favorable roosting and resting places, food sources, rising air currents, etc.
Wolf packs arise for group hunting in winter. In a group, animals manage to cope with large ungulates, which hunting alone is fruitless. During group hunting of wolves, pursuit is often practiced, going out to intercept the prey, driving the prey into an ambush, or capturing it in a ring, which requires coordination and coordination of the actions of all individuals (Fig. 117). Schooling is known for hyenas, hyena dogs, coyotes, etc. In packs of mammals, the role of leaders is great and the relationships between individuals are specific, which brings these group formations closer to herds.

Rice. 117. Scheme of a pack of wolves hunting a white-tailed deer (from G. A. Novikov, 1981):
1 – ambush site for 3–4 wolves; 2 – deer path; 3 – direction of movement of the deer; 4 – the same wolf-beater; 5 – place of death of a deer

25. Octopus Dumbo

Opens the hit parade amazing creatures funny octopus. It lives at great depths (from one hundred to five thousand meters) and is primarily engaged in searching for crustaceans and worm-like creatures on the seabed. Its name, reminiscent of a baby elephant with big ears, the octopus received thanks to two unusually shaped fins.

24. Darwin's Bat

Creatures from the bat family are found in the waters around the Galapagos Islands. They are terrible swimmers and have instead learned to navigate the ocean floor on their fins.

23. Chinese water deer

This animal has earned the nickname "Vampire Deer" for its prominent tusks, which are used in battles for territory.

22. Star-nosed

The small North American mole gets its name from the circle of 22 pink, fleshy tentacles at the end of its snout. They are used to identify starfish food (worms, insects and crustaceans) by touch.

21. Aye-aye

This photo shows one of the most unusual animals in the world called “aye-aye” or “little arm”. This native of Madagascar is distinguished by its unique method of foraging; he knocks on trees to find larvae, and then chews holes in the wood and inserts an elongated middle finger to pull out the prey.

20. "Living Stone"

Pyura Chilensis are living, breathing organisms found on Chilean beaches. Their appearance allows them to avoid predators. Interestingly, these creatures have both male and female organs and can reproduce without the help of a partner.

19. Pacu fish

Freshwater fish with human teeth are found in rivers in the Amazon and Orinoco basins, as well as in Papua New Guinea. A nightmare for local fishermen who are afraid to swim in the water because pacu confuse male testicles with nuts falling from trees into the water.

18. Drop fish

One of the strangest animals in the world. From the appearance of this creature, one can say that it is despondency incarnate. Lives in deep waters off the coast of Australia and Tasmania.

The blobfish lives in the depths and its flesh is a gel-like mass with a density slightly less than that of water. This allows the “dull” creature to stay afloat.

17. Eastern long-necked turtle

These turtles can be found throughout Australia. Their remarkable necks can reach a length of up to 25 cm.

16. Surinamese pipa

Leaf-like appearance Surinamese pipa is a natural defense against predators. These toads have unique method reproduction: the female lays eggs, and the male simultaneously releases sperm. The female dives down and the eggs fall onto her back, into the cells, where they remain until the time comes for the young peeps to be born.

15. Yeti Crab

The “hairy” claws of this crustacean, which lives in the depths of the southern part, contain many filamentous bacteria. They are needed to neutralize toxic minerals from water and, possibly, serve their host as food.

14. Bearded man

These beautiful birds live on Everest, the Himalayas and other mountainous areas in Europe and Asia. They were almost destroyed because people were afraid that bearded men would attack animals and children. Now there are only 10 thousand of them left on Earth.

13. Pike blenny

Found in the waters off the west coast of America, they can grow up to 30cm in length and have intimidatingly large mouths. Their pike blennies show each other as if they are kissing. Whoever has the biggest mouth is more important.

12. Decorated Tree Serpent

Many people's nightmare comes to life: a snake that climbs trees and then jumps down. Before jumping, the reptile curls up into a spiral, and then sharply turns around and rushes into the air. In flight, it stretches out and lands smoothly on a lower branch or other tree. Fortunately, flying snakes do not pay attention to people, they are more interested bats, frogs and rodents.

11. North American kakimitsli

The homeland of this cute animal from the raccoon family is arid areas North America. Cacomitsli are so easy to tame that miners and settlers once kept them as companions and gave them the nickname "miner's cat."

10. Striped Tenrec

It lives only in the tropical forests of Madagascar. The tenrec is somewhat porcupine-like, and the quills on the central part of the back can vibrate. With their help, animals locate each other.

9. Pink sea cucumber

He looks like a character from a science fiction film, but in reality he is a harmless creature. And it looks more like a jellyfish than its fellow sea cucumbers. Around its red mouth are tentacles that dig up edible mud from the bottom of the sea. From there it enters the creature's intestines.

8. Rhinopithecus

Famous TV presenter and naturalist David Attenborough once remarked that these amazing monkeys with their stub noses and blue “mask” around their eyes look like “elves.” And you can look at them and say that “ plastic surgery gone too far." Rhinopithecus lives in Asia, at altitudes up to 4000 meters and is rarely seen by humans.

7. Mantis crab

The colorful stomatopod, or mantis, spends most of its life hiding in burrows. Capable of breaking through the walls of aquariums by moving at speeds of up to 80 km per hour. During mating games Mantis crabs actively fluoresce, with the wavelength of the fluorescence corresponding to the wavelength that the pigments in their eyes can perceive.

6. Panda Ant

Among the most unusual animals on the planet is a furry creature with the coloring of a panda. In fact, this is not an ant, but a wingless wasp that lives in South America. It is very similar in appearance to an ant, but, unlike it, it has a powerful sting.

5. Leaf-tailed gecko

Master of disguise originally from Madagascar. Thanks to its leaf-shaped tail, it can fit into the interior of the local jungle.

4. Gerenuk

It's hard to believe that this long-necked cutie is not a mini-giraffe, but a real African gazelle. In order to reach high branches, the gerenuk lacks only the length of its neck. You still have to stand up on your hind legs.

3. Chinese giant salamander

It can grow up to 180 cm long and weigh up to 70 kg. If you are in China and see such a creature in a local pond, then know that the water in this reservoir is very clean and cold.

2. Angora rabbit

Looks like the result of a crossbreeding experiment Bigfoot with a kitten. Angora rabbits were extremely popular in the 17th and 18th centuries among European nobility. They were not eaten, but kept as pets.

1. Goblin shark (aka goblin shark)

Number one in our top 25 strange creatures along comes a rare shark, sometimes called a “living fossil.” It is the only surviving member of the family Scapanorhynchidae, with a pedigree of about 125 million years. Goblin sharks live all over the world at depths of more than 100 m, so they are not dangerous to swimmers.

In groups of the second type, hierarchy and dominance are usually absent. Animals stick together due to the instinct of packing. While hierarchical groups can be observed in almost all classes of vertebrates, schools without dominance generally occur and are especially common in the class of fish. To some extent they can be assumed to be in packs passerine birds. However, they were studied most closely in the class of fish. The fact is that schooling fish are of particular economic value. In addition, it is most convenient to study schooling behavior and the mechanisms of this behavior in schools of fish placed in aquariums and pools, and simply in reservoirs using modern technology(acoustic location, aerial observation, underwater observation and filming). Intensive research into the schooling behavior of fish was carried out in the laboratory by D.V. Radakov, who, based on his work, wrote an interesting monograph, “Schooling of Fish as an Ecological Phenomenon.” In this book, he gives his definition of a school of fish as “a temporary group of individuals, usually of the same species, which are (all or mostly) in the same phase life cycle, actively maintain mutual contact and show or can show at any moment organized actions that are biologically useful, as a rule, for all individuals of a given group. Appearance schools can often and greatly change depending on the condition of the fish and the conditions in which they find themselves.”

The main types of structure of a school of pelagic fish are proven in the diagram. Radakov paid much attention to the mechanisms of coordination (or organization) of the actions of fish in a school, which is of interest especially in connection with the absence of permanent leaders in a school of fish. In this regard, a school of fish, in the language of cybernetics, should be considered as an example of a self-governing system without central control. Radakov's experiments on some species of schooling fish confirmed the conclusion that in schools of most fish there are no permanent leaders. At the same time, the fish at the head of the school are constantly replaced by new ones from the bulk of the school. Decoding of film footage of moving schools in experimental tanks showed how fish moving in the head part, even when moving in a straight line, gradually lag behind and find themselves in the middle of the school, and when turning 180 degrees, the front ones begin to turn, but all individuals are included in the turn and as a result those walking in the rear end up in front (see figure). These experiments also showed that the role of “leader” at any given moment is played by a fairly large part of the flock. Thus, for juvenile herring and carp fish, it was proven that a change in the behavior and movement of the entire school was determined by a corresponding change in part of the school if this part in number was at least 30-40% of total number individuals of the flock. Signaling in this case consists of transmitting the behavioral characteristics and speed of movement of a certain part of the flock, which at that moment performs the function of the initiator of a behavioral reaction, to the rest of the members of the flock.

In addition, while experimenting in the pools of the Institute of Oceanology of the Academy of Sciences of the Republic of Cuba with schools of Atherinomorus stipes Muller a. Troshel, D. V. Radakov established using filming that in the event of local fright in fish that make up a small part of the school, throughout the school a “wave of excitement” runs through. This is a signal zone that quickly moves through the school, in which fish instantly react to the actions of neighbors with changed body posture. At the same time, the fish themselves hardly move, but bend their tail, as if preparing to throw, and the movement of the “wave of excitation” reaches a speed of 11.8-15.1 m/sec, i.e. it is 10-15 times higher than the maximum ( throw) swimming speed of Atherinomorus (Fig. 28). Thus, the startle signal is usually transmitted through a flock of Aterinomorus faster than in a second. Further, this signal can either fade out or cause a “flow of movement” of the entire flock or part of it. “Movement flow” was observed in schools of almost all fish species studied. In turn, having arisen in part of the school, it can fade out or turn into an “avalanche-like flow” of the entire school, which depends on the reactivity of the fish, the number of them in the “flow,” the speed of its movement and the distance between the “flow” and the rest of the fish in the school. To a large extent, the general reaction of the flock depends on the strength and direction of the frightening stimulus.

The protective value of the flock.

For animals in natural conditions, where they are usually surrounded by enemies, aggregation in large groups would seem to increase their ability to defend, if these groups themselves do not have defensive abilities. But since animals belonging to very different taxa live in groups (flocks, herds, colonies) (from time to time or permanently), the thought involuntarily comes to mind that such groups represent convergent defensive adaptations that serve to maintain the population size of the species.

And, indeed, research is revealing an ever-increasing “arsenal” of defensive capabilities of an organized group of animals. First of all, a group of animals that conducts “all-round tactics” notices its enemy at a much greater distance than one individual. Therefore, it is much more difficult for a predator to approach a group of animals within throwing distance. Single minnows became easier prey for pike. In schools of most vertebrates, animals can rest or feed more calmly, since some of them (accidentally or even on purpose) act as “sentinels” and, when danger appears, alert the entire group with movements or sounds. This is followed by various defensive actions of the entire group.

Animals of a number of species, united in groups, actively defend themselves from enemies and even attack them. This behavior is known for ungulates (bulls, pronghorns and musk oxen). These animals, when attacked by wolves and some other predators, often form a square, and, hiding the calves in the middle, become horns outward, organizing all-round protection. Sea gulls, like crows, having united in nesting colonies, often attack predators and drive them away. It should be remembered that active methods of group defense also exist in the branch of protostomes, where a number of species of social Hymenoptera actively defend their nests and colonies collectively, attacking enemies and using their “weapons.”

Such active protection- attack is typical for those animals leading a group lifestyle, which for one reason or another cannot flee from enemies by flight, being confined to permanent places(nests with offspring, colonies of hymenoptera, weak young animals) and at the same time have different attack capabilities.

Many school animals escape from predators by running, flying away, or swimming away from them in a close group. It would seem that an increased number of individuals in a school increases the possibility of them being caught by a predator, but scientific research data show the opposite: in some cases, fish, birds and mammals, as well as some other animals, staying in schools, turn out to be less accessible or even completely inaccessible to predators. Even fish, feeding on invertebrates (for example, daphnia) found in dense aggregations, eat them less intensively than at more sparse concentrations. This phenomenon is called the “embarrassment effect” of a predator due to the large number of prey. In pursuit of a school of fish, a daytime predator seems to be “disoriented” by a large number of flashing fish, its pursuit becomes less purposeful, throws follow one after another and the vast majority of them end in misses. At the same time, the pursuit of one fish is very directed and ends with one successful throw.” This gave rise to calling the described phenomenon “predator disorientation” due to the large number of victims.

The predator's disorientation is further increased as a result of special defensive "maneuvers" of the pack. These maneuvers were repeatedly observed and recorded by D.V. Radakov by filming for a number of marine and freshwater fish, both in relation to living predators and their models. “Maneuvering” consists in the fact that when a predator throws itself at a school that is in a state of all-round visibility, the fish of the nearest part of the school scatter away from the predator in a fan forward and to the sides, creating a constant “emptiness” in front of the predator’s muzzle, and, swimming a little, immediately turn around to the tail of the predator against the direction of its throw. In this case, often the flock, having divided into two parts, unites again and watches the retreating predator. This maneuver, when plotted on paper, resembles the letter F, with the predator's path making up the vertical part of this letter (see Fig. A). For this similarity, such a flock maneuver is called the “F-maneuver.” Such maneuvering has been recorded for a number of fish in experiments in large pools. They were noted when chasing mullet and sea burbot after schools of silverside (Atherina mochon pontica Euch.), garfish (Belone belone (L.)) for schools of anchovy (Engraulis encrasicholus (L.)), horse mackerel (Trachurus mediterraneus ponticus Aleev), for flocks of fry of mullet, pike, flocks of redfish and in a number of other cases.

for a school of gerbils (Ammodytidae) being pursued by a swimmer. At the moment of sudden fright (for example, a attack from a predator), a school of small fish often scatters like a fan, which also disorients the predator. A flock that disperses in this way usually quickly recovers. It should be noted that the pattern of response of a school of pelagic fish to a predator and the specifics of its maneuvering also largely depend on the relationship between the direction of movement of the school and the movement of the predator.

These features of schooling behavior of fish in daylight conditions significantly complicate the hunting of fish in a school by predators. Experiments conducted by D.V. Radakov and his colleagues showed approximately the same thing: fish in schools, when attacked by predators, turned out to be much less accessible to them than single individuals, and were exterminated 5-6 times slower. This has been proven in both marine and freshwater fish. As Radakov writes, “a predator, attacking a school, does not pursue any one fish until it catches it. Having first chased one and missed another, he rushes after another, after a third, until finally he manages to grab one of the victims. As a result, it takes longer to catch it than if there is a single fish in the aquarium, the pursuit of which turns out to be more purposeful.”

Usually, hungry predators, placed in sufficient light along with a school of prey fish, began an energetic chase in the first minutes and during this time sometimes managed to grab several fish. During these first minutes, as a result of the frightening influence of the predator, the flock became denser, taking on a “defensive” structure (see Fig. B). This is still to a greater extent reduced the efficiency of hunting, and accordingly its feeding activity decreased, and in some cases stopped completely. It can be assumed that the cessation of hunting is due to the fact that the energy expended by the predator on the chase turns out to be significantly greater than the energy received from food. Thus, hunting becomes energetically unprofitable.

When studying the defensive significance of schooling behavior in fish, their chemical defense signaling is of particular interest. This alarm was first discovered by Frisch, who found that when one minnow was wounded, the entire flock became frightened, scattered or went to the side. Frisch showed that an extract from the skin of a freshly killed minnow has the same effect on the school. These studies, continued by Frisch and other researchers, showed that in the skin of a number of fish species there are special flask-shaped cells that have no connection with the surface and contain substances that, when the skin is wounded, are released into the water and immediately cause a strong fear reaction in fish of this species. This substance is called the “scare substance”, and it has been found that it is perceived through the sense of smell even in very small concentrations. Frisch, in experiments with minnows, calculated that the threshold concentration of this substance in water was approximately 1.4 10 10 g/l. The “fear substance” (sometimes called the “alarm pheromone”) and corresponding reactions have been found in the vast majority of fish of the order Cyprinifornies and in some species from other orders. This action took place differently in fish of different ecological groups: fish living in thickets and other shelters formed a group and clearly oriented toward the source of the smell, and then hid or went into shelter; benthic fish, after a short stay and rushing away from the source of the smell, hid at the bottom for a long time; fish living in the water column and near the surface reacted by leaving or rushing, and then reduced activity to form a dense protective school. Thus, we can conclude that when exposed to the “fright substance”, certain ecological stereotypes of defensive behavior of fish are formed.

Very close to this signaling is the phenomenon of the “smell of fear”, established for rodents. The smell left by a wounded live house mouse scares away its relatives from the area. It was noted that since blood stains and mouse fur residues do not have such a deterrent effect on other mice, one can think that the “smell of fear” is secreted by the corresponding glands of a frightened animal. The presence of such signals that benefit the entire pack, or population, once again emphasizes the correctness of Radakov’s conclusion that the group life of animals, and in particular pack behavior, is a phenomenon characteristic of the supraorganismal level; this is a group protective adaptation that could be created as a result of group rather than individual selection.

The protective value of a flock is also known for a number of birds. Orientologist V. E. Jacobi writes that dense and quickly maneuvering flocks of starlings, as well as some wading birds, prevent predators, and in particular the peregrine falcon, from accurately and successfully attacking and capturing a particular bird. That's why birds of prey when attacking a flock, first of all, they try to fight off one individual from the flock, and then they grab it. Often, when a hawk attacks a flock of small birds, it cannot grab any of them.

For some ungulates, flocking has a certain protective value also in relation to blood-sucking insects. In summer, when there is an abundance of midges (gadflies, mosquitoes, blood-sucking flies) reindeer gather in a dense herd. Bloodsuckers usually stick around deer in the outer rows and hardly penetrate deep into the herd. Therefore, the animals in the center of the herd calmly stand or lie down, while the outer rows of deer behave restlessly and gradually move around the center of the herd. The more active the bloodsuckers are, the more outer rows of the deer herd are on the move, but their number usually does not exceed five. From time to time, the outer deer, exhausted by the midges, force their way into the center, pushing away their neighbors. Taking into account the number of deer in the herd and the number of deer in the outer (restless) rows, it is calculated that with 500 deer in the herd, 56% of the herd is protected from bloodsuckers, at 2000-77%, and at 4000-83%.

Speaking about the protective value of group behavior, it should also be noted that animals are protected from unfavorable abiotic environmental factors. In a number of works one can find evidence that animals, having gathered in a group, thereby influence the microclimate here and therefore more easily tolerate winds, snowstorms, and excessively low or high temperatures. Mutual heating and collective temperature regulation in groups of animals of various taxa have been noted large number researchers. It is known both in colonies of social insects (bees, ants), and during the overnight roosts of some birds and for a number of gregarious mammals. Penguin gatherings during frosty storms have been repeatedly described. These Antarctic birds form dense flocks of thousands, in which birds from the side gradually move to the leeward side. At the same time, their huge mass constantly “creeps”, driven by the wind. This moving group of penguins is sometimes called a "turtle". Herds of sheep, horses, antelope and reindeer behave similarly during snowstorms. In the steppes and deserts, on hot summer days, sheep also form flocks, hiding their heads in the shadow cast by the members of the herd. Finally, many fish, snakes and some mammals, falling into hibernation, also form large wintering aggregations, in which the level of metabolism is significantly reduced.

The importance of the flock in feeding.

The meaning of a flock (or grouping in general) of animals when feeding is also quite diverse. First of all, in groups, animals find accumulations of food more easily. As experiments carried out with juvenile pollock showed, that part of the fish from the school that discovered the food and rushed to it, carried with it other fish of the school who could not see the food (it was hidden from these fish by an opaque partition), and those in their own the queue carried away even more distant members of the flock (See Fig. 3. 1). Thus, gregariousness made it easier for the fish to find food, and in a matter of seconds the entire school gathered on a cluster of food organisms discovered by only a part of its members.

The importance of a flock is also great when catching prey from those predators that use the tactics of “collective hunting”. It was shown above that fish that keep in defensive schools become almost inaccessible to single predators. However, as a co-adaptation, some predators have developed a schooling method of hunting school prey. Large perches in a school surround a school of juvenile carp fish, drive them away from their shelters and eat them. A similar phenomenon has also been described for predatory fish tropical seas. D.V. Radakov gives two of his observations: during the day off West Africa, on the surface of the water, several schools of anchovies were seen, pursued from below by dunces and sharks, and from above by gray petrels. There was foam and spray above the flocks. The swarms were about 5 m in diameter. Soon the swarms were destroyed, and in their place only slowly sinking scales could be seen. The second observation was made in the Black Sea near the Karadag biological station, where D.V. Radakov managed to approach a flock of horse mackerel in an underwater mask that attacked a flock of gerbils. The gerbil kept in a very dense flock about half a meter in diameter and, pursued from below by horse mackerel, was “literally pressed to the surface of the bottom.” The number of this flock quickly decreased. Based on these observations, D.V. Radakov concludes that a school of predatory fish presses a school of its prey to the surface of the water from below, as a result of which the fish of this school can neither escape to the sides nor hide in the depths. Next, this author does general conclusion that the schooling behavior of predatory fish is an adaptation that facilitates the capture of prey, since a school of predators can:

1) it is easier to detect a flock of victims and approach it;

2) surround the prey, preventing its escape;

3) push the prey away from ordinary shelters and, in particular, “press” it from below to the surface of the water;

4) disorient the flock of victims and introduce elements of panic into its behavior. Thus, the schooling, organized behavior of predator fish turns out to be beneficial for the entire group in terms of nutrition. This is true specifically for flocks characterized by mutually dependent, coordinated behavior, while for a simple accumulation of individuals without coordinated behavior the conclusion “the more mouths, the less each has to share” is quite suitable.

The “collective” pack hunting of predators from the canine family is widely known, in which a variety of techniques are used: “cordoning”, “chasing”, “surge”, “setting up”, etc. They are described for wolves, hyena dogs, Australian dingoes and some other predators. Collective hunting has also been described for killer whales. These cetaceans always hunt in a herd, and when hunting both walruses and dolphins, their techniques were similar: “first, they surrounded the herd, and then dealt with the victims.

The importance of flocks during migration and reproduction.

Most migrating animals migrate, gathering in large flocks that unite in moving aggregations. Based on this, it can be assumed that group behavior is an important adaptation during animal migrations. In all likelihood, gregariousness and group behavior are important in this case, first of all, in protective and food relations. For animals moving through undeveloped spaces, protection from enemies and detection of places where food accumulates and places of rest should be of primary importance. It is possible that animals in flocks find it easier to navigate during migrations. Finally, it is very likely that schooling migrations of fish are directly related to hydrodynamic calculations, which showed that a school of fish swimming in a certain formation expends significantly less energy. In general, it should be noted that the significance of pack behavior of animals during migration has been completely insufficiently studied and requires further research.

The importance of group behavior in animals during reproduction has been studied even less. During this period, some vertebrates form aggregations such as nesting colonies (in birds and fish) or rookeries (in pinnipeds). Many fish, approaching the spawning ground in large concentrations of schools, reproduce while continuing to remain in these concentrations. For example, Barents Sea cod spawns off the coast of Norway, gathering in large schools. The spawning school measured using an echo sounder had a length and width of more than a kilometer, and its thickness was 10-15 m. Such a cluster consisted, according to calculations, of several million individuals

It should be noted that mass aggregations during reproduction have also been observed in some invertebrates. Thus, rises from the bottom to the surface of the sea of Nereids, which at times form huge clusters at the surface, have been repeatedly described. An interesting incident occurred in the summer of 1944 on the White Sea; a mass of Nereis virens suddenly appeared near the shores. They floated on the surface of the sea, bending like snakes. Their bodies were 30-40 cm long. In calm weather, the water was literally teeming with these animals. Fishermen were even forced to stop fishing and report that “sea snakes” had appeared in the sea. Typically, these worms live at the bottom, and when the reproductive products begin to ripen, they swim to the surface of the water to reproduce. Thousands of Nereids suddenly appear in the water and “swarm” - they swim, bending like a snake, until the reproductive products come out into the water.

It can be assumed that all of the indicated groups and aggregations of animals are also multifunctional and may be important both for the intensification and synchronization of reproduction processes, and for the protection of producers from destruction by predators. It is also possible that the gathered animals introduce their young generation in large concentrations into the conditions that are most optimal for it.

The fickleness of flocking.

It is also worth mentioning the relative inconstancy and variability of non-family groups of group behavior of animals. In many animal species, groups (flocks, herds) are formed only at certain stages of the life cycle (migration, wintering, etc.), and during reproduction they break up into pairs and family groups. This is the case with many birds and some fish. In addition, the composition of the formed flocks very often changes as a result of mixing. So we cannot say with all certainty that groups are a permanent phenomenon.