Competition in biology is important. Competition: examples, types, relationships

If in an ecological system two or more species (populations) with similar ecological requirements live together, a negative type of relationship arises between them, which is called competition.

Competition (––) is any interaction between populations of two (or more) species that adversely affects their growth and survival.

In a general sense, the word “competition” means confrontation, rivalry, competition. Competition is extremely widespread in nature.
Competitive interactions may concern space, food, light, dependence on predators and other enemies, exposure to disease, and various environmental factors.

It must be borne in mind that simply the use by organisms of the same natural resource cannot be considered competition. Negative interaction can only be discussed when this resource is in short supply and when its joint consumption has an adverse effect on the population.

Types of competition

Competition is divided into intraspecific and interspecific. Both intraspecific and interspecific competition can be of great importance in shaping the diversity of species and the number of organisms.

Intraspecific competition- this is the struggle for the same resources that occurs between individuals of the same species.

Example:

Self-thinning in plants. This process begins with the seizure of territory: somewhere in the open, not far from a large spruce tree that produces many seeds, several dozen seedlings appear - small fir trees. The first task has been completed: the population has grown and captured the territory it needs to survive. Thus, territoriality in plants is expressed differently than in animals: a site is occupied not by an individual, but by a species (more precisely, part of a population). Young trees grow and over time, an inevitable difference in growth appears between the trees: some, weaker, lag behind, others overtake. Since spruce is a very light-loving species (its crown absorbs almost all the light falling on it), weaker fir trees begin to increasingly experience shading from the taller ones and gradually dry out and die. In the end, after many years in a clearing, from a hundred fir trees, only two or three trees (or even one) remain - the strongest individuals of the entire generation.

Some organisms, under the influence of intraspecific competition for space, have developed an interesting type of behavior. He is called territoriality. Territoriality is characteristic of many species of birds, some fish, and other animals.

Example:

In birds, the territorial type of behavior manifests itself as follows. At the beginning of the breeding season, the male selects a habitat (territory) and defends it from invasion by males of the same species (birdsong in the spring is a signal of ownership of the occupied area). A male who strictly guards his territory has a greater chance of successfully mating and building a nest, while a male who is unable to secure a territory will not reproduce. Sometimes the female also takes part in protecting the territory. In a protected area, the complex task of caring for the nest and young will not be disrupted by the presence of other parental pairs.

Thus, territorial behavior can be considered an ecological regulator, since it equally avoids both overpopulation and underpopulation.

Interspecific competition- mutually negative relationships between closely related or similar ecological species living together.

Competition between species is extremely widespread in nature. The forms of manifestation of interspecific competition can be very different: from brutal struggle to almost peaceful coexistence.

Gause's principle - of two species living together with the same ecological needs, one necessarily displaces the other.

This pattern was established experimentally and described by the Russian biologist G.F. Gause. He conducted the following experiments. Cultures of two species of slipper ciliates were placed separately and together in vessels with hay infusion.

Each species, placed separately, reproduced successfully, reaching optimal numbers.

When both cultures were placed in one vessel, the number of one of the species (Paramecium caudatum) gradually decreased, and it disappeared from the infusion, and the number of the other species (Paramecium aurelia) became the same as it was when these ciliates lived separately.

Biological interspecific competition is a natural process of struggle between different individuals for space and resources (food, water, light). It occurs when species have similar needs. Another reason for the start of competition is limited resources. If natural conditions provide an excess of food, competition will not arise even between individuals with very similar needs. Interspecific competition can lead to the extinction of a species or its displacement from its former habitat.

Struggle for existence

In the 19th century, interspecific competition was studied by researchers involved in the formation of the theory of evolution. Charles Darwin noted that the canonical example of such a struggle is the coexistence of herbivorous mammals and locusts, feeding on the same plant species. Deer eating tree leaves deprive bison of food. Typical rivals are a mink and an otter, driving each other out of contested bodies of water.

The animal kingdom is not the only environment where interspecific struggle is observed; such struggles are also found among plants. It’s not even the above-ground parts that are in conflict, but the root systems. Some species oppress others in different ways. Soil moisture and minerals are taken away. A striking example of such actions is the activity of weeds. Some root systems, with the help of their secretions, change the chemical composition of the soil, thereby inhibiting the development of neighbors. Interspecific competition between creeping wheatgrass and pine seedlings manifests itself in a similar way.

Ecological niches

Competitive interaction can be very different: from peaceful coexistence to physical struggle. In mixed plantings, fast-growing trees suppress slow-growing ones. Fungi inhibit bacterial growth by synthesizing antibiotics. Interspecific competition can lead to the demarcation of ecological poverty and an increase in the number of differences between species. Thus, environmental conditions and the totality of connections with neighbors change. is not equivalent to habitat (the space where an individual lives). In this case we are talking about the entire lifestyle. A habitat can be called an “address,” and an ecological niche can be called a “profession.”

In general, interspecific competition is an example of any interaction between species that negatively affects their survival and growth. As a result, rivals either adapt to each other, or one opponent displaces the other. This pattern is typical for any struggle, be it the use of the same resources, predation or chemical interaction.

The pace of the struggle increases when we are talking about species that are similar or belong to the same genus. A similar example of interspecific competition is the story of gray and black rats. Previously, these different species of the same genus lived next to each other in cities. However, due to their better adaptability, gray rats supplanted black rats, leaving them with forests as their habitat.

How can this be explained? They swim better, they are larger and more aggressive. These characteristics influenced the outcome to which the described interspecific competition led. Examples of such collisions are numerous. The struggle between wood thrushes and song thrushes in Scotland was very similar. And in Australia, bees brought from the Old World replaced the smaller native bees.

Exploitation and interference

To understand in what cases interspecific competition occurs, it is enough to know that in nature there are no two species that occupy the same ecological niche. If organisms are closely related and lead a similar lifestyle, they will not be able to live in the same place. When they do occupy a common territory, these species feed on different foods or are active at different times of day. One way or another, these individuals necessarily have a different trait, which gives them the opportunity to occupy different niches.

Apparently peaceful coexistence can also be an example of interspecific competition. The relationships of certain plant species provide a similar example. Light-loving species of birch and pine protect spruce seedlings that die in open areas from freezing. This balance is sooner or later upset. Young spruce trees close in and kill new shoots of species that need sun.

The proximity of different species of rock nuthatches is another striking example of the morphological and ecological separation of species, which leads to interspecific competition of biology. Where these birds live near each other, their method of obtaining food and the length of their beaks differ. This distinction is not observed in different habitat areas. A separate issue of evolutionary teaching is the similarities and differences of intraspecific and interspecific competition. Both cases of struggle can be divided into two types - exploitation and interference. What are they?

During exploitation, the interaction of individuals is indirect. They react to a decrease in the amount of resources caused by the activity of neighboring competitors. consume food to such an extent that its availability is reduced to a level where the rate of reproduction and growth of the rival species becomes extremely low. Other types of interspecific competition are interference. They are demonstrated by sea acorns. These organisms prevent neighbors from attaching to the stones.

Amensalism

Other similarities between intraspecific and interspecific competition are that both can be asymmetrical. In other words, the consequences of the struggle for existence for the two species will not be the same. Such cases are especially common in insects. In their class, asymmetric competition occurs twice as often as symmetric competition. Such an interaction in which one individual adversely affects another, but the other does not have any effect on the opponent is also called amensalism.

An example of such a struggle is known from observations of bryozoans. They compete with each other through fouling. These colonial species live on corals off the coast of Jamaica. The most competitive individuals “defeat” their opponents in the overwhelming majority of cases. These statistics clearly demonstrate how asymmetric types of interspecific competition differ from symmetrical ones (in which the opponents' chances are approximately equal).

Chain reaction

Among other things, interspecific competition can cause the limitation of one resource to lead to the limitation of another resource. If a colony of bryozoans comes into contact with a rival colony, then there is a possibility of disruption of the flow and food supply. This, in turn, leads to the cessation of expansion and occupation of new areas.

A similar situation arises in the case of a “war of the roots.” When an aggressive plant shades a rival, the oppressed organism feels a lack of incoming solar energy. This starvation causes slower root growth, as well as a deterioration in the use of minerals and other resources in the soil and water. Plant competition can influence both from roots to shoots, and vice versa from shoots to roots.

Algae Example

If a species has no competitors, then its niche is considered not ecological, but fundamental. It is determined by the totality of resources and conditions under which an organism can maintain its population. When competitors appear, the view from the fundamental niche falls into the realized niche. Its properties are determined by biological competitors. This pattern proves that any interspecific competition causes a decrease in viability and fertility. In the worst case, neighbors push the organism into that part of the ecological niche where it cannot not only live, but also have offspring. In such a case, the species faces the threat of complete extinction.

Under experimental conditions, the fundamental niches of diatoms are provided by the cultivation regime. It is through their example that it is convenient for scientists to study the phenomenon of biological struggle for survival. If two competing species, Asterionella and Synedra, are placed in the same test tube, the latter will gain a niche suitable for life, while Asterionella will die.

The coexistence of Aurelia and Bursaria gives other results. Being neighbors, these species will have their own realized niches. In other words, they will share resources without fatal harm to each other. Aurelia will concentrate at the top and consume the suspended bacteria. The Bursaria will settle to the bottom and feed on the yeast cells.

Resource Sharing

The example of Bursaria and Aurelia shows that peaceful existence is possible with niche differentiation and resource sharing. Another example of this pattern is the struggle between Galium algae species. Their fundamental niches include alkaline and acidic soils. With the emergence of a fight between Galium hercynicum and Galium pumitum, the first species will be limited to acidic soils, and the second to alkaline soils. This phenomenon in science is called mutual competitive exclusion. At the same time, algae need both alkaline and acidic environments. Therefore, both species cannot coexist in the same niche.

The principle of competitive exclusion is also called the Gause principle after the name of the Soviet scientist Georgy Gause, who discovered this pattern. It follows from this rule that if two species cannot, due to some circumstances, share their niches, then one will certainly destroy or displace the other.

For example, Chthamalus and Balanus coexist next door only for the reason that one of them, due to sensitivity to desiccation, lives exclusively in the lower part of the coast, while the other is able to live in the upper part, where it is not threatened by competition. Balanus pushed out Chthamalus, but were unable to continue their expansion on land due to their physical limitations. Displacement occurs under the condition that a strong competitor has a realized niche that completely covers the fundamental niche of a weak opponent involved in a dispute over habitat.

Gause principle

Ecologists are involved in explaining the causes and consequences of biological control. When it comes to a specific example, sometimes it is quite difficult for them to determine what the principle of competitive exclusion is. Such a difficult issue for science is the rivalry between different species of salamanders. If it is impossible to prove that niches are separated (or to prove otherwise), then the operation of the principle of competitive exclusion remains only an assumption.

At the same time, the truth of Gause’s law has long been confirmed by many recorded facts. The problem is that even if niche division occurs, it is not necessarily caused by interspecific competition. One of the pressing problems of modern biology and ecology is the causes of the disappearance of some individuals and the expansion of others. Many examples of such conflicts are still poorly studied, which provides a lot of room for future specialists to work on.

Adaptation and repression

The improvement of one species will necessarily lead to a deterioration in the lives of other species. They are connected by one ecosystem, which means that in order to continue their existence (and the existence of their offspring), organisms must evolve, adapting to new living conditions. Most living beings disappeared not for any reasons of their own, but only due to the pressure of predators and competitors.

Evolutionary race

The struggle for existence has continued on Earth exactly since the first organisms appeared on it. The longer this process lasts, the more species diversity appears on the planet and the more diverse the forms of competition themselves become.

The rules of wrestling change constantly. In this they differ from For example, the climate on the planet also changes without stopping, but it changes chaotically. Such innovations do not necessarily harm organisms. But competitors always evolve to the detriment of their neighbors.

Predators improve their hunting methods, and victims improve their defense mechanisms. If one of them stops evolving, this species will be doomed to displacement and extinction. This process is a vicious circle, since some changes give rise to others. The perpetual motion machine of nature pushes life to constantly move forward. Interspecific struggle plays the role of the most effective tool in this process.

Competitive relations.

If in an ecological system two or more species (populations) with similar ecological requirements live together, a negative type of relationship arises between them, which is called competition (? ?). In the general sense of the word “competition” means confrontation, rivalry, competition. In fact, when two populations use the same environmental resources, competition inevitably arises between species for the mastery of these resources. Moreover, each population experiences oppression from the other, which negatively affects their growth and survival and can even lead to the displacement and disappearance of one of them, which is less adapted.

Competition is extremely widespread in nature. For example, all plants compete (compete) for light, moisture, soil nutrients and to expand their habitat. Animals fight for food resources and for shelters (if they are in short supply), that is, ultimately, also for territory. However, if the population is not large and consists of a few, rarely occurring species, the ecological significance of competition will be negligible: for example, in arctic or desert areas there is almost no plant competition for light.

Competition cannot be considered simply by organisms using the same natural resource. Negative interaction can only be discussed when this resource is scarce and when joint consumption has an adverse effect on the population.

Types of competitive relationships

Competitive interaction may concern territory, food, light, shelter and all other types of environmental resources. The outcome of competition is of great interest not only for ecologists studying the processes of formation of the composition of natural communities, but also for evolutionists studying the mechanisms of natural selection.

Competition is divided into intraspecific and interspecific. Both intraspecific and interspecific competition can play a large role in the formation of species diversity and population dynamics of organisms.

Intraspecific competition. Territoriality

Intraspecific competition? it is a struggle for the same resources that occurs between individuals of the same species. This is an important factor in the self-regulation of population numbers.

Do some organisms, under the influence of intraspecific competition for living space, develop an interesting type of behavior? territoriality. It is characteristic of many birds, some fish, and other animals.

In birds, territoriality manifests itself as follows. At the beginning of the breeding season, the male identifies “his” territory (habitat) and defends it from invasion by males of the same species. Let us note that the loud voices of males, which we hear in the spring, only signal “ownership” of the site they like, and do not at all set themselves the task of entertaining the female, as is usually believed.

A male who strictly guards his territory has a greater chance of successfully mating and building a nest, while a male who is unable to secure a territory for himself will not participate in reproduction. Sometimes the female also takes part in protecting the territory. In a protected area, the difficult care of the nest and young will not be disturbed by the presence of other parental pairs.

Defense of territory is not necessarily accompanied by active struggle. Loud singing and threatening poses are usually enough to drive away a competitor. However, if one of the parent partners dies, it is quickly replaced by a bird from among the individuals that have not yet settled. Thus, territorial behavior can be considered a regulator that prevents both overpopulation and underpopulation.

A striking example of intraspecific competition that everyone could see in the forest? so-called self-thinning in plants. This process begins with the seizure of territory: for example, somewhere in an open place, not far from a large spruce tree that produces many seeds, several dozen seedlings appear? small Christmas trees. Is the first task completed? the population has grown and taken over the territory it needs to survive. Thus, territoriality in plants occurs differently than in animals: a site is occupied not by an individual, but by a group of them (part of the population).

Young trees grow, simultaneously shading and suppressing herbaceous plants located under their crowns (this is already an example of interspecific competition (see here)). Over time, an inevitable difference in growth appears between trees: some, which are weaker, lag behind, others? are overtaking. Because spruce? a very light-loving plant (its crown absorbs almost all the incident light), weaker young fir trees begin to increasingly experience shading from tall trees and gradually dry out and die.

In the end, after many years in a clearing, out of hundreds of fir trees, only two or three trees remain (the strongest individuals of the entire generation). But there are no grass anymore, the roots of the trees are spread throughout the clearing, and nothing prevents the lush coniferous crown from being pulled even higher towards the sun.

In some species, intraspecific regulation begins long before serious competition is detected. Thus, a high density of animals is a depressive factor that reduces the rate of reproduction of this population even with an abundance of food resources. (See Part II. Population ecology? deecology.)

Intraspecific competition is an important regulator controlling population growth. Thanks to this competition, a certain relationship arises between population density and the rate of death (mortality) or reproduction (fertility) of individuals. This, in turn, leads to the emergence of a certain relationship between the number of parental pairs and the number of offspring they produce. Such connections act as regulators of population fluctuations...

Competition in biology(from lat. concurrere- collide) is an interaction in which two populations (or two individuals) in the struggle for the conditions necessary for life influence each other negatively, i.e. mutually oppress each other. The most satisfactory formulation is that proposed by Beagon, Harper and Townsend ( Begon, Harper, Townsend, 1986): “Competition is an interaction that boils down to the fact that one organism consumes a resource that would be available to another organism and could be consumed by it.” It should be noted that competition can also manifest itself when a resource is sufficient, but its availability is reduced due to the active opposition of individuals, which leads to a decrease in the survival rate of competing individuals.

Competitors are called organisms that use the same resources for their livelihoods. Plants and animals compete with each other not only for food, but also for light, moisture, food, living space, shelter, nesting sites - for everything on which the well-being of the species may depend.

There are two types of competition: intraspecific competition and interspecific competition. Intraspecific competition is competition between members of one or more populations of a species for a resource when it is in short supply. Competition is extremely widespread in nature. Competition between individuals of the same species living in the same territory is the most intense and severe in nature, since they have the same needs for environmental factors.

Intraspecific competition at one stage or another of the existence of a particular species, it almost always occurs, therefore, in the process of evolution, organisms have developed adaptations that reduce its intensity. The most important of them are the ability to disperse descendants and protect the boundaries of an individual site (territoriality), when an animal protects its nesting site or a certain area, a sexual partner, a place for reproduction, and the ability to obtain food. Thus, intraspecific competition is the struggle between individuals of the same species. Intraspecific struggle for existence increases with an increase in population size, a reduction in the range (territory) and increased specialization of the species.

Examples of intraspecific territorial competition in animals

Rivalry individuals of one species for a food resource, when it is scarce, can be observed in a population of field mice of one species. By searching for and consuming food, mice expend energy and put themselves at risk of being eaten by predators. Under favorable conditions, when there is enough food, the population density increases and at the same time there is a need for organisms to spend more energy to search for food. As a result, the chances of survival decrease.

Intraspecific competition can be expressed in direct aggression (active competition), which can be physical, psychological or chemical. For example, males competing for the right to possess a female may fight among themselves. Show off your appearance to outshine your opponent, or use scent to keep your opponents at a distance. The struggle for females, space and light often leads to active competition.

Territoriality- territoriality. Active dispersal of individuals of the same or different species in space, caused by competition for the space itself and the resources available in it. ( Source: “English-Russian explanatory dictionary of genetic terms”).

Some fish, many species of birds and other animals are characterized by so-called territoriality - intraspecific competition for space. In birds, this competition manifests itself in the behavior of males. For example, at the beginning of the breeding season, the male chooses a habitat (territory) and defends it from invasion by males of the same species (birds singing in the spring is a signal of ownership of the occupied area). This is how males of many bird species determine the competitiveness of their opponents by their voice, and only take seriously birds of equal age or older birds, American ornithologists have proven. In a protected area, care for the nest and young will not be disturbed by the presence of other parental pairs. During the breeding season of birds, the male guards a certain territory, into which, except for his female, he does not allow any individual of his species. And the louder the male screams, the more he will scare the invader, the bird intensifies its singing, and soon goes on the offensive. A couple that has secured a territory has a better chance of finding enough food for itself, and this helps them do everything necessary to breed offspring.

Territorial behavior is understood as a set of signaling means that ensure dispersal and regulate the relationships of owners of neighboring or partially overlapping habitat areas. In different animal species, these signals can be contact or remote (birds singing, wolves howling, grasshoppers chirping, etc.). A set of visual and tactile threatening signals (up to open aggression and fight) is used when neighbors clash on a common border and territory. Many vertebrates use sounds to determine their territory. Male howler monkeys defend their vast territory by producing an extremely loud roar that can be heard 5 km away. Each species of howler monkey has its own special sound. Some animals use a variety of odorants to mark boundaries.

Animals protect their territory with the help of special signs and thereby try to expel strangers from it. Animals mark their territory using sounds, light signals, smells, and also scare uninvited guests with claws, claws or plumage. Animals such as sea lions and elephant seals protect their territory only during the mating season, and the rest of the time they do not show signs of aggression towards other members of their species. Frogs and fish also fight for territory only during the mating season. Everyone heard the evening triads of frogs in the pond near the house. During the breeding season, the male stickleback defends the area around the nest from invasion by other males.

Interesting chemical signals with which animals mark their territory can be observed in roe deer and antelope. In autumn, the Siberian roe deer peels off the bark of small trees and bushes with its antlers, and then rubs its head or neck against them. So she leaves chemical marks on the bare parts of the trees, which are secreted by special glands located on the head and neck. Trees marked in this way indicate to other individuals in the population of a given roe deer species that the territory is occupied or another animal has passed through this area. It is possible that by the intensity of chemical secretions on the mark, other animals determine the time of passage (applying the mark) of the host animal. Sometimes these same roe deer knock out patches of earth with their hooves, leaving a long-lasting smell between their toe glands.

Antelopes on bushes and tall grasses bite off the tip of the shoot and, touching the cut in front of the orbital gland, leave a mark. The large gerbil, as a rule, makes signal mounds, raking up the earth under itself, and irons them on top with its belly, where its mid-abdominal gland, which secretes pheromones (special chemicals), is located. The badger marks the entrance to the hole with a secretion under the tail gland, the rabbit - with the chin gland. Many species of lemurs leave odorous secretions on the branches along which they move.

Some rodents use interesting markings to delimit their territory. The large gerbil, as a rule, makes signal mounds, raking up the earth under itself, and irons them on top with its belly, where its mid-abdominal gland, which secretes pheromones (special chemicals), is located. Two species of singing mice live in the forests of Panama and Costa Rica, Scotinomys teguina And S. xerampelinus, which, like birds, mark their plots with their voices. Both types of mice produce special vocal sounds that humans, however, can barely make out. This is not just a squeak: rodents stand on their hind legs, throw back their heads and produce a series of repeated sounds, similar to a trill.

The movement of house mice occurs along the same routes, thanks to the persistent odors of pheromones released along with urine. On the paws of each individual there are also special glands with which they “mark” the territory. The smell of these glands is transmitted to any object they touch. Urine also serves as a kind of signaling device.

Scientists have established the presence in the urine of rats of not only metabolic products, but also a number of other components - pheromones, which in rats serve as signals that determine the position and condition of the individual.

The muskrat is a sedentary and territorial animal that actively protects its territory from the invasion of neighbors. The boundaries are marked by piles of excrement on high places near the water. The animals also mark the boundaries of their “domain” with gland secretions, the strong smell of which serves as a signal that the area is occupied.

Canines and cats urinate in certain places, thus claiming a certain territory. Dogs mark territory with both urine and feces, thereby disseminating information about themselves that can be obtained by other members of their species. Cats also mark their territory with urine. Cats additionally mark their territory with secretions (liquid) that are secreted between their fingers and from glands located in the area from the corner of the lips to the base of the ear. Marks left by a dog in the form of excrement, the smell of which can be enhanced by the secretion secreted from special glands located in the animal’s anus, do not last long. This secretion gives dog excrement its individual scent. However, this substance carries short-term information, since it has the ability to quickly evaporate. In addition, dogs themselves actively lick the anus, thus getting rid of this smell. With the help of claws and urine, the tiger marks its territory on the bark of trees. Claw prints on the bark carry information about the size and social status of the predator that left them.

Bears mark their territory by rubbing their backs against trees, “hanging” scraps of fur on the trunks. First, they make special track marks: when they approach the border tree, they radically change their gait and leave deeper, more noticeable tracks. Then they tear off pieces of bark from the tree, scratch it and make snacks. At the same time, they can bite a tree at different heights: standing on four and on two legs. In addition, the bear marks its territory with scent marks, leaving gland secretions on trees in the notches of its claws. To divide space, bears often use a loud signal cry. Sometimes individuals simply attack each other.

Stages of development of territoriality:

The first stage in the development of territoriality is the individual space surrounding each individual. It is clearly visible, for example, in rooks perched on a tree, or in starlings in a flying flock. The individual protects it from invasion and opens it to another individual only after courtship ceremonies before mating.

The second stage is a defensible place for living, resting or sleeping in the middle of an undefended activity zone (for many predators of the hunting area). Animals standing on the second stage are distributed almost evenly. These are bears, tigers, hyenas, and also rodents.

The third stage is the rational use of space, where real territories are formed - areas from which other individuals are expelled. The owner of the site dominates it, he is often psychologically stronger than the stranger who tried to enter his territory, and often for expulsion in most cases, only demonstrations, threats, persecution, or, at most, feigned attacks that stop at the boundaries of the site, marked visually, acoustically or smell (olfactory). It was noticed that even smaller individuals expelled larger relatives from their area. It has been repeatedly observed that a much smaller and younger muskrat chased away a larger and older one from its area. Using the examples of other animals, scientists have established that almost always the owner of the site drove away an alien representative of his own species who encroached on his territory.

Conclusion:
Territorial competition in animals manifests itself in conditions where there is no shortage of resources and helps to optimize the existence of each individual of a given species. Each individual maintains its own section of territory and is aggressive towards its neighbors. This leads to a clear division of territory within the population.

Territorial behavior is found in a wide range of animals, including fish, reptiles, birds, mammals and social insects. This phenomenon is based on the innate desire of an individual for freedom of movement in a certain minimum area.

Intraspecific competition

This is competition between representatives of one or more populations of a species. Goes for resources, intra-group dominance, females/males, etc.

Interspecific competition

This is competition between populations of different species of non-adjacent trophic levels in a biocenosis. It is due to the fact that representatives of different species jointly use the same resources, which are usually limited. Resources can be either food (for example, the same types of prey for predators or plants for phytophages), or of another kind, for example, the availability of places for breeding offspring, shelters for protection from enemies, etc. Species can also compete for dominance in the ecosystem. There are two forms of competitive relationships: direct competition (interference) And indirect (exploitation). With direct competition between populations of species in a biocenosis, antagonistic relationships (antibiosis) evolve evolutionarily, expressed by various types of mutual oppression (fights, blocking access to a resource, allelopathy, etc.). In indirect competition, one of the species monopolizes a resource or habitat, thereby worsening the conditions for the existence of a competitive species of a similar ecological niche.

Both evolutionarily (taxonomically) close species and representatives of very distant groups can compete in nature. For example, gophers in the dry steppe eat up to 40% of plant growth. This means that pastures can support fewer saigas or sheep. And during the years of mass reproduction of locusts, there is not enough food for either gophers or sheep.

see also

Literature

• Shilov I. A. Ecology. - M.: Higher School, 1997. - 512 p.
• Ecology. Textbook / ed. A. K. Akhlebinina, V. I. Sivoglazova. - Bustard, 2004. - (1C: School).

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