Competition in nature
Competition (- -) is any relationship between populations of two (or more) species that adversely affects their growth and survival.
In a general sense, the word “competition” means collision, rivalry, competition. Competition is extremely widespread in nature. Species can compete for space, food, light, breeding ability, etc.
Competition is not observed when different living organisms simply use the same natural resource. Competitive relations arise only when this resource is limited and competition for it leads to negative consequences for the population.
Types of competition
Distinguish between intraspecific and interspecific competition. Both types of competition have a significant impact on the species composition of the population and the number of individuals of certain species.
Intraspecific competition is a rivalry between individuals of the same species for vital resources.
This is an important factor in self-regulation of populations.
Example: self-elimination of spruce plantings. The initial distance between plants is maintained only in the first years of plant growth. Then some of the trees begin to lag behind in development due to a lack of light, moisture and minerals. With age, the distance between trees increases more and more.
The result of competition for space in some species of birds, fish and other animals is this type of behavior as territoriality. Territory boundaries may not be visible to humans, but they are well recognized by the animals that set them.
Example: Consider territoriality in birds. In the spring, the male chooses a site and carefully protects it from other males (the singing of birds in the spring is a signal of ownership of an occupied site). A male who strictly protects his area has more chances to successfully mate and build a nest, while a male unable to secure his territory will not breed. Sometimes the female takes part in the protection of the territory. In the protected area, the complex business of nest and juvenile care will not be disturbed by the presence of other parental pairs.
Territorial behavior is essential for maintaining a certain level of the number of individuals in the community.
Interspecific competition is a mutually negative relationship of 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 fierce struggle to almost peaceful coexistence.
Gauze’s principle – of two species living together with the same ecological needs, one necessarily displaces the other.
This pattern has been established empirically and described by the Russian biologist G.F. Gauze. He conducted the following experiments. Cultures of two types of ciliates-shoes were placed separately and together in vessels with hay infusion.
Each species, housed separately, bred successfully, reaching an optimal abundance.
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.
The rule derived from these experiments, the so-called Gause principle, can be formulated otherwise as follows: Gause principle – two ecologically identical species cannot coexist; competition is especially severe between organisms with similar ecological needs.
In the same community, competing species can live together only if their needs are even slightly different.
Example: Insectivorous birds feeding on trees avoid competition with each other due to the different nature of their search for prey on different parts of the tree.
Thus, interspecies competition can have two outcomes:
- either the displacement of one of the two species from the community,
- or the divergence of both species in ecological niches.
This means that competitive relations are one of the most important factors in the formation of the species composition and regulation of the population size in the community.
Interspecies competition can play an important role in shaping the appearance of an ecosystem. By creating a variety of organisms, competition increases the resilience of the community.