Examples of the relationship between individuals of the same species within a population

Examples of the relationship between individuals of the same species within a population and between different populations.

Intraspecific relationships:
– attraction of females by males, in which various types of demonstration can be observed: lecturing at black grouse, construction of gazebos at bowerbirds, singing of songbirds, etc .;
– building a nest, feeding chicks from birds.
Interspecies relations:
– food relations: predator – prey; parasitism, competition between species that use the same food, for example, between different species of rodents that live in the same territory;
– mutually beneficial relationship – mutualism.