Competition

• Competition is an interaction between organisms or species, in which the fitness of one is lowered by the presence of another.

Types of competition

A) By mechanism

a) Interference competition:

Occurs directly between individuals via aggression etc. when the individuals interfere with foraging, survival, reproduction of others, or by directly preventing their physical establishment in a portion of the habitat.

b) Exploitation competition:

Occurs indirectly through a common limiting resource which acts as an intermediate. For example, use of resources depletes the amount available to others, or they compete for space. Also known as exploitative competition.

c) Apparent competition

Occurs indirectly between two species which are both preyed upon by the same predator.

For example, species A and species B are both prey of predator C. The increase of species A will cause the decrease of species B because the increase of As would increase the number of predator Cs which in turn will hunt more of species B.

B) By species

a) Intraspecific competition

Intraspecific competition occurs when members of the same species compete for the same resources in an ecosystem. For example, two trees growing close together will compete for light above ground, and water and nutrients in the soil. Therefore, getting fewer resources, they will usually perform less well than if they grew by themselves.

b) Interspecific competition:

Interspecific competition may occur when individuals of two separate species share a limiting resource in the same area. An example among animals could be the case of cheetahs and lions; since both species feed on similar prey, they are negatively impacted by the presence of the other because they will have less food, however they still persist together, despite the prediction that under competition one will displace the other. In fact, lions sometimes steal prey items killed by cheetahs. Potential competitors can also kill each other, and this phenomenon is called ‘intraguild predation’