Interspecific Relationships - Negative Interactions > Competition

The rivalry between two or more organisms for the same limited resource, where the use of the resource by one reduces its availability to the other, is called competition.

Competition that occurs between individuals of the same species for limited resources is called intraspecific competition.

Competition that occurs between individuals of different species for the same limited resources is called interspecific competition.

A type of competition in which one organism directly prevents another from accessing a resource is called interference competition.

A type of competition in which organisms share a resource but one uses it more efficiently than the other is called exploitative competition.

• Interspecific competition is a major force in evolution, reducing the fitness of species when resources are limited.
• Competition can occur between closely related or unrelated species for the same resources.
• It may occur even when resources are abundant as interference competition, where one species affects another’s efficiency.
• Gause’s Competitive Exclusion Principle: Two species competing for the same resource cannot coexist indefinitely; one will be eliminated.
• Competitive release: A species expands its range when the competing species is removed.
• Competition is generally more intense in herbivores than in carnivores.
• Species may avoid competition through resource partitioning, using resources in different ways (e.g., warblers feeding differently on the same tree).